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Mach Discussion => General Mach Discussion => Topic started by: Davek0974 on May 10, 2016, 10:13:32 AM

Title: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 10, 2016, 10:13:32 AM
Anyone here converted a manual Bridgeport mill to CNC?

After building my plasma table and my mini-mill, both of which are working lovely, I WANT MORE CNC  ;D ;D

The old Bridgeport is looking for some love but is it worth it?

It would need a ball-screw conversion kit, these are available, plus I am guessing servo drives on X, Y and Z so I have encoder display, the knee doesn't seem to get driven on the few vids i have watched so far.

On the plus side, its already driven via a VFD  ;) and i could likely recoup some cash by selling the working power feeds and new DRO i fitted last year.
Title:
Post by: iMisspell on May 10, 2016, 11:46:46 AM
Ive thought about the same for home/hobby use.

While talking with acouple of the mechanicals which are hired at work to fix the cnc machines, they all said the same thing. If you put ball screws in and do it right, you should beable to move the table by hand (grabbing the table itself with your hands and movinging it around) with no serveo/steppers motors hooked up. And with that said, i could not image bringing able to use the machine manually after the conversion, the cutter would be moving the table/part where ever it wanted to.

But then again, ive read online a number of people doing this, so who knows.

What ive thought about doing is making a smaller cnc x/y table which would bolt on my mills table and just convert the Z.

Just some food for thought incase it hasnt crossed you mind.

-
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 10, 2016, 01:40:03 PM
Did a clapped out BP as my first retro and it made a crap machine quite good.
I bought second hand ballscrews off ebay and adapted the dog bone so they fitted.
I converted the quill for the Z.

It was just steppers I used and if I recall I got about 2500mm/min max rapids.

Regarding being able to push it about by hand, doesn't happen. Maybe if you put very course pitch screws on it then it would but 5mm pitch it was more or less the same as it was with the original screws, maybe a wee bit freer.
I went to a fair bit of work to adapt things so I could keep the handwheels, two weeks later I was cutting them off as I never used them, much easier just MDIing and I knew nothing of G Code at the time.

You tend to get good money for manual BP's don't know why as they are not the best knee mills in the world but suppose the name sells them. Used to be able to pick up series 1 and 2 CNC Bridgeports for cheap if they had dead controls, so it was usually better to sell the manual and buy a series 1 or 2 and retrofit Mach to it.

Now however the CNC ones seem to be going for almost as silly money as the manuals so may not be worth trying to do that.



Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 10, 2016, 01:58:22 PM
Thanks guys, results from various forums seem to concur - some say its ok, some say waste of money buy a donor CNC and fix.

It was just a thought really, I will be watching the listings for old cnc stuff and carrying on dreaming in the meantime ;)

In its defence, the Bridgeport is my favourite machine, the things I've done on it have been amazing but have also been bitten by its flexibility as well.

;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 10, 2016, 02:10:50 PM
I wasn't saying not to do it, I meant that a while back the best option was to sell the manual and buy a CNC as it was easier and cheaper to do and often you would end up with more money left over as the manuals sold for good money.
Now however the CNC ones are getting good money so probably not as good an option as previously.

Personally I would look for a bedmill and retro that, sadly they do not come up very often.

My original retrofit was the best thing I did to that BP, as said it was clapped out so it wasn't the most accurate retrofit but it hugely improved it over being a manual.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 10, 2016, 02:24:04 PM
Seems the way it goes, when i got the BP i paid £500, a year later and they were up to over £1000, now they are way more, for a decent item. Getting a donor would be useful as it means i can keep the BP running while fixing/converting the donor, no idea where to put it though :)

Will keep an eye on the 'bay ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: garyhlucas on May 10, 2016, 06:48:09 PM
When you get all done it is still a knee mill, with a really short Z axis. A short Z axis just plain sucks. You wind up spending time and money trying to find a combination of tools all about the same length. I worked on a CNC knee mill for four years. We now have a bed mill with a 21.5" travel Z and we use all kinds of tools without a second thought.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: metlcutr55 on May 11, 2016, 01:06:18 AM
$.02 more...

i ran my 10 x 50 Acra knee mill, knee driven, pc controlled and built by CNC Automation here in NH USA, for 11 years, with NO problems related to the knee driven part.  in fact having the spindle free was the best part.  position over a hole, and mdi hand tap holes small as #2-56 with the tap held in a drill chuck.  or lift the spindle and watch the program run with cutter above part.  also enables you to use a quick change tooling like ultron snapchange, or a power drawbar and TTS type tooling.  no its not a bed mill, but with high positive insert cutters, moderate cut depths and fairly high feed & speed, you can move metal, including steel, at a pretty impressive rate.  if i was doing a lot of tiny short move work, or engraving, id like the quill driven.  otherwise, no.  my acra has 15"+ of cnc Z

it has ballscrews, fat ones at that.  so i dont have to deal with a cnc with old acme screws.  but having said that, i worked with a company for years that only employed big clunky worn out machines.  one of these they retro'ed with an old clunky cnc system.  despite the large amounts of backlash and way slop, this machine never sat empty.  they found ways to program so the looseness wouldnt crash the machine.  of course it could not machine a 30" dia +/- .001 hole, but folks lined up to have that hole put in at +/- .015 tolerance.

and im lucky to have dc brush servo motors already mounted.  but i think 50 ipm of stepper bridgeport would be great, when hand cranking is the alternative.

i did say my acra has 15"+ of Z.  well no it doesnt.  it is electronically brain dead. old like me heh. but im working on it now with the help of a forum member, in a year or less i hope to see it uccnc guided, and using Mach too, and a better machine than when i bought it.  i did a lot of great stuff on her, hope to have her ready when i retire from working for the man which ive been doing for 6 yrs or so, the man has been kind enough, but working for me i like the boss a lot better.

then, after all this fun, theres the lathe in the corner.........
 









Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 11, 2016, 03:28:05 AM
I guess a CNC bridgeport is better than nothing but i really like the idea of having a donor to fix up at my own pace - taking the BP down for any length of time would usually bring in a flurry of jobs needing it, sods law.

My issue would be where to put it while fixing and finding one to buy without dropping loads of cash, don't forget this is still a hobby business not a job-shop. I plonk it in the garden under a gazebo maybe :)

I'll keep looking but it's probably a pipe-dream at present.

It's surprising how little i use the lathe now so wouldn't be my third choice for cnc ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: garyhlucas on May 11, 2016, 10:26:14 PM
$.02 more...

i ran my 10 x 50 Acra knee mill, knee driven, pc controlled and built by CNC Automation here in NH USA, for 11 years, with NO problems related to the knee driven part.  in fact having the spindle free was the best part.  position over a hole, and mdi hand tap holes small as #2-56 with the tap held in a drill chuck.  or lift the spindle and watch the program run with cutter above part.  also enables you to use a quick change tooling like ultron snapchange, or a power drawbar and TTS type tooling.  no its not a bed mill, but with high positive insert cutters, moderate cut depths and fairly high feed & speed, you can move metal, including steel, at a pretty impressive rate.  if i was doing a lot of tiny short move work, or engraving, id like the quill driven.  otherwise, no.  my acra has 15"+ of cnc Z

it has ballscrews, fat ones at that.  so i dont have to deal with a cnc with old acme screws.  but having said that, i worked with a company for years that only employed big clunky worn out machines.  one of these they retro'ed with an old clunky cnc system.  despite the large amounts of backlash and way slop, this machine never sat empty.  they found ways to program so the looseness wouldnt crash the machine.  of course it could not machine a 30" dia +/- .001 hole, but folks lined up to have that hole put in at +/- .015 tolerance.

and im lucky to have dc brush servo motors already mounted.  but i think 50 ipm of stepper bridgeport would be great, when hand cranking is the alternative.

i did say my acra has 15"+ of Z.  well no it doesnt.  it is electronically brain dead. old like me heh. but im working on it now with the help of a forum member, in a year or less i hope to see it uccnc guided, and using Mach too, and a better machine than when i bought it.  i did a lot of great stuff on her, hope to have her ready when i retire from working for the man which ive been doing for 6 yrs or so, the man has been kind enough, but working for me i like the boss a lot better.

then, after all this fun, theres the lathe in the corner.........
 

You are right about the loose quill being very nice. Which is why I said bed mill as they typically have a quill. Since you are only moving the head, with a counterweight up and down instead of the entire knee, table and part you do things like peck drilling a lot better.  I peck drill all the time.  Can't see the point of CNC if you have to stand there watching for chips to wrap around the drill all the time and possibly causing a crash.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: metlcutr55 on May 12, 2016, 01:17:09 AM
Gary, i dont understand your point.  i also peck drilled when i needed to, easy with 15" of cnc "z" travel.  one job comes to mind 5/8" drill thru 6" of 8620 steel with multiple length drill changes, did a lot of these parts.  
another job 1/8" drill thru 12" of cast iron (6" from ea end, and parts held so they extended below the table) also with multiple drill changes made easily possible by the free quill and snapchange holder.  no chip wrapping took place.

when i bought my mill, bed mills were also available, but 25% more than the knee mill i bought.  if i had the $$ id have bought the bed mill, but i didnt have it.  so, like Dave, theres a knee mill project waiting for me in my garage.  im lucky enough to have ballscrews and axis motors in place and more, but from reading this community and looking back on my 40 yrs in all kinds of machine shops, imho a simple stepper mach 3 add on would be a huge improvement to any hand cranked machine, even with old acme screws with high backlash.  one of the reasons i chose the machine i did was it had handwheels.  after about a year, i dont think i ever used them again.  i was 12 years self employed before the $$ crash in 2008 forced me to take a factory job, had i chosen high end manual machinery for my start up, id have failed in a year or so.  cnc is so important.  you cant make a circle on a hand bridgeport or a .5 radius in a corner with a 1/4 endmill.  or cut a 43 deg line.  its harder if the machine is not optimized but its still possible.  cant do that with your hands.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 12, 2016, 06:12:11 AM
Good points there, I have made many large holes - the only way i could do them was to buy a boring head or two and drill with the largest bit i had then slowly cut myself outwards to the finish dia - a fair while when you only have a 1" drill and need a 4-1/2" hole! That would have been a doddle with even basic CNC.

I have a small job i run little batches of - cutting squares on the end of 1/2" rod, currently use a collet block and rotate 4 times - basic CNC would be only one rotation step as it could cut opposing sides easily at one setting.

Looking back, there isn't really much I do that is hand positioned - its all DRO work from zeroes - basically manual CNC stuff, if i want to throw some holes in something I use the pillar drill :)

I think i will dig deeper into this and get some prices for a ballscrew kit.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 12, 2016, 06:35:19 AM
Am i right in my belief that if i want real-time display of position in Mach3, I would need to use servo's and encoders?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 12, 2016, 07:02:14 AM
Am i right in my belief that if i want real-time display of position in Mach3, I would need to use servo's and encoders?

Depends what you mean by "real-time display of position in Mach3"
If simply wanting a display in Mach of position then you could just hook up glass scales and input to Mach set up as Encoder inputs. If using the parallel port then there will be a limitation to the frequency and thus velocity, think 25KHz would be about Max if I recall correctly.

If wanting to have the axis position DROs constantly updated from encoder feedback then you would need a controller capable of doing that.
The CSMIO/IP-A does that but you would need analogue command servo drives (most Industrial AC/DC drives are ).
The Galil, DSPMC, Hicon I think can also update the DROs but not sure if they are "real time".

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 12, 2016, 07:44:31 AM
I was thinking something like the Centroid Conversion where you can still twiddle the table axis handles and Mach3 shows the position change as a DRO.

I guess its not critical, maybe best just to pull the handles off completely and go CNC only, no need to worry about DRO stuff then.

Having seen the ridiculous torque available from the little screws on my mini mill, would steppers with maybe 2-1 or 3-1 reduction be a viable option for a Bridgeport?

Just thinking out loud and looking at pennies etc.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 12, 2016, 08:21:57 AM
CSMIO/IP-A does that, disable drives and move axes by hand and they track.
Only need to home once each time you start Mach, disable the drives and you may see the DROs change, Z especially on my Chiron, it moves a small amount until the brake grabs. X and Y occasionally move as well, tension releasing on belt I suppose.
If you do not have such feedback then every time you disable a drive you really need to re-home, same with E-Stop etc that is true whether servos or steppers.

My BP conversion I had 916 ozin steppers with 2:1 reduction, worked well for many years. Would I personally go steppers? Not a chance Servos all the way for me :D

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 12, 2016, 08:30:22 AM
Similar power on servos?

Just looking at stuff to price up  research etc.


Thanks
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 12, 2016, 08:57:30 AM
You can't compare torques of steppers with Servos at all.
750w servo 2:1 would be fine I would think, 1 Kw definitely. Have heard people saying 400w but I am sceptical about that small.
They will be much more expensive than steppers but once you have had good servos on a machine you will probably not want steppers again :)
I put 1.3Kw Allen Bradley MPL servos on my Series 1 CNC after I took the steppers off and it was probably way more than needed but I had them sitting there anyway.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 12, 2016, 09:07:41 AM
something like this...
http://www.aliexpress.com/store/product/New-Servo-motor-and-driver-set-2-4N-M-0-75KW-3000RPM-90ST-AC-Servo-Motor/314742_760999511.html (http://www.aliexpress.com/store/product/New-Servo-motor-and-driver-set-2-4N-M-0-75KW-3000RPM-90ST-AC-Servo-Motor/314742_760999511.html)

No details on the drive though.

The hardest part is the Z axis on a BP, no perfect solution just lots of workable ideas it seems.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 12, 2016, 10:30:50 AM
Hmm, just had a thought  ;) ...

Instead of my recently dropping around £2k on building a mini-mill/router, what I should have done is use that cash to convert the Bridgeport and fit an adaptor mount that enables me to hold the 24k water-cooled spindle - best of both worlds??

I could even mount a complete custom Z-axis on the rear of the ram where the slotting head should fit!

The BP has a lovely 48" bed, ok maybe it only has 9" of Y axis but that's still not too shabby I think, certainly I've done a hell of a lot of big jobs on the old girl.

So, what would the drawbacks be here?

The new spindle has the speed I need, I think a BP conversion can reach 4-5000 mm/min rapids which is where the mini-mill is set so thats no issue, ballscrews would provide the same accuracy as the mini-mill has presumably.

Hmmm......stupid or not.....?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: garyhlucas on May 12, 2016, 11:20:12 AM
You can't compare torques of steppers with Servos at all.
750w servo 2:1 would be fine I would think, 1 Kw definitely. Have heard people saying 400w but I am sceptical about that small.
They will be much more expensive than steppers but once you have had good servos on a machine you will probably not want steppers again :)
I put 1.3Kw Allen Bradley MPL servos on my Series 1 CNC after I took the steppers off and it was probably way more than needed but I had them sitting there anyway.

Hood

Hood,
This part of what you wrote is critical "They will be much more expensive than steppers"  Everyone compares undersized steppers to  properly sized servos.  Spend the same money on steppers as servos and the results will be much different.  In fact a stepper closer to the ideal driver for machinery than a servo is. A steppers torque is maximized at the bottom end of the speed range, as if you had  a gear box reduction.  A servos torque is lowest at the slow speeds where most of the cutting is done, so you need bigger servos to drive the same load that the steppers would do.  Properly sized steppers do not lose position.  Stalls during cutting are simply a result of steppers too small.  My home built Minimill has 960 in/oz steppers, 80 volt drives with a 1500 watt 68 volt linear power supply and the performance is really very good. I have 18" travels in all directions and easily do 300 ipm even cutting.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on May 12, 2016, 01:43:13 PM
Gary, servo torque is near constant over its speed range, whereas a steppers torque quickly drops of as the speed increases.
The major advantage is the servo performance should be reasonably constant at all speeds, whereas stepper performance will decrease as speed increases.
A well designed stepper system can be as good as a servo system, however it's still an open loop system, unless you use closed loop steppers, but then you're into a similar price range as servos. I priced both options for my knee mill, and from what I remember, a closed loop stepper system was about 80% the price of similar torque servos, and would limit rapid speeds.

Dave, if you were to convert the bridgeport to be capable of those speeds, I'd be factoring in some form of auto lube system while the machine was apart. I wouldn't be wanting to risk slides running dry at those speeds, and even a manual auto lube system will make it far easier to keep things lubed. Arc Euro sell the needed bits at reasonable prices, although I'm sure there are other sources.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 12, 2016, 01:49:41 PM
Yep, its got a lube system already but it would get a total overhaul if i did go ahead.

I'm getting plenty telling me to get an old VMV etc, but my main worries are that they all seem to have small beds, all seem to need too much power and all seem heavy.

While some these may be good traits for a machine, for me they make it hard to use, expensive to run and impossible to move ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 12, 2016, 03:08:16 PM
something like this...
http://www.aliexpress.com/store/product/New-Servo-motor-and-driver-set-2-4N-M-0-75KW-3000RPM-90ST-AC-Servo-Motor/314742_760999511.html (http://www.aliexpress.com/store/product/New-Servo-motor-and-driver-set-2-4N-M-0-75KW-3000RPM-90ST-AC-Servo-Motor/314742_760999511.html)

No details on the drive though.

The hardest part is the Z axis on a BP, no perfect solution just lots of workable ideas it seems.



Not much info there at all, price is very good, maybe too good.
I would see if I could get a manual first to see what the specs and options of the drives are.

Regarding the Z you could do the knee but would need a big motor to push it about unless you can set up some sort of counterbalance. Some of the Bridgeport CNCs used an air assist which supposedly worked well.

I was toying with the idea of doing the knee on my Beaver NC5  as well as the quill, would have been relatively easy as it already has an induction  motor on it for raising and lowering. The  Knee would have been for tool length offsets and quill for normal Z.
Got the Chiron before I got round to doing it so it never happened.  I think I have only used the Beaver twice since I got the Chiron as they were too big for the Chiron.

Downside of a knee mill is lack of toolchanger, some have them such as the Beaver VC5 (I think) and also mc's Matchmaker has one but most don't and even on the ones that do you  have to be careful with tool length selection due to limited quill travel.
 Another downside is mess (coolant and chips) Much worse than when it is a manual machine as you tend to be working it harder and faster.
A friend of mine did an Avon knee mill recently, built an enclosure for it and it works and looks great, heres a link to a couple of pics.

http://www.machsupport.com/forum/index.php/topic,29886.0.html

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 12, 2016, 03:16:03 PM
You can't compare torques of steppers with Servos at all.
750w servo 2:1 would be fine I would think, 1 Kw definitely. Have heard people saying 400w but I am sceptical about that small.
They will be much more expensive than steppers but once you have had good servos on a machine you will probably not want steppers again :)
I put 1.3Kw Allen Bradley MPL servos on my Series 1 CNC after I took the steppers off and it was probably way more than needed but I had them sitting there anyway.

Hood

Hood,
This part of what you wrote is critical "They will be much more expensive than steppers"  Everyone compares undersized steppers to  properly sized servos.  Spend the same money on steppers as servos and the results will be much different.  In fact a stepper closer to the ideal driver for machinery than a servo is. A steppers torque is maximized at the bottom end of the speed range, as if you had  a gear box reduction.  A servos torque is lowest at the slow speeds where most of the cutting is done, so you need bigger servos to drive the same load that the steppers would do.  Properly sized steppers do not lose position.  Stalls during cutting are simply a result of steppers too small.  My home built Minimill has 960 in/oz steppers, 80 volt drives with a 1500 watt 68 volt linear power supply and the performance is really very good. I have 18" travels in all directions and easily do 300 ipm even cutting.

Gary, here is the torque curve of the motors I have on my Beaver NC5, as you can see the constant torque is, well, constant ::)  add to that the peak torque you have in reserve for acceleration etc which is almost 3 times the continuous.


My Beaver mill is basically just a bigger heavier version of a Bridgeport and I have 8m/min rapids (I limited to that as 20m/min was possible) with I think about 800 or 1000mm/s/s accel, there is no way a stepper could get anywhere near that on that type of machine

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 12, 2016, 04:38:48 PM
Thanks, still far from sure what to do really.

Lots have suggested getting a donor, seems there are a few to choose from especially Bridgeport BOSS' and Interacts in various models plus loads of others.

Chances of finding a good mechanics/duff controls donor probably slim though, that still leaves transport and rebuild space etc.

I can see ballscrews setting me back £1500 so getting a donor built with them fitted seems a good idea if less money.

Tough nut to crack i think.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on May 12, 2016, 07:08:20 PM
You do seem to have the same problem as me. Workshop size and power supply are limiting factors.
If I had a high enough roof, and a proper 3 phase supply, I'd have a VMC.

I mostly agree with what others have said about it not being worth converting a manual machine. It's a lot of work, and as has been highlighted over on mycnc, there are knee style CNC machines about for reasonable money.
If I hadn't bought the Matchmaker aka a Shizouka ST-N knee mill that was built from new as a CNC, I would of probably converted something SX3 size, although I did buy a Denford Novamill as an interim machine, which is partly why the Matchmaker retro is still not complete. However I did get the last of the relay holders for the toolchanger pneumatics wired up last week, inbetween trying to get caught up with orders after losing two days getting my lathe turret fixed  >:(
Title: Re: Bridgeport Knee Mill Conversion?
Post by: metlcutr55 on May 13, 2016, 01:15:46 AM
Dave, i have the ball screws and motors in place so i am fortunate, but as i read this thread, its Hoods post #2 page 1 that sticks out to me.  a 3 axis 1200 oz-in kit runs $900 USD, keep it simple & drive what you have, double that figure maybe to make mounts, get pulleys and cables, computer etc, you'd have a cnc bridgeport with backlash.  like those folk i spoke of with the great big machines (the one i spoke of was a planer mill) youd have a machine that could do a lot, but would have limitations.

so for $2000 or less USD, would you have a machine that you'd consider worth that amount?  would its size capabilities make it worth it over your more precise less powerful mini-mill?  if you built it and loved it but hated the restrictions, the flaws could go away one small project at a time, 1st the sloppy x-y acme screws (the z is less a problem, the weight of the knee cancels out the backlash, the knee is always in the most downward position, pulled by gravity.)  then maybe x-y servos, giving you the encoder display (tho most seem to think proper steppers will not skip)

there still seems to be some driven knee doubts.  i can only say mine went up and down for 11+ years, the only motor fail was due to coolant leaking into the motor.  the motor was the same size as the other 2, but the x-y could rapid at 150 ipm, the knee was at 100 ipm.  never a problem.  it does have a rolled ballscrew, but hand cranking it, seems to provide about the same resistance as the bridgeport at work, which is acme screwed but 1 size smaller.

and i must ask for some forgiveness.  in a previous post i made the claim of a 1/8" drill deep drilling some cast iron slides.  isnt true, i looked at the drills which i still have in the shop today.  the 1/8 holes were connector holes to the holes i actually deep drilled which were .218" dia.  big difference, i will attribute it the the 3 olives vodka with ocean spray blueberry drinks i was sipping on.  my bad.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 13, 2016, 02:21:44 AM
Thanks all, yes its all down to space and power I think as primary concerns.

I would not convert the BP without going ballscrew - the screws are knackered and I would want the freedom to climb mill at will without worrying about backlash grabbing the bit, I tried it manually and its a bit scary ;)

I have no idea what I will do yet, this is a growing dilemma - each answer brings more issues.

Probably the only machine will be a BOSS or Interact but did they come with ballscrews??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 13, 2016, 03:22:01 AM
Yes, all CNC Bridgeports had ballscrews and most, if not all, had chromed ways. X travel on the series 1 is only about 18", series 2 was a fair bit more.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 13, 2016, 03:36:11 AM
thanks,

I think height is going to be the killer, they are just too tall to fit in :(

Its looking like my only option is to retrofit the standard machine, the two main stumbling blocks on that appear to be the cost of the screw kit and the way the quill is driven.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 13, 2016, 03:53:34 AM
Heres a few pics of the way I did the Z on mine, it left access to the tilt bolts which I probably never even used after I CNC'd :D
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 13, 2016, 03:54:33 AM
Some more.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 13, 2016, 03:59:13 AM
Thanks, that seems to make sense, what sort of screw dia on that ?

I gather a smallish motor is only needed on the Z?

Still not sure as to stepper or servo, read good things about both, servo's do seem better but at cost.

Also still have to find a screw conversion kit.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 13, 2016, 05:01:45 AM
Thanks Hood, looks good.

I know there is one in there, but the top thrust bearing seems to be hidden??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 13, 2016, 05:20:46 AM
Stepper on Z was 400 ozin or so if I recall.

Steppers work fine if you don't mind max rapids of about 2500mm/min and accel of maybe 150mm/s/s max, or at least that is the most I could get.

Thinking of servos then look on eBay at Samsung Servos, guys in Korea usually selling them at a reasonable price second hand. I had a 400W one on the wee lathe and they are decent drive/motors, made by Samsung/Allen Bradley in Korea.

The top bearing was just a standard bearing sunk into top plate, two angular contacts in the bottom bit.

Recess in the back of the upright plate was to align to the head as the section of the head that is milled away is seeming the bit that is done first and quill is bored to that.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 13, 2016, 05:30:26 AM
Sounds good, yes this two registers on the front of the quill are for position references.

As for speeds, does it really matter on a mill? Most of my cuts are way lower than that as the motor speed is pretty low anyway.

Does acceleration make a difference?

Will check out the servos and thanks again for helping so much, its looking interesting now.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 13, 2016, 06:27:23 AM
Just had a lengthy chat with my supplier of bits and they seem to favour heavily 8NM stepper-servo's for this task. The specs read well, basically a closed loop stepper and DSP drive with variable current etc. Price was about £250 per axis for motor and drive/cable.

Being stepper also means i can use my existing knowledge of BOB's and USB motion controller etc.


More options to throw in the pot.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: RICH on May 13, 2016, 07:19:34 AM
Davek0974,

Link below just for thoughts....it's for the Z on an Atlas mill.

http://www.machsupport.com/forum/index.php/topic,7396.msg127816.html#msg127816

One pic shows the Z driven by using a small stepper ( 80 in oz) using the Z fine feed.
That was no good / don't do as you end up with backlash. Similar to what Hood posted is a 500 inoz 23 stepper mounted to a plate which is attached to the mill head. There is a preload bearing in the mounting block and have no backlash.

Acceleration can become important...ie; For 3d milling you can a have a lot of small
moves in combination moves.

Size wise, the experience from reliable users for stepppers / motors  which provide satisfactory service for "what you want to do" for a "very" similar sized machine is good advice.

If one were to "design" what they want, they would define desired  preformance,calc's would be done, consider experience of others, etc. That will provide confidence in what will be done. It gets rid of the subjectivity in doing the conversion.
Today there are manny programs to assist in doing design as compared to years past
where all was done manualy.

Just some thoughts....

RICH
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 13, 2016, 07:47:22 AM
Nice job there, thanks.

The Z always seems to be the weak link on conversions from what i have been reading.

I am liking the idea of closed-loop steppers, the drivers can ramp the current up/down depending on the load so if there is a tight spot which you get on worn machines it will ramp up to overcome it, if it still can't then it faults out, normal steppers would just stall.

2:1 or 3:1 reduction on X&Y ?

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 13, 2016, 09:32:22 AM
Does acceleration make a difference?

Yes, to show the difference I have just taken a video, same Velocity (20m/min) in both sections of video.
 First section is 1000mm/s/s
 Second section doubled to  2000mm/s/s.

The whole cabin was shaking with the faster acceleration but it is not on level ground and needs shifted anyway. Hopefully it will be a bit more steady once moved :D

https://youtu.be/pVwKnkPx2YA

Will be interesting to see what you can do with the closed loop  steppers.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 13, 2016, 10:08:39 AM
Thanks Hood, pretty snappy ;) I had to de-tune my plasma a fair bit as was shaking itself enough  to give slat-wobble which wrecked the cut.

Don't forget though that this new project is a heavy old milling machine, not plasma, I have no idea what acceleration does to a mill but i'm fairly certain it's not as important as a plasma.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 13, 2016, 10:48:56 AM
There is always going to be a max acceleration that is possible no matter what, it will depend on the rigidity of the machine. There is also the fact that Mach is basically bang bang with the acceleration, full accel, full decell. If it had S Curve then you could likely get much higher accel and things would stay smooth.

Regarding milling, well accel is as important in milling as anything else, the fastest you can get, whilst still being smooth, the better. Most  parts will run quicker with the higher accel and no problems with corner rounding or such like.

On my Bridgeport, when it had steppers I actually got a boost in performance by lowering the Velocity as it allowed me to increase the accelerations, parts ran much faster.
I think it was something like dropping the Velocity from 2500mm/min down to 2400mm/min allowed me to increase the Accel from something like 40mm/s/s up to 120mm/s/s. although I cant be certain of these numbers as it was probably getting on for 8 or 10 years ago.

As previously said my Beaver NC5 runs servos with Vel of 8m/min and accel of 800mm/s/s (just looked to confirm that, first time it has been fired up for a long time :D )
The 8m/min is just what I limited it to as I reckoned for old iron it was fast enough, I did have it cranked up to 20m/min (same as the  Chiron) but it was way too fast for that style of machine.


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 13, 2016, 10:55:24 AM
Thanks Hood, Interesting.

It looks like a series 1 BOSS would fit in, trouble is they are rare now :(

Hmmm...
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 13, 2016, 11:31:06 AM
Don't think there is much difference in height between series 1 and 2. Seemingly you got Series 1 and 2 both with sliding ram head and rigid heads, I have only ever seen the rigid ones here in the UK though so possibly a USA only thing with the sliding ram heads.

Out of curiosity I just set the plasma to old Bridgeport stepper Vel and tried different Accel, funny to think I used to think it was fast. Anyway here is a vid of  it.
https://youtu.be/I3JPAHYCxMk

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 13, 2016, 01:05:14 PM
I'm having trouble finding the correct heights for the various models, so many different series, models and mk's!

Well, nothing wrong with 2500mm/min, provided you only want to cut 12mm thick slabs all day :) Surprising how much sharper it looks as the acceleration went up.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 13, 2016, 04:34:55 PM
Had a look at my manual for the Series 1 Boss I had, says 86" high.

Yes, the faster accel would make a big difference on a job, especially if it had a lot of smallish moves.
Seeing  and hearing it one after the other really shows the difference.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 13, 2016, 04:41:53 PM
Thanks, even that sounds a bit tight, will have a measure tomorrow but its looking like I'll be converting the manual machine I think.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: RICH on May 13, 2016, 11:05:09 PM
Quote
2:1 or 3:1 reduction on X&Y?

Let me answer that this way as it's all a trade off with steppers.

A reduction will increase the steps per unit value so resolution goes
up,torque delivered to the screw will be increased, but the motor must
turn faster for some desired feedrate / rapid move and that can affect
motor acceleration and max velocity. So you need to look at it as a system and
find what is required to accomplish what you want.

Also note that stepper motor curves are done at voltages that may be less or more
than what your power supply may deliver. Higher voltage will increase motor speed
but remember that as speed increases the torque will drop.

That's why knowing what smeone else did with a similar machine is very helpfull.
Even if all is calculated you don't know until the machine is run what you have.
But if you did do some basic design you know things should be satisfactory.

RICH
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 14, 2016, 11:28:13 AM
Story so far based on data collected...

Servo's seem to have won, 750W is recommended size. Ball-screws have 5.08mm pitch so with motors flat out, I think i will go for 3:1 reduction to give me loads of torque, good resolution and 5000mm/min rapids - this still sounds high for an old machine though. The 750W option was recommended buy a 30+ conversion guy so seems sound.

Resolution would be around 0.0006mm/step? Based on 2500 line encoders and 3:1 reduction and 5.08mm screws.

Control options is the nest step, Ethernet smooth-stepper and use step/dir signals OR CSMIO/A and use 10-0-10v analogue - this also offers me actual DRO read-outs for manual knob twiddling. Cost is the factor - £150 vs £480. Both will work with Mach3??

I would prefer the CSMIO option I think as I really want the loop to go right back to the Mach DRO so I get full position read-out in real-time. I can the recoup some of the cost by stripping and selling the new DRO i fitted to the mill a year ago, plus the working but redundant power-feeds and all other bits removed.

Have I missed anything out??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 14, 2016, 11:32:18 AM
You may want to also consider the Encoder module and the MPG module if you go with the IP-A.
It will add to the cost but it will allow you rigid tapping if you ave the Enc Module and If you have the MPG module it will allow you to have a MPG on your panel or have a hand held pendant.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 14, 2016, 11:51:40 AM
Ooh, goodies, goodies, goodies ;)

Looks like either option is around £100 so not a killer.

Issues I see would be getting the encoder mounted to the Bridgeport spindle for the threading unit - there is no clear access to the spindle really, the top is clear for the drawbar wrench and there is little below really, the motor spineless no good as its belt drive and vari-speed. Will need more research here I think, but these look like easy add-ons later.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 14, 2016, 12:01:37 PM
The Enc module will also allow you to make a Tool Height Setter like I have, very useful for setting up tools off of the machine :)

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 14, 2016, 12:15:30 PM
Getting ahead of myself now, does it come with a built-in ATC ;)

Seriously though, this is looking more and more like a project now :)

Even adding the high-speed spindle as a second Z axis OR as I have seen done, adding it as a clamp-on fixture to the main Z axis. This has big benefits for me as it means I only need one machine for all tasks from heavy milling to fine engraving.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 14, 2016, 12:43:05 PM
Ha ha afraid not but even without an ATC the heaight setter is handy, have one for the Beaver NC5 as well, set up all tools I will be using for the job and then when it comes to a tool change machine moves to a position, switches spindle off and I press the power drawbar button and swap tools and then press Start and off it goes :)

Just to add a bit, the ESS is reasonably cheap but by the time you add things such as spindle control board, differential boards for Step/Dir, one or more breakout boards, boards for conversion from 5v to 24v and vice versa  for the I/O then the cost rises quite a bit and ends up getting close to the CSMIO.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 14, 2016, 12:54:49 PM
Yes, i'm pretty much sold on the CSMIO/A direction now ;)

Pricing it all up.

Looking like..

Converting my machine,
750w servo motors,
CSMIO/A control
3:1 reduction on all axes.

With the 5mm pitch screws I think that gives me 5000mm/min rapids and 0.0006mm resolution - silly on an old Bridgeport ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 14, 2016, 01:31:38 PM
5m/min if the motors are 3000rpm ones.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 14, 2016, 01:39:09 PM
Yep, got it - pretty fast for an old machine i think, will have to service the lube system while I'm in there.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 14, 2016, 01:43:38 PM
Will be fine as long as lube is ok. My Beaver NC5 is an old machine as well, similar setup to a Bridgeport and it does 8m/min no probs. Had it at 10m/min for a bit but just thought it a wee touch fast for it so dropped to 8.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 15, 2016, 05:47:37 AM
Control options...

Not sure we need a alpha keyboard for a mill, hows about a touch-screen monitor to do away with the mouse and a small numeric USB keypad?

Or

normal monitor (cheaper/stronger) and a track-ball and numeric keypad?

Looking at controls..
X/Y joystick
Z joystick
Knee up/down buttons
Speed override knob
Feed override knob
Cycle start
Feed-hold
Stop


Spindle motor...
This is currently run from a VFD but only at 50Hz, the head is the vari-speed unit with back-gear so i have 50-3000rpm but in two ranges and manual speed control. Whats a good option here - using the VFD won't address the variable torque ability of the vari-speed unit so can't just lock it in one spot.

Any cool options here to play with?

With a bit of fiddling the vari-speed changer could probably be motorised with a stepper and gearbox, not sure it's worth it?

Mach can obviously take over the Fwd/Rev function - still using the old switch but I wired it to the VFD so I can plug-reverse for tapping;) That was before i got the tapping head.

Any cool ideas?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 15, 2016, 05:59:36 PM
I like full keyboards on all my machines, I always use stainless ones with trackballs. Get them off eBay for reasonable prices but they only occasionally come up so you have to keep your eyes open.

I also have touch screens on all my machines, I usually get them on eBay as well, in fact the one on the Plasma was bought as a lot of 2 for £20 if I recall. They were not listed as touch screens but I noticed a USB socket on them so did some searching and found out that they were indeed touch screens, so snapped them up at the Buy it Now price :)

Personally never used a joystick, much prefer to use a MPG for everything, the CSMIO MPG motion is much nicer than the motion from Mach itself and it is very accurate in all modes unlike Machs MPG Velocity mode.

I fitted a hand wheel to my CNC Bridgeport as the manual controlled air motor was knackered when I got it. It worked fine by hand on the odd occasion I used it but normally I just left it set at one position which tended to suit most jobs.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 15, 2016, 06:01:08 PM
Oh and I personally like a lot more buttons than the few you mention, most machines have at least 9  I think and with the touch screen the others less commonly used can be operated without using the track ball.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 15, 2016, 06:10:28 PM
Here's a few pics of the panels I have on my machines, might oive you some ideas.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 15, 2016, 06:12:03 PM
One last one, this is the big lathe but I now have different buttons above the keyboard and on the right hand panel but the layout is similar, in fact most of the machines have a similar layout as it makes things familiar :)
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 15, 2016, 06:15:42 PM
Found a pic of the button panel that is nowon the big lathe, here it is.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 16, 2016, 02:17:24 AM
That some nice panels there Hood, I think i have only seen one keyboard like that come up and it was about £200!

Will look to go for the MPG module as well and fit jog wheel/selector switches.

This is all a way off yet so i'm collecting ideas of course.

First job is convert from leadscrew to ballscrew...
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 16, 2016, 03:16:25 AM
Just have to keep watching Dave, most of the ones I have were under £30, I once got a job lot of new ones and sold them on via the forum at cost, they went all over the world :D can't recall exactly how much but they were pretty cheap.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 16, 2016, 03:59:36 AM
Thinks something like this might be workable with the MPG module ???

http://www.ebay.co.uk/itm/Universal-CNC-4-Axis-MPG-manual-pulse-generator-Pendant-encoder-fr-Siemens-FAGOR-/251989254779?hash=item3aabbae27b:m:mZvJBBmriCpUkzlG77qf65Q
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 16, 2016, 04:41:58 AM
Yes that would work but some slight rewiring would be required. If using as a hand held pendant (not keen on them myself for small machines) then you would need to fit a button on the feed to the rotary switches. If stripping and placing the MPG and switches on a panel then you do either do as I normally do and fit diodes and an off position or you could again add a button.

If using as a hand held I would probably want a pot on it as well.

Personally I think I would buy a MPG and rotary switches and pots and make my own up, whether for panel or hand held pendant, that way it will be exactly as you want.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 16, 2016, 04:47:39 AM
Handheld does have an attraction here - its a small machine but has a 48" table so the left end could be way out of arms reach when doing edge-finding etc.

Have you a link or any sketches to the wiring etc, I gather the button is needed because we need a pulse rather than the permanent switch output ??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 16, 2016, 04:55:41 AM
Look in the MPG Module manual for wiring diagrams.

The switch is needed if you wish to jog via keyboard at any time, if you dont have the switch then it will be permanently MPG only. On most of my machines I don't  use the keyboard jog except very occasionally. So I have fitted diodes to the  rotary switch for axis selection and take them from each position and tie them together and feed the resolution switches common from them. That way when the Axis select switch is turned to an off position (no connections) the resolution one doesnt get power and Mach is then back to Jog via Keyboard mode.

If you have your panel on an arm that swivels you should manage no problem to get to any end of the table for touch off :) but each to their own, lots of people like hand held pendants.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 16, 2016, 05:26:10 AM
Makes sense, have the manuals now.

That little pendant should fit in perfectly, I'm still leaning away from having a keyboard on the panel, heading towards a small numeric board, MPG, trackball instead.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 16, 2016, 06:03:26 AM
I think i am right in that when going CNC in metric units, it does not matter if the screws are metric or inch pitch as we are just telling it to move X amount of steps etc?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 16, 2016, 06:34:51 AM
Are you just going to use an on screen keyboard for editing code or doing MDI?

That is correct, steps per unit is all Mach cares about, doesn't care what the units are.
If you predominantly use Metric then set up native units as metric and if Imperial then set as Imperial.


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 16, 2016, 06:38:57 AM
Hmm, always a catch, I completely forgot about manual stuff :(

Will keep searching for a keyboard but is there a smarter way to do this - you mention on-screen keyboard, can that be used with Mach3??

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 16, 2016, 06:43:54 AM
Yes you can use an on-board keyboard, in fact Mach has a numeric one, you can use for DROs, built in.
Operator menu the Auto Calculator and then each time, after you have chosen the option, that you click a DRO it will pop up.
It is only numeric though so does not work from MDI.

You can add an on screen keyboard, even Windows has one built in but personally I found they just got in the way and I didn't like them.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 16, 2016, 06:48:31 AM
Yes as i thought - they are a pain unless built in to the app in mind.

I will keep an open view on this part then.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 16, 2016, 07:51:52 AM
Ok, keyboards, once you figure out what to search for, they are there, some are silly pricy though.

Found one made an offer and was accepted so we now have a nice stainless keyboard, a separate stainless track-ball unit and the MPG pendant ;)

Ballscrews on the other hand are like chickens' teeth or rocking horse poo, will be an import job for sure, just trying to find a decent vendor.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 17, 2016, 05:19:27 AM
Using the CSMIO/IP-A,

each button on the panel, limit, etc needs one input on the unit yes?

Trying to work out how many bells and whistles I can play with without adding expansion I/O

Can it use one input for all homes and limits or do limit --/++ need to be separate? The book shows one input each which is a bit of a waste;)


Stainless keyboard just arrived, it's a start I suppose ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on May 17, 2016, 05:41:56 AM
with Mach3 you can have all limits on one input same with home, it just you don't know what limit is hit unless you can see what one is, you can also have home and limits as the same switch, but it a good idea to have home and limits, limits can be cheap switches. home switches for accuracy spend the money
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 17, 2016, 05:45:22 AM
Thanks, will be using servo index homing so the switch quality is not important really.

I guess having a home switch and using soft-limits is just not safe on a big machine?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on May 17, 2016, 06:12:02 AM
if it can rip your arm off all safety stuff should be done
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 17, 2016, 06:24:01 AM
But limits are machine protection not user.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on May 17, 2016, 06:29:06 AM
can be both you can tye it into the door as well if it has one
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 17, 2016, 06:35:37 AM
Yes but what i am saying is - is it ok to rely on soft-limits alone to stop the machine self destructing?

Obviously it will be homed as a first step every start-up.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: RICH on May 17, 2016, 07:30:36 AM
Quote
Yes but what i am saying is - is it ok to rely on soft-limits alone to stop the machine self destructing?

It all depends on the level of protection for the machine that one wants to have and the working environment that they are in.
Don't have any switches on any of my machines, but, they are rather  small and no damage will occur.

If it's for safety then you would want to be  redundant.

RICH
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 17, 2016, 07:36:24 AM
The Soft Limits on the CSMIO's work great and are better than the ones via Mach with the PP or for that matter Mach/SmoothStepper (unless it has changed) and likely a lot of other  external controllers.

The CSMIO Know where the limits are and so will use the deceleration (acceleration) in motor tuning and will stop exactly on the soft limit using that decel. With Mach and the PP you need to set up a slow zone and you have to work that out by trial and error.

Personally I like Limit switches on my machines, I don't like to rely fully on software.
I do not have the limits going to Mach only as that again means you are relying on software.
I have my limits in an E-Stop chain which is totally hardware, ie it goes  via a pilz style safety relay, that relay will stop my servo drives, take away enables from the drives and in addition will also send a signal to Mach to E-Stop, so added safety.



I always have separate homes for each axis and shared limits for all axes, this allows me to have home switches inboard of the extents and can save a lot of moving if the axes are large.
 If you have these home switches stay triggered once reached then you can home from being already on a home switch with the CSMIO, It will see the switch is triggered and will do the back off move only.

Another good thing with  doing that (limits being hardware operated)  is it will always stop if you hit a limit even during Homing.
The way Mach works when homing is it ignores the limits, so if something goes wrong then hitting the limit will do nothing and you end up crashing the axis.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 17, 2016, 07:37:41 AM
Just looking at machine safety.

I think the weak point is the drive belt but still capable of transmitting damaging torque from a 750w servo at 2:1 and doing 3000rpm?

I guess I will find a spot for limits ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 17, 2016, 07:40:20 AM
The Soft Limits on the CSMIO's work great and are better than the ones via Mach with the PP or for that matter Mach/SmoothStepper (unless it has changed) and likely a lot of other  external controllers.

The CSMIO Know where the limits are and so will use the deceleration (acceleration) in motor tuning and will stop exactly on the soft limit using that decel. With Mach and the PP you need to set up a slow zone and you have to work that out by trial and error.

Personally I like Limit switches on my machines, I don't like to rely fully on software.
I do not have the limits going to Mach only as that again means you are relying on software.
I have my limits in an E-Stop chain which is totally hardware, ie it goes  via a pilz style safety relay, that relay will stop my servo drives, take away enables from the drives and in addition will also send a signal to Mach to E-Stop, so added safety.



I always have separate homes for each axis and shared limits for all axes, this allows me to have home switches inboard of the extents and can save a lot of moving if the axes are large.
 If you have these home switches stay triggered once reached then you can home from being already on a home switch with the CSMIO, It will see the switch is triggered and will do the back off move only.

Another good thing with  doing that (limits being hardware operated)  is it will always stop if you hit a limit even during Homing.
The way Mach works when homing is it ignores the limits, so if something goes wrong then hitting the limit will do nothing and you end up crashing the axis.

Hood

I'm getting to like this CSMIO controller more and more and i haven't even bought it yet :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 17, 2016, 07:50:41 AM
Here is a pdf showing he main wiring of my plasma, as you can see I have one button that starts the computer, it then uses the computers power supply to draw in a contactor which feeds mains to the 24v supplies which start the CSMIO and the servo drives logic etc. I then have a Start/Stop button which will bring in another contactor that feeds the mains to the servo drives. And as mentioned I have the E-Stop and limits via the safety relay and also fault signals from my servo drives go to an additional relay in that E-Stop chain.

I do not have the connections from the  safety relay to the CSMIO shown but basically they go to the CSMIO and tell it there has also been an E-Stop, so added safety from both hardware and software. I also have that safety relay  taking away enables from the drives and lastly, also not shown is I have fault signas from the drives going to the servo faults in the CSMIO plugin, again just added safety.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 17, 2016, 07:53:22 AM
oops in the above pdf I do not have a feed showing for the 10amp fuse at the top middle, that gets fed from L1.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 17, 2016, 08:25:42 AM
Nice, do you feel it was needed to have 24v supply for the CSMIO separate from the 24v controls or is it just "good practice"??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 17, 2016, 09:43:31 AM
I think it is required that you feed the actual CSMIO from one supply and the I/O from another if you want to keep the opto isolation, could be wrong though but I am sure I read that in the manual.

On the Chiron I have a big 3 phase supply but it has 2 output channels that are not connected so I used that. On the plasma I got a couple of power supplies, one just for CSMIO, Enc and MPG modules  power side  and a bigger one for all the rest of the 24v (limits, MiniTHC, servo drives logic etc)

I got the ones on the plasma from Eastern Transformers, bought a few of each 100w and 10w as the price was good and I like to have spares.
Looks like I bought the last of them as they only have 5w ones left.
http://www.ete.co.uk/pss-ip20-miniature-series-5w-to-300w--93.html

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 17, 2016, 10:05:42 AM
Yeah its a bit vague - seems you can do both, they say one PSU is fine if there are no big contactors etc. I will get a couple of small pus's probably, I did have a nice PLC quality one here but overkill if it cant do all the job so two smaller ones will be better.

Now, lets complicate the mix ;)

I want/need two spindles here - the main mill quill and a bolt on high speed one - this will be clamped to the main mill quill for starters. Yes it will reduce the Z travel a bit but lets see how it plays before version 2. The aux spindle will only be doing thin stuff and engraving etc so smaller Z travel is probably not an issue.

Obviously when i clamp on the aux spindle it will stop the main Z home functioning so i need two Z homes, maybe two Z++ limits as well?

Ideas -
Two Mach profiles? - The speed setup will be different for each motor, as will offsets probably and other stuff.
A switch for spindle 1 / spindle 2 - changes limits, motor control, vfd power, vfd control lines etc.?

Sounds complex but that's me all over, having this is crucial so I need to get ideas sketched up before I spend cash - it needs to be possible or the project will probably not go ahead. I am 99.9% certain it can be done, just need to get a head round what needs to be done;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 17, 2016, 04:22:38 PM
Two profiles would likely be the best way if you won't be using both spindles from the same code.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 17, 2016, 04:29:33 PM
Yep, will only ever use one spindle or the other. I can definitely see two profiles being needed.

Looking for ways to switch all the lines needed -

Vfd supplies
vfd control and fault lines
vfd speed lines
limit switches for Z axis in two positions
homing for z axis in two positions
cooling pump for 24k spindle
probably others....

The programming for the CSMIO plugin I gather will need to be the same for both profiles?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 18, 2016, 03:31:12 AM
Crunch time, orders to place, money to spend....

Got the screw kit sorted,
Got the pulleys sorted,
Got the controller sorted,
Motors...

Should I fit 750w all round or 750w to the X & Y axes and a smaller 200w to the Z axis ??

Just wondering about the ethics of fitting a big motor to the delicate quill axis.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 18, 2016, 07:30:38 AM
The programming for the CSMIO plugin I gather will need to be the same for both profiles?

No I don't think that will be the case, the info is held in the profile xml I think and it will load each time you pen a profile.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 18, 2016, 07:35:05 AM
OOh, nice ;)

Motors are on order - went for 750w on X&Y and 400w on Z.


Drive belts, was going straight for HTD5 belts but it seems the GT5 profile is better suited to higher power stuff with less backlash, trouble is i cant find a stockist!

The HTD is easy to get but GT ??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 18, 2016, 07:36:47 AM
I would go with the 750w for the Z personally, nothing really delicate about the quill other than the link between ball nut and quill and that should not pose a problem.
If you do go smaller I would say  400w minimum.


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 18, 2016, 07:39:30 AM
Ok, its done now so 400w it will be, if it stalls then I can always fix it later, lesson learnt. I have a feeling it will be ok though, still a 2:1 reduction going in.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 18, 2016, 07:40:43 AM
Not really sure what you are meaning with GT5 is that the Gates belts? If so then BSL or  Brammer  as they are now called should have them.
I just use HTD now and notice no difference at all except cost.
On the lathes spindle I went for a Gates GT3 just because of the power, it is just a 20mm wide belt with 8mm pitch but can handle the 12KW servo no problem at all. No problems in the time I have used it, probably 6 years more.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 18, 2016, 07:43:37 AM
see you already mentioned the motor whilst I was typing my one before last :D 400w should be fine although 750w struggled on the Beaver NC5, think the ballscrew pitch and gearing wasnt helping though and also it is a much heavier quill than a BP one.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 18, 2016, 07:53:58 AM
Im only looking for GT profile as it is supposed to have much less backlash than HTD and be higher power size for size.

I could probably change the motor to 750w still, won't be dispatched for a few days yet??

Yes, just found Brammer and they do them.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 18, 2016, 08:32:11 AM
Ok, I'm sticking with the 400/750w combo on the motors, my reasoning is that the table is a considerable weight with a lot of bearing surface i.e.friction the quill is relatively light in comparison, even with large tooling installed, drilling will present the largest load on it in use, the table does most of the work on a mill, the quill is mainly for tool positioning and plunging. Will see how it plays out.

Drive belts, just had a chat with a very knowledgeable guy and it seems HTD is the best option here, GT is better but more expensive all round. The backlash concern is valid but equates to approx 0.25mm linear which if i have my sums right on 5mm pitch screws and a 75mm pulley will give me an error of 0.0053mm - I think thats acceptable on a 30+ year old machine ;)

He did however strongly recommend going for 8mm pitch and 20-30mm wide belts.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 18, 2016, 02:01:09 PM
Panel controls...Looking for ideas...

As well as the complicated dual spindle system I have to get going mentioned a few posts back, what about things like manual spindle on/off buttons - would they control Mach3 or would they control the vfd directly as well as Mach3?

Also, with the Bridgeport back-gear system, you have run the spindle in reverse when in low range, would there be a smart way to control this from Mach or is it still a manual fwd/rev choice and selector switch on the panel?

Axis ref - hows about a single "Ref" button and a multi-positing knob to select "All - X - Y - Z - Z2"

VFD for main spindle, with the var-speed system I'm not sure if i should try using the vfd as variable or leave it fixed, the top speed is fixed at 3500rpm absolute max as it tends to wreck the spindle bearings above that and low down it probably would not have the torque needed.

So many ideas but not sure of what will work in reality here...
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 18, 2016, 04:53:35 PM
Gates do a nice wee sizing calulator/programme, helps getting suitable belts/pulleys etc if you know a few dimensions of the machine, it is called Design Flex, you will find it here
http://www.gates.com/catalogs-and-resources/resources/repository/engineering-business-applications/design-flex

Regarding buttons,
Spindle should go via Mach if Mach is controlling the spindle on/off. You can do it a few ways with the IP-A, you can use a Brain to look at the switches input and then have it do the spindle toggle, you can use the macropump to do the same or you can set up an OEM trigger to the port and pin number of the switch and under system Hotkeys enter the OEM code for spindle toggle. Personally I use the macropump but the other ways will work fine, just don't use  the inbuilt modbus via brains or macropump and at the same time use Port and Pin via Machs Inputs page as you may get a conflict.

Back gear can be handled under spindle pulleys from  Config menu, just have to choose reversed option for the back gear and set the ratio. Should work fine although I have never used it with the CSMIO.

You could do that for the ref button, you would have to do it either via the macropump or a brain, when it sees the button press it will look at the inputs from the rotary and do whichever option the rotary is set to. I wouldnt bother myself as if I ever wanted to just home one axis I would just use the screen  but everyone is different.

When I had a VFD on the CNC BP I used it to vary the speed and just found a happy medium on the vari pulley and left it there, it was good enough for most things and if doing heavier stuff I would be in back gear anyway.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 19, 2016, 02:20:16 AM
Thanks Hood,

On the BP CNC, when you had the VFD variable, did you have a fixed point that you left the vari-speed wheel set at - I'm just trying to get a handle on Mach calling S2000 but your spindle is only giving 1000 or 3000 because of the setting on the actual pulleys? Wrong speed would make a mess of feed-rates and chip-loads etc.

So maybe set mid-point on the mechanical, mark it on the dial and the calibrate Mach to that point?

I see with OEM triggers we are limited to 15 I think, so maybe Macro-pump is the best way if more is needed, the CSMIO book goes with OEM triggers.

I'm a bit quirky with Ref's, probably just lack of experience and this one will likely be different than the mini-mill, I am making notes of each use on the mini-mill to see just what buttons I do actually use, that should narrow it down. I want just enough buttons on the panel to do some work without having to think about which button to press - panels should be clear and easy to figure in a hurry if needed.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 19, 2016, 04:58:05 AM
I just had manual control of the spindle via a pot but I just found a sweet spot in the pulleys that seemed to be fine for all different speeds (within reason) and left it set there.

So if controlling spindle speed from Mach then you would just decide on a spot for the pulleys and then set Max and Min in Spindle pulleys for that and it should work fine, same for backgear.

CSMIO shows all different ways you can do it, think the extra I/O manual has more explanation that the IP-A manual butthere is also this page whic gives good info for all the controllers and modules..
http://www.cs-lab.eu/en/artykul-128-Digital_and_analog_IOs__configuration__its_easy.html
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 19, 2016, 05:25:11 AM
Thanks Hood,

It might even work out that the speed knob can be left unnamed position and VFD control range would work ok in normal or back-gear setting.

When using pulleys in Mach is there a control setting for this - I can see a "Pulley" DRO on hidden away on the settings page but in the 2010 screen-set it's missing completely.

I guess the "pulley" DRO can be controlled externally via macros or OEM trigger? Will have to get the manual out....
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 19, 2016, 06:14:19 AM
the speed knob can be left unnamed position

Not really sure what you mean by that.

Regardingthe pulleys, either buttons or custom macros can be used, don't even need the DRO to be visible for it to work but would probably be a good idea to add it to the screenset.

Anyway
SetOemDro(56,1)
would set the pulley to 1,
SetOemDro(56,2)
Would set the pulley to 2 etc etc.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 19, 2016, 06:22:18 AM
Blasted autocorrect again, It should say "speed knob can left in one position..." ;)

I have just been playing on my laptop setup and have macros controlling the pulley DRO so that is useful.

Is there a way to stop code execution if speed requested is wrong?

All you seem to get is a message that says "spindle speed too high/low for pulley, using min/max" but that is pretty useless as using the wrong speed can get messy pretty quick.

Really just needs to pause like a tool change maybe then change pulley and press start - can that be done?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 19, 2016, 07:39:34 AM
Ok, you don't want to alter the pot once tings are set up via Mach. Not sure about VFDs but with Servos usually when you choose  a speed input method then others will be disabled so likely you wouldn't be able to use the pot anyway.

You could possibly alter the M3 and M4 macros to look at the commanded speed and pulley DRO and either start the spindle if it is in range or stop with a warning message if it is not.


There is also the spindlespeed.m1s macro, you can do all sorts of things in that :)
I used to have a gearbox on the lathe that had electromagnetic clutches for speed changes, I used the spindlespeed.m1s in conjunction with the m3.m1s for doing that.

Hood
 
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 19, 2016, 08:00:11 AM
By "speed knob" I was meaning the mechanical speed knob on the mill head, my thought was to set that at say 1500rpm and then use the VFD for speeds between 500 and 3000 which are the mechanical limits for normal gear on a BP. Mach3/CSMIO would then control the VFD via 0-10v as well as fwd/rev.

I had not thought of fiddling with the m3/m4 - that would work nicely as I will only have 2 pulleys - high and low or 50-500rpm and 500-3000rpm so the logic seems easy - it would switch the spindle pulley DRO directly and just warn me to change gear on the mill with a message and "press enter to continue"

Thats the sort of control I would like.

The high speed spindle is easy as it will have it's own profile in Mach and I already know the pulley settings etc for that VFD.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 19, 2016, 08:32:05 AM
Hmmm, just messing about here...

should this work in M03.m1s...

rpm=GetRPM()
pulley=GetOEMDRO(56)

If pulley=1 then
  if rpm>500 then
    Call SetOEMDRO(56,2)
    MachMsg ("Change Back-Gear To High Range","Pulley Error",0)
  end if
else
  if rpm<500 then
    Call SetOEMDRO(56,1)
    MachMsg ("Change Back-Gear To Low Range","Pulley Error",0)
  end if
end if
DoSpinCW()

The result I get on my laptop setup is that GetRPM() is not reading the S-word from the code line "S1500 M03" for some reason??

Maybe I am not clever enough yet ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 19, 2016, 09:38:19 AM
Seems it IS reading the S-word BUT only if it is < the current pulley Max limit.

So if pulley set is 0-1000rpm and I call S500 M03 the speed is read as 500

But if I call S2000 M03 the speed is read as 1000.

Seems odd.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 19, 2016, 10:39:37 AM
Found it....

It has to be done in SpindleSpeed.m1s....

rpm = GetRPM()
pulley=GetOEMDRO(56)

If pulley=1 then
  if rpm>500 then
    Call SetOEMDRO(56,2)
    MachMsg ("Change Back-Gear To High Range","Pulley Error",0)
  end if
else
  if rpm<500 then
    Call SetOEMDRO(56,1)
    MachMsg ("Change Back-Gear To Low Range","Pulley Error",0)
  end if
end if

SetSpinSpeed( rpm )

Seems to do exactly what i want - pulley 1 would be low range, 50-500rpm and it warns me if the current set pulley is wrong, pulley 2 would be high range 500-3000 and it warns me to move machine into high range.

Nice
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 21, 2016, 11:06:42 AM
After messing with the speed control and vfd settings today , I have a sort-of workable solution but there are drawbacks - the head has some issues with worn bushes, the speed range is a bit limited, power will be affected. I also only have the smaller 1.5Hp 1440rpm motor which is odd as I thought I had the 2Hp model, oh well.

So, improvements... Is a servo motor torque really linear from zero to rated speed?? I.e. will a 1.5kw AC servo really give me 1.5kw or 2Hp at 100rpm AND at 3000rpm or have i read it wrong??

Would I be better off just fitting a 1.8kw AC servo motor for the drive and connecting at 1:1 ratio??

If it was correct then I would have full power from 1 to 3000rpm at the spindle - sounds ideal.

Would this play well with my upcoming CSMIO/A conversion - would Mach give speed control and correct rpm readout??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 21, 2016, 11:34:22 AM
Torque is the constant, not power.

The IP-A works great with servo spindles :)

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 21, 2016, 12:11:13 PM
It shows about 6Nm from the servo and listings show about 5.5Nm from a standard AC motor on a VFD of similar power so I am guessing a 1.8kw AC servo will be a decent replacement and also mean NO back-gear etc - full power across the board :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 21, 2016, 12:19:42 PM
Something like this...

http://www.aliexpress.com/store/product/New-5N-M-1-5KW-3000RPM-110ST-AC-Servo-Motor-110ST-M05030-Matched-Servo-Driver/314742_760988112.html
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 21, 2016, 01:05:25 PM
As said the power would not be constant, the torque would be though.
You do have approx 3x constant torque for short periods, how long would depend on the drive as well as the motor but it would not be long, more for acceleration really.

So a similar Kw servo  and an AC Induction motor via VFD, the servo would be better but not as good as the induction motor via the gearing, reason being the induction motor would always be at the rated Kw no matter the spindle speed.

I have a 3.5Kw Servo  on the beaver mill and it is fine without back gear but much smaller and I would have my doubts, suppose it all depends what you will be doing.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 21, 2016, 02:02:59 PM
I was comparing kW and Nm from AC servo to AC motor.

I thought 6Nm was 6Nm regardless but the servo would do 6Nm at 100rpm and the same at 3000rpm whereas the AC motor would ONLY be 6Nm at 1450 or whatever it was rated at - am i wrong? Obviously not grasped the whole power - torque thingy yet;)

Most of my stuff is done without back gear, only really used it when running the big fly-cutter but don't use it now as not building steam engines anymore.

I tried one of my normal jobs with the mechanical control up high and the motor down low - pretty much the worst case scenario and it worked fine so I should guess that a 1.8kw servo would be better as no de-rating and less transmission losses.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 21, 2016, 03:12:51 PM
Ok the servo will have a continuous torque rating, 5Nm in the one you linked to, and 15Nm peak.
The Kw will only be at rated speed however, slow the rpm down and the Kw will drop.

It is exactly the same with an induction motor and a VFD when looking at the Kw but the Torque will also drop so the servo is better.

Now what you have at the moment is a VFD running an Induction motor but you are just using the VFD as a phase converter as you only vary the speed via the pulleys.
That means the motor is always running full speed so the Kw will always be the rated Kw. The torque however will vary as you adjust the pulleys, drop the spindle speed from 1440 to 720 and the torque has increased by two, Go the opposite was and run at 2880 and the torque will have halved.



I made a spreadsheet up a few years back to work out torque or Kw  of a Servo when I only knew one or the other along with the rated RPM, I have attached it below.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 21, 2016, 05:24:40 PM
Will check spreadsheet tomorrow, thanks

But isn't torque what i need here?

Surely it does not matter if it takes 1kw to create 5Nm or 3kw - the torque is what does the cutting and kw are what is required to create that torque???
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 21, 2016, 05:43:19 PM
Kind of hard to explain but you need a certain torque to do something,  but you also need a certain power to do it at the speed required.
Probably not a good explanation, will try and think of a better way to explain but don't hold your breath :D

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 21, 2016, 05:47:13 PM
Ok look here
http://www.kennametal.com/en/resources/engineering-calculators/holemaking-calculators/tapping-torque-and-horsepower.html
You will see the torque required for tapping and you will also see the power required to do it at the surface speed required by the tool.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on May 21, 2016, 07:57:00 PM
A simplistic generalisation is electric motors produce reasonably constant torque across their rated speed.

With varispeed, your 5Nm motor will result in a varied level of torque at the spindle. At say 145rpm spindle, and the motor running at 1450rpm, you have a 10:1 ratio giving you 50Nm torque at the spindle. Going the opposite way, and running the spindle at 4350rpm you have a 1:3 ratio, so you only have 1.67Nm torque at the spindle. With varispeed, you always have the full motor power available at the spindle.

Now if you go direct drive, you only ever have 5Nm available at the spindle. You will only get full power at full rated speed. Half the speed, you only get half the power, but still 5Nm. Quarter the rated speed, quarter the power but still 5Nm.
This is why most VMCs have such high power spindles. If they didn't, they simply wouldn't have enough torque for tapping, or large cutters/drills
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 22, 2016, 03:37:24 AM
Thanks Hood, that calculator rammed it home, seems with a 5Nm motor it would only be able to power-tap to M8 in steel, in reality thats not too bad as I probably would not expect it to do anymore than that on the original head, I always hand-tapped the big stuff.

Now if you go direct drive, you only ever have 5Nm available at the spindle.

Got it.

You will only get full power at full rated speed. Half the speed, you only get half the power, but still 5Nm. Quarter the rated speed, quarter the power but still 5Nm.

This is where my brain fogs-over again - does the lower power matter when cutting or does it just mean less electricity is used to do the work?

If my calculator says i need 4Nm to do a task at 100rpm and the motor is rated 6Nm at 3000rpm - it will do the task easily yes?

This is why most VMCs have such high power spindles. If they didn't, they simply wouldn't have enough torque for tapping, or large cutters/drills

That bit makes sense now, thanks.

Moving on, it would seem if i want to keep all my (theoretical) power, I would need a 3.8kw / 15Nm servo - this is possible BUT I would not have the power to reliably run it along with the table servos etc at full whack the spindle would need 14A alone - back to square one but lessons learnt and no money spent, thanks guys.

So it seems my choices are to use the original vari-speed head and fix the worn out bushes, or try and find a step pulley head which so far has been unsuccessful.

With a step pulley, Mach would know what pulley it was in from the last run and the VFD could give a useable speed range from G-code, my little macro tweak from earlier would tell me what pulley to switch to depending on code.

OR

Use the (repaired) vari-speed head as a step pulley - mark the speed dial 1 - 2 - 3 and instead of changing pulleys, just twiddle the knob to that setting and again use the VFD - this sounds like a reasonable idea to me??

What you reckon....
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on May 22, 2016, 03:58:23 AM
Have a search over on the home shop machinist forum, as I seem to remember John S(tevenson) posting about overhauling his POS Bridgeport varispeed head a while back.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 22, 2016, 05:23:56 AM
Quote
This is where my brain fogs-over again - does the lower power matter when cutting or does it just mean less electricity is used to do the work?

If my calculator says i need 4Nm to do a task at 100rpm and the motor is rated 6Nm at 3000rpm - it will do the task easily yes?

I may make things worse by trying to explain but....

Ok you need the torque to do the job but you also require the horsepower to do it in the required time.
The tapping calc I linked to can maybe make you think it is all surface speed but you also have to take into account the feed per rev, a tap has a fixed feed per rev due to the pitch, a M10 has to move at 1.5mm per rev.

So you need the torque to drive the tap round but you also need the horsepower to feed it at 1.5mm per rev.


So you may have enough torque to twist the tap in the material but you may not have the required horsepower to feed it at the required rate.

See, told you I would probably make things worse :D

Regarding your  bushes, I may have a kit, bought it for my series 1 boss but never used it, not sure if it is the same size as the 2J head or not?
I could measure the bushes if you want.


Regarding the power, you will probably find you have plenty, my Computurn lathe has a 12Kw servo for the spindle, 2x 3Kw motors for axes, a 0.5Kw servo   for the turret and various other motors such as oil pump (0.75Kw) Coolant etc etc. The Chiron has 3x 2Kw axes motors , 8Kw spindle, and coolant pumps as well as other electrical stuff ( on both machines) such as lights, and all the components in the cabinet. Both machines are  via a 32 amp breaker (C Type) and I often run both machines at the same time with no issues.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 22, 2016, 05:52:48 AM
Ok here is maybe an analogy that helps explain it better, or maybe not ::)
You have a shaft with a rope round it and a drop with a weight attached to the rope.
You turn the shaft with your hands and say it requires 1Nm to turn the shaft to lift the weight, so no probs you can easily apply 1Nm. so you will be able to lift that weight.
Where the power comes in is the time it takes to lift that weight a given distance, so say the max power you can apply lifts the weight a given distance  in 1 minute.

 Because that is the max power you have then it can not be done any faster but you need to do it in half the time.  (drill or tap or cutter needs a certain feed per rev)  so you get your twin brother to give you a hand, you now have double the available torque but you don't need any more torque so that doesnt make a difference.
 You however also have double the HP so you can raise that weight the same distance in half the time.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 22, 2016, 06:01:59 AM
Thanks Hood, the analogies do actually help ;)

One thing I had omitted in my last post was that I still have the back-gear for low-speed high-torque as before so maybe I really don't need such a large servo, just one that will cover down to say 500rpm and then drop into back-gear for the heavy stuff.

Or is it better to just stop polishing the turd and use the vari-speed head as a step-pulley with the additional range variation by VFD??

This is a tougher decision than fitting the damn ball-screws!

I guess the servo spindle is always a future-fit option if i leave room in the cabinet etc.

Or i could fit a roof extension to the shop and get a proper machine which probably would cost less ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 22, 2016, 06:21:23 AM
What may also help is the actual definition of 1 HP.
It is the amount of power required to lift 33,000lbs a distance of  1 foot in 1 minute. So if you have 2HP you can lift that same weight (mass)   1 foot in 30 seconds or 2 feet in one minute.
Pushing a drill into material will be the equivalent of the weight/distance/time, it is the force needed to push that drill the required distance  at the required feed rate.


Using backgear would  allow you to use a smaller motor, as said I have a 3.5Kw on the Beaver mill and have never needed to use the back gear, if you went for a 1.5Kw then used the back gear when required you will probably be ok.
I cant recall the ratio of the back gear on the BP's but think the Beaver is 10:1.


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 22, 2016, 08:08:35 AM
Thanks, that helped a lot ;)

Had another play before I started tearing her down for a full strip/repaint/rebuild ;)

If I kept the existing power setup, there is a possible working option where I can set the head at two positions - 700 and 1500 and then using the existing VFD I at a reasonable 25Hz to 75Hz range I can get full speed variation from 40rpm in back-gear to 3000rpm in high - having the vari-speed in there to multiply the torque where needed allows for power lost in running at lower Hz it seems it would all work.

HOWEVER, it's not as much fun as having just one high range and one low range with the luxury of full G-Code control - the main question is - is it worth the £400 approx. that it will cost to do the conversion???

The input shaft on the head is a nice 1.375" so no issue getting a taper-lock pulley on there, the motors seem to be 19mm so again no issue, 1:1 poly-v pulleys and belt would do it along with a new motor mount plate.

As it is it's going to need new bushes for the sheaves and a new main belt at least, not finished stripping yet.

SO, what would you guys do - rip it out and splash the cash on luxury OR repair and refit??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Tweakie.CNC on May 22, 2016, 08:39:11 AM
Quote
SO, what would you guys do - rip it out and splash the cash on luxury OR repair and refit??

As it's all your money Dave - 'splash the cash'.  ;D

(you asked for opinion).

Tweakie.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 22, 2016, 08:42:49 AM
Ideal world is Servo big enough not to need to worry about back gear.
Ideal isn't always practical though :D

Ok so I have this bushing set you can have if it fits, see pic.

How much would a new belt cost though?

Regarding driving with servos, on my machines I have fitted timing belts, if going 1:1 and using the motors encoder for feedback then it is best that it can't slip. If you have an encoder on the spindle itself then doesnt matter if it slips.


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 22, 2016, 10:17:25 AM
Thanks for the parts offer Hood, appreciated, they do look like the right bits.

I will price it up correctly tomorrow with timing pulleys, what size belt - 25mm x 5 or 8 pitch?

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 23, 2016, 04:09:45 PM
Ok, I'm holding the alterations to the spindle drive for the moment, will keep the vari-speed and modify later - better things to focus the cash on.

Drives and motors...

These are the drives... http://www.aliexpress.com/store/product/New-Servo-motor-and-driver-set-2-4N-M-0-75KW-3000RPM-90ST-AC-Servo-Motor/314742_760999511.html

I have one on the bench for testing with the CSMIO and an old Mach3 setup.

Do servo drives need any setting up ? I have set the motor model in the drive but the rest of the million settings? Never used a servo before ;)

Anyone know these specific drives?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 23, 2016, 04:36:21 PM
There will be lots to set up, such as I/O, command input type etc and also you will need to tune the motor/drive and then once that is done you need to tune the IP-A, assuming of course it is the IP-A you got.

Do you have a link to the manual?
Does it have set-up software or is it all via the front panel?

If you want that bushing kit for the vari pulleys just send me your address via PM.
Hood

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 23, 2016, 04:56:24 PM
Yes I have the CSMIO/IP-A plus the MPG add-on.

Manual attached

It can have pc setup but no idea how, otherwise done through front panel
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 23, 2016, 05:05:19 PM
Connecting will be no problem as long as you have a computer with a serial port or if not a USB to serial adapter.
Just connect pin 5 on drive  to pin 5 on DB9 connector  and then pin 2 on drive to 3 on DB9 and 3 on drive to 2 on DB9.

Don't suppose you have a link to the software as well?
Usually much easier to set things up on a laptop rather than use the front panel but it depends how user friendly the software it. The Allen Bradley software (UltraWare) is quite nice  but the software for the drives I have on the Chiron is a bit less so, still easier than front panel though :)

Did you get the drive/motor from that link you attached? seems very quick delivery if from China.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 23, 2016, 05:14:23 PM
Oh looked at the manual for the serial connections, dont connect as above LOL, the connection on the drive is not a DB9 like most.

Ok so it will be
pin 5 on drive to pin 5 on DB9
pin 1 on drive to pin 2 on DB9
pin 3 on drive to pin 3 on DB9
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 02:11:02 AM
Yes the kit came from that supplier - he is extremely fast and good stuff too.

I only have a MAC laptop so will need to do front panel setup i think.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 02:42:41 AM
Hmm, going to need some help on this setup i think...

I have the motor, drive, controller connected, I can see the X axis encoder changing the DRO when i twiddle the spindle but when i take Mach out of reset the DRO stops changing?

There is no motion and the drive does not lock.

Probably a signal error?

Don't know if out/ins are active high / low from the CSMIO?

When out of reset there is 24v on the enable output.

Where to start here??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 24, 2016, 03:05:05 AM
Ok you could use your computer for the machine to configure withthe software if you wanted, doesnt have to be a laptop.

Some drives, especially the Asian drives, have sourcing inputs which would mean they have to go to 0v to be active, not sure about yours would have to look.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 24, 2016, 03:17:28 AM
Yes, looks like sourcing inputs so you have to take them to 0v to enable them.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 03:26:00 AM
So that is active low?

what i get is encoder input when Mach is in reset, when out of reset no encoder activity.

no lock up

no movement

I am pretty certain the wiring is ok, I have connected as per CSMIO dig

Enable output
Reset output
10-0-10v outputs

Fault input

all encoder lines + ground

thats where it gets a bit fuzzy - what Ins and outs should be enabled in ports & pins etc?
distinct lack of help in the manuals, probably the difference in going from simple step/dir to servo.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 24, 2016, 03:42:20 AM
The outputs on the IP-A are Sourcing outputs, ie they put out 24v when active , your drives inputs are sourcing, they also output 24v which you have to put to 0v to make active. You will have to make an opto board or use relays I would think.

For testing you could just use a switch or even just joining the Input for the Run to the 0V of your supply, obviously Mach will not be controlling it.

Bit of a PITA that the Asian drives work this way, most European and USA drives have sinking inputs although some can actually be switched, my Lexiums can (just all though, not individuals)

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 03:53:09 AM
That is really confusing, so you cant go straight from CSMIO to the drive, have to fit relays?

On all ins/outs??

what a bummer.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 03:57:48 AM
Ok, i pulled the enable and reset lines from the CSMIO and stuffed the enable into 0v and the motor started creeping so there is life here ;)

however no difference on jog from mach

and the encoder still stops showing when i go out of reset??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 24, 2016, 03:58:20 AM
The drives outputs look like they sink and on the IP-A the inputs can be used either way so you are fine with the drives outputs to IP-A Inputs.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 24, 2016, 04:49:42 AM
Have you got the drive configured as analogue input?
Didn't see any mention of tuning in the servo manual but you would normally have to tune it and then tune the IP-A.
Not sure what you mean by encoders stop, is that the DROs in Mach, the readout on the drives screen, count in plugin?


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 05:08:43 AM
errr, not sure will have to look at that.

no idea on tuning, not done any, cant see any mention in manual

when mach in reset the encoder alters the DRO in real-time when motor twiddled
when out of reset the DRO does not alter any more when motor twiddled
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 05:20:45 AM
looks like it's -10 - 0 - 10v only.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 24, 2016, 05:54:43 AM
Ok if you have it set up for -10 0 +10v command then that is correct.
Not sure why it is stopping outputting to the DROs in Mach but as it is showing whilst Mach is in reset then it may be that the IP-A is not configured correctly.
If you attach your xml I can have a quick look.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 05:58:18 AM
Ok, will do.

Where it is now, i take it out of reset, press left or right jog and i get the "ePID error" come up and it goes into reset, the motor does not move.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 06:01:10 AM
XML attached
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on May 24, 2016, 06:04:10 AM
Is there setting software available for these servo drives?

I know with the Kinco drives fitted to my lathe, the software lets you flip the active high/low settings for inputs and output, which you couldn't do via the front panel. Or at least if you could, it wasn't mentioned anywhere...
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 06:16:28 AM
I think there are pn settings for output/input states but i have it on manual control for enable now and all others disconnected.

I need to get movement I think before going into controls.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 24, 2016, 06:27:32 AM
Ok you will have to tune the IP-A, that will be why you get the ePID error most likely.

xml looks fine from a quick look although I am unable to see the tuning settings as you can only view if you have a controller connected.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 06:37:35 AM
But can i tune without any motion ??

Do i need to get jogging before tuning??

I have no motion at all yet from the keyboard.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 06:59:17 AM
Ok, i did an auto-tune in CSMIO and we now have some sort of motion :)

It does state that the drive has to be tuned first but have no info at all on that yet.

Also what about steps per - i just followed the CS manual.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 24, 2016, 07:10:23 AM
Steps per will basically be whatever you want at this stage as you are just bench testing.
Think you had it set as 2000.
Your encoder is likely 10,000 per rev so if direct coupled to a 5mm pitch screw then 2000 would be correct.


You do realise once you have this hooked to the machine you will have to retune again :)

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 07:14:40 AM
Yes of course, it needs tuning in the final condition. Just waiting on a reply from supplier about tuning the motor/drive loop.

How solid should the "lock up" be on a servo shaft?

It can be wobbled about but always goes back where it started.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 24, 2016, 07:18:24 AM
You should not really be able to twist the shaft at all if it is just the shaft with no pulley.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 24, 2016, 07:32:20 AM
Personally I would be setting up the software to see what is in that. You could use the computer that has Mach on it.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 07:34:51 AM
But....


there is no software i am aware of, certainly nothing comes with them and the site has no downloads menu??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 24, 2016, 07:36:35 AM
Yes, looked at the site and no info at all, sadly typical of Chinese stuff.
Hopefully the seller will get back with some info soon.

Hod
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 24, 2016, 01:55:51 PM
Might not be too bad - it seems the motor side is set when you enter the motor code into the drive.

Will leave it there while testing at least, plenty more to sort out ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 25, 2016, 04:26:21 AM
Wiring check...

Power supplies, one for the CSMIO and one for the inputs/outputs to maintain isolation?

The outputs on the drive are sink outputs so i would connect the +ve pin on the CSMIO input channel to 24v and the -ve to the drive?

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 25, 2016, 06:28:23 AM
Also...

The cable from the drive to the CSMIO - probably about 2' long at most, shows twisted pair for the encoder lines - is shielded multi-core ok here?

I have a pile of Centronics printer leads in the box, these have nice moulded DB25 plugs on the end - saves soldering those horrible plugs up.

Fully wired so all 25 cores are connected, any good??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on May 25, 2016, 06:41:00 AM
shielded is good just have the shield connected at one end only going to your common 
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 25, 2016, 10:21:37 AM
Limitations of the system?

When i was building the large scale traction engines, everything was made with a tolerance of only 0.1mm or better - easily obtainable on a hand controlled Bridgeport with a three digit DRO. It really was not needed to go tighter on these engines and many say that if too tight they never worked properly due to expansion when running etc.

Anyway, the third digit on the DRO was pointless as you could never set that precision by hand and merely looking at the mill out of the corner of your eye made it wobble more than that!

So, now (when done) I will have ball-screws and servo's with Mach3 acting as my DRO display - this is all running on my bench very nicely now.

But - the encoder/motor is connected to the screw via a toothed belt - surely this must introduce an error possibility, especially with a 100kg sitting on the bed??

My main point here is - If i want to use the mill manually, say to drill some holes without cam-ing the job, I can put Mach into reset, this drops out the servo motors and i can spin the handles like before and Mach tracks the position on screen - I am hoping here that this is a workable situation with decent accuracy when positioned manually??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on May 25, 2016, 03:50:18 PM
I have heard of people saying they are going to do this but never do
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 25, 2016, 03:57:05 PM
Thinking on it more - the hand wheels are on the screw ends so when using it manually, all the torque goes straight to moving the load - the belt only transmits position back to the encoder/motor.

I am confident it will work out fine, just over-analysing as usual :)

I've just about pulled everything off the mill now, DRO will be sold to raise funds ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 26, 2016, 09:26:34 AM
Ok, where did I slip up...

Previously had the motor tuning set as book, 2000 steps per (10,000 / 5mm pitch)

When I fit this on the machine it will be at 2:1 ratio so i set steps per to 4000 (10,000 * 2 / 5mm pitch) and set velocity to 7500 (3000rpm / 2 * 5mm pitch) acceleration is at 750mm/s/s

Works ok in jog mode, works ok in code mode at speeds up to 7500mm/min

If i do a "Goto zero" it runs for a while then stops with ePid fault.

It also allows me to set feed higher than it can handle and then goes into ePid fault.

Is there a reason here?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 26, 2016, 10:53:26 AM
Ok, found it - it seems it does not like running right at the limit of max speed - if kept just below max it all works perfect.

If I set the max at 7500 and command a feed at 7500 it faults, if I set 7400 it works perfectly in all modes.

Wont get that high in real life as the mill bed is not really big enough.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 26, 2016, 02:01:02 PM
Just catching up, so you say that you do not have any means to tune the servo other than what it automatically chooses when entering the model number?

Regarding the manual usage, MDI I find is much easier and cleaner than winding handles. When I did the manual conversion I went out of my way to keep the handles, hacked them off with a grinder a week or so later as they had never been used and really were just a hazard.
If determined though then I am not sure why you think there would be an issue even if the handles were on the motors, timing belts should not have any stretch in them at all as they are reinforced with fibreglass or kevlar strands or some even steel.

Encoder wiring should be fine with shielded multi-core but best is definitely twisted pairs.

Sounds like it may be a tuning issue if you get  the PID error at max RPM.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 26, 2016, 02:10:50 PM
Hi Hood,

I'm not too sure re the tuning - i mailed the seller who asked the supplier and the reply was that it was set by entering the motor code. There may be parameters but thats way beyond me.

yeah i think it will be fine, probably just didn't have enough coffee that day ;)

The wiring will only be a foot or so long and seems to work ok on the bench at 5' long so will give it a go - looks neater with moulded plugs too.

The error may also be because of running flat out with no load on the motor maybe?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 26, 2016, 02:18:05 PM
The error may also be because of running flat out with no load on the motor maybe?

Shouldn't be, can run servos flat out at insane accelerations with no loads.

You could possibly try from the drives front panel to jog at 100% and see if it causes any issues., if it does run fine that way then likely it is needing tuned a bit better in the IP-A.
If however the tuning in the drive itself is not great but the drive has a large following error then it may run fine in the drive but you may have problems getting tight tuning in the IP-A because of that.

Hopefully you will get some info on what options there are for tuning etc.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 26, 2016, 02:31:58 PM
Will have a play tomorrow, thanks

Couple of build q's...

What size fuse should i use for servo with a 750w motor ?

The PC - strip and build into the operator panel? strip and build into control cabinet? Leave as-is and stick it somewhere :)

Looks like the main cab will have to be cut and fabricated as it needs to be pretty big to fit all the bits in and big cabs cost ££££. Also sketching up ideas for the operator panel, probably suspended from the side of the main body somewhere so i still have the ability to use both ends of the ram if needed.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 26, 2016, 04:36:47 PM
Just whatever the drives max input current  is I suppose, not sure if the manual says or not?


I like to have my motherboards in the control panel as it means keyboard and monitor leads are short. On the Chiron I also had the MPG module there so that the buttons, switches and pots had short wiring and I only had to run the CanBus cable back to the IP-A in the electrical cabinet.

If your cabinet is on the side of the mill then possibly have an arm coming from it.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 26, 2016, 04:58:28 PM
Can't see a max current listed, hence the question ;)

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 26, 2016, 05:23:12 PM
Well the AB DSD drives say nominal current for 0.5Kw drive is 5amp and for 1 Kw is 9amp, so probably somewhere in between.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on May 26, 2016, 06:52:13 PM
I used 6A type B circuit breakers for my servos, however I've got no idea where I got that spec from.

Just had a look in the manual, and it says 15A fuse for 750W motors, however the drive input current is listed as 5.5A (largest motor the drives will do is 750W). I'm guessing the fuse rating is for a quick blow (standard) fuse to give a bit surge tolerance, which normal circuit breakers will give anyway.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 27, 2016, 02:11:43 AM
Ok, thanks, 6A B type should do it then.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 27, 2016, 04:15:35 AM
Sketching out my wiring diagram,

Safety:-

A - Use the CSMIO HV O/p to control power to the drives - this drops out when Mach goes into reset
B - Have a totally separate safety circuit with main reset button which drops out power to the drives - this circuit would control Machs' E-Stop system

A would have the drives killed every time Mach went into reset - limits etc
B would only kill the drives if an E-Stop button was pressed - a genuine E-Stop situation

Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on May 27, 2016, 05:03:03 AM
you should have it drop the power to the controller killing the power to the motor may course back current
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 27, 2016, 05:06:50 AM
Explain please, my terminology....

Controller - CSMIO
Drive - the servo amplifier units
Motor - the servo motor itself
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 27, 2016, 05:13:25 AM
Lets re-visit this nugget while i'm planning wiring stuff...


I want/need two spindles here - the main mill quill and a bolt on high speed one - this will be clamped to the main mill quill for starters. Yes it will reduce the Z travel a bit but lets see how it plays before version 2. The aux spindle will only be doing thin stuff and engraving etc so smaller Z travel is probably not an issue.

Obviously when i clamp on the aux spindle it will stop the main Z home functioning so i need two Z homes, maybe two Z++ limits as well?

Ideas -
Two Mach profiles will work - The speed setup will be different for each motor, as will offsets probably and other stuff.
A switch for spindle 1 / spindle 2 - changes limits, motor control, vfd power, vfd control lines etc.?

Will only ever use one spindle or the other. I can definitely see two profiles being needed.

Looking for ways to switch all the lines needed -

Vfd supplies
vfd control and fault lines
vfd speed lines
limit switches for Z axis in two positions
homing for z axis in two positions

probably others....

The programming for the CSMIO plugin I hope will be specific to each profile?

This is a big part of the job - I need two spindles. Control is the issue i think - switching the system from one to the other. No problem doing a cold-start for the changeover - it's a boot-up decision.

Maybe choosing the Mach profile can control the spindle choice?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on May 27, 2016, 06:22:51 AM
E-stops can be a pain to implement.

I opt for limits forming part of the physical E-stop circuit, so if that circuit gets broken, the main power to the drives/spindle/anything else mains powered i.e. coolant pump gets removed.
I then have the KFlop monitoring the e-stop, and should it get triggered, it activates inputs to the drives that trigger them to stop. However, the KFlop has the benefit of being programmed to do this within milliseconds, so it's not reliant on asking the computer/mach what to do.

I know Hood likes to use Safety Relays, that when triggered, will trigger the stop input on drives, then after a small time delay kill all power. This has the benefit the servo drives should remain powered long enough to do a fast controller stop, before power is removed.

I suspect the issue dude1 is trying to mention, is the feature of DC powered drives where they dump excess power back into the DC supply during heavy deceleration, which can cause a voltage spike resulting in over-voltage damage. This doesn't apply to the type of servo drives you're using (it would apply to regenerative drives), but it could cause the drive to trip out with a DC-bus overvoltage error, as they do dump power back into the internal capacitors. If the error did get triggered, all that should happen, is the drive will error out and let the servo freewheel to a stop.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 27, 2016, 06:34:50 AM
Ok so the limit chain is N/C and part of the hold-in circuit for the contactor that feeds the main drive, servo drives, coolant, but not the CSMIO and control circuit PSU's. This contactor would have a set of contacts connected to the limits input on the CSMIO to feed back an E-Stop situation..

One issue i can see is that there will be a massive inrush when pressing the reset button as it will be bringing in three servo drives and a VFD in one go - certain to pop breakers i think.

May need a timed start-up?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on May 27, 2016, 06:49:23 AM
yes
yes
yes

correct
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on May 27, 2016, 06:54:45 AM
I've never had any issue with inrush currents, but you won't know until you try.

Drives/VFDs get powered up when the e-stop circuit is completed and power applied, which is when you're likely to have any surge problems as the internal capacitor banks get charged.
Drives shouldn't be activated until you hit reset, and the VFD should only get activated when you finally turn the spindle one, so everything after the initial power up should be fine.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on May 27, 2016, 07:07:51 AM
nc same here but was told off for killing the power to the drivers and the controller, the bob I use and drivers both have a enable so killing that was what I was told was safer, no inrush, no signal no motion.

everyone has different ideas

Explain please, my terminology....

Controller - CSMIO  yes
Drive - the servo amplifier units  yes 
Motor - the servo motor itself   yes
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on May 27, 2016, 07:17:19 AM
There should be no need to kill power to the controller.

Under normal use, the E-stop circuit should always be live, as it should only be activated as a last resort. During normal use, Mach should only be disabling the drives when entering reset.
Continually cycling the power to drives/VFDs can damage them, but that should never happen under normal circumstances. If it is, then you have a problem.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on May 27, 2016, 07:21:15 AM
the enable not the power if i turn the bob of it turns the driver enable off, it's probley wrong, I have had some bad advice in the past any way I like hoods idea
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 27, 2016, 07:28:07 AM
Ok so we'll try all-on in one go - drives and vfd.

yes e-stop circuit always live.

The e-stop circuit is activated by pressing a "Reset" button, this circuit is held in by a loop consisting of as many red e-stop buttons as needed plus the axis limits. Any limit hit or e-stop mushroom pressed would drop the circuit out and disconnect power to the drives and vfd only AS WELL as telling CSMIO that a limit has been hit.

The e-stop would have to be in a run condition BEFORE mach could come out of reset due to the limit input being down until in a safe condition.

Sound ok?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 27, 2016, 09:53:33 AM
Back to the OP Panel buttons...

I have ...
cycle start
feed hold
cycle stop
spindle FWD (manual)
spindle REV (manual)
spindle OFF (manual)
coolant AUTO / OFF / MANUAL
SAFETY RESET
PC POWER
FRO knob
SPO knob

Jog wheel will be remote pendant type with axis select and multiplier ratio built in.

Now, bearing in mind I have the keyboard and track-ball, should I leave REF-ALL and AXIS DRO ZERO options to the screen for safety or should they have physical buttons?

For Z axis touch-off I would guess a touch-plate etc would be in use so I'm fairly certain a Z-Ref physical button would be good?

Any more
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 27, 2016, 03:04:37 PM
On my machines mains is supplied to the computer power supply. The computer is started and its power supply operates a relays coil. This relays coil operates the 240v coil of a contactor which powers the 24v PSUs which in turn powers the servos logic and the CSMIO.
 I then have a combined Start/Stop button which powers the 24v coil of a contactor which supplies the power stage of my servo drives. This button also supplies 24v to a safety relay.
 The E-Stop string is via this safety relay, it consists of an E-Stop button, limit switches and a NC relay controlled by fault signals from my servo drives.

 The relay contacts on the safety relay  handles such things as enables to drives (via Mach/CSMIO) , Halt signals,  E-Stop to CSMIO ETC.

If a limit is hit or the E-Stop button or indeed a drive faults the relay will take away the halt signals from my drives and they will do a controlled stop, it will tell the CSMIO there is an E-Stop and a fraction of a second later the Enables are taken away from the servo drives.

The CSMIO is always powered as long as the computer is on.

The logic of the servo drives is always powered as long as the computer is on.

The power stage of the servos and the safety relay are powered when I press the start button.

Enables are via Mach to safety relay and can only get to the drive if there is no E-Stop condition or faults on any drives and Mach can not be taken out of Reset under the same circumstances.

There are additional fault signals from the servo drives which go to the CSMIOs integral Servo Fault inputs.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 27, 2016, 03:07:00 PM
I like physical buttons for RefAll but don't bother with Zero Axes.
I also have physical buttons to Reset Servo drives if they fault.

Not sure why you have spindle buttons that are manual, by that I am presuming you are not going to control the spindle via the CSMIO?

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 27, 2016, 03:13:48 PM
I gather you are using different drives than mine - these only have a power input not split logic and power supply, killing the supply kills the whole drive unit.

Seems there are may ways to squints cat - I will go with something that disconnects all the dangerous bits.

In theory just removing the enable signals would halt the drives and VFD, are drive runaways common?
I would not go with a system this weak but in theory it should stop the danger.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 27, 2016, 03:15:29 PM
I like physical buttons for RefAll but don't bother with Zero Axes.
I also have physical buttons to Reset Servo drives if they fault.

Not sure why you have spindle buttons that are manual, by that I am presuming you are not going to control the spindle via the CSMIO?

Hood

My thoughts were that it would retain the manual side of the machine if wanted.

What about Z ref - top of material ?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 27, 2016, 03:35:38 PM
Yes just removing the Enables should stop the axes, they will coast rather than stop but as a BP has a fair amount of friction it will stop quick anyway.

I honestly do not think you will ever use the Bridgeport manually but you never know ;)

I don't use any touch off operations, all manual with a 3D Taster which is set as tool 100 but if you have automated touch off then a button would probably work fine.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 27, 2016, 03:54:26 PM
Of course, i guess i could just MDI an M03 or M04 :)

Care to elaborate on your touch-off?

I'm only going on my minor experience with the 2010 screen-set which has an excellent macro for TOM setting, I cant use the semi-auto tool-change macro as there is nowhere to put a fixed sensing plate.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 27, 2016, 04:44:54 PM
I just have a 3D Taster for top/edge finding and aligning vices etc, well worth the money IMO, especially at the price WNT sell them for.

I have it set via my tool height setter and stored as T100 in the tool table. If I put it in the spindle and call G43H100 then when I bring it down and  it zeroes on the surface I set zero in the Z DRO and then all tools in the changer will be spot on for the Z.

Here is the 3D Taster just in case you are unsure what it is.
https://www.youtube.com/watch?v=7jpnjLVKZN4

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 27, 2016, 04:47:46 PM
Ah Ok are you meaning manual as in switching the spindle on/off etc from a button but still being controlled via the CSMIO?
If so then yes, a button for that is nice. I just have one button as I never need M4 other than when rigid tapping and when doing that it is automatic anyway.
So I just use the OEM code for spindle toggle for my button, that way I just need one button to switch on or off.


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 27, 2016, 04:59:20 PM
Ah Ok are you meaning manual as in switching the spindle on/off etc from a button but still being controlled via the CSMIO?
If so then yes, a button for that is nice. I just have one button as I never need M4 other than when rigid tapping and when doing that it is automatic anyway.
So I just use the OEM code for spindle toggle for my button, that way I just need one button to switch on or off.


Hood

That was the idea but i like the single button toggle better ;)
I dont do rigid tapping as i use a tapping head.

That tool-changer is insane - a work of art :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 27, 2016, 05:26:58 PM
Yes I still love watching the tool changer, must have been amazing to see 30 years ago when most tool changers were taking upwards of 20 seconds for a tool change, the Chirons could do it in under 1 second.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 28, 2016, 03:29:07 AM
Whats the actuating system - air cylinder?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on May 28, 2016, 03:59:07 AM
Yes, 15 cylinders in total if you include the drawbar release.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 02, 2016, 03:24:47 AM
Panel buttons I have ...
cycle start
feed hold
cycle stop
spindle toggle (manual)
coolant AUTO / OFF / MANUAL
SAFETY RESET
PC POWER
FRO knob
SPO knob

Jog wheel will be remote pendant type with axis select and multiplier ratio built in.

Now, bearing in mind I have the keyboard and track-ball, should I leave REF-ALL and AXIS DRO ZERO options to the screen for safety or should they have physical buttons?

For Z axis touch-off I would guess a touch-plate etc would be in use so I'm fairly certain a Z-Ref physical button would be good - I only have R8 tooling so getting preset tool heights is going to be a bit of a kludge. Z ref will need doing every tool-change.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on June 02, 2016, 03:33:25 AM
add the tool height to your pendent as well, it makes life very easy being able to be right there. ones you use pendents you love them
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 02, 2016, 03:34:31 AM
Still working on the dual-spindle setup...

I need two spindles - the main mill quill (slow/heavy) and a bolt on one (fast/light) - this will be clamped to the main mill quill for starters. Yes it will reduce the Z travel a bit but lets see how it plays before version 2. The aux spindle will only be doing thin stuff and engraving etc so smaller Z travel is probably not an issue.

Obviously when i clamp on the aux spindle it will stop the main Z home functioning so i need two Z homes, maybe two Z++ limits as well?

Ideas -

Two Mach profiles will work - The speed setup will be different for each motor, as will offsets probably and other stuff.

Choosing the Mach profile controls the system - spindle 1 / spindle 2 - an output activated only in one profile will operate a relay that changes Z limits, vfd power, vfd control lines etc.

Will only ever use one spindle or the other, restarting to change over is not an issue.

Looking for ways to switch all the lines needed -

Vfd supplies - contactor?
vfd control and fault lines - changeover relay?
vfd speed lines - changeover relay?
Home/limit switches for Z axis in two positions - changeover relay?

probably others?

The programming for the CSMIO plugin I hope will be specific to each profile, will test this today.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 02, 2016, 03:35:23 AM
add the tool height to your pendent as well, it makes life very easy being able to be right there. ones you use pendents you love them

It's a pre-built unit, doubtful if there are spare lines in the cable but will check.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 02, 2016, 04:06:16 AM
Ok, the good news is that the CSMIO plugin setup IS specific to the Mach profile in use.

But, I need an output that energises as soon as Mach is started - an output that comes on when out of reset won't work as the signals will be in the wrong state to allow Mach to come out of reset - catch 22.

Is there an output that I can get which will allow me to control a relay as soon as Mach is loaded?

A hard change-over switch is the next option but that is risky as changing it accidentally while Mach is on will probably cause havoc.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 02, 2016, 06:19:22 AM
Not even sure if it would work with the CSMIO but maybe you could utilise  the chargepump if it does?

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 02, 2016, 06:43:13 AM
Seems not, no mention of charge pump in manual :(

Any other options?

It really needs some sort of interlocked changeover.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 02, 2016, 07:47:58 AM
I don't need to mess with switching homes/vfd signals etc - the wonderful CSMIO has so much I/O that i can connect both systems at once and use the different Mach profiles to do the control. :) It has two 0-10v outputs for the spindle motors, most of the functions can be duplicated, just the Z-home switch, 0-10v and the Run Fwd need their own outputs.

Nice.

Also, as we don't need to switch control lines now, I think the spindle VFD required can be controlled via its own output using the HV output in CSMIO and a small contactor/relay combo.

Even nicer :)

So startup will be just a matter of choosing the right shortcut for Mach to launch and let the machine get on with the settings while i fit or remove the high-speed spindle.

One little hiccup to my smoothness here is that the spindle needs to be parked in a position low enough to enable the aux spindle to be fitted before OR it means starting one profile then lowering the spindle then closing and starting the aux profile - not as smooth;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 03, 2016, 03:30:16 AM
Sorted it out :)

Just use an output in Mach for each profile - active low, no other use. It comes on as soon as Mach loads and stays on regardless of reset state etc - this output can then control the respective contactor for the VFD needed for that profile.

The supplies will also go through the E-Stop system but this means that the whole startup is now just a matter of clicking on the correct Mach profile :)

Now, lets look at the Z axis...

I am intending to bolt the aux spindle onto the main quill shaft, this means that my Z travel will be reduced but not drastically i think.

It also means I need two Z home positions - can I use ONE Z home switch at the lower position and use the Z home-offset to tell the system where the home is respective to the profile in use??

Questions-

If i have one home switch in the lower position and the head is already above that switch, what happens when i ref-all??

Is there a smart fix for Z upper limit switch or do I have to try and fit TWO limits switches in at the top??

Getting there :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 03, 2016, 03:41:12 AM
Hmm, bench-top tests seem to look promising - with a home switch offset of 50mm, when i do a ref-all it moves to the switch, stops, moves off, then reverses 50mm. I think that is just what it needs ?

If the switch is already closed when ref-all is called, it just backs off slowly until it opens - nice, BUT the switch trigger MUST be continuous and not just a passing trigger so a long switch cam will be needed there.

Limits??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 03, 2016, 06:48:10 AM
Rough draft of power wiring and e-stop circuit...

Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on June 03, 2016, 10:42:37 AM
Couple things from a quick look at the diagram, you'll need a limit override switch, and do you really need to have the power for each servo drive use a separate contact?
The same could be said about the ESR relay.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 03, 2016, 10:51:09 AM
Ooh, good point re the override switch, forgot about that one :)

No real reason for the multiple ESR, just  the way it evolved, will alter that one.

No harm in having the drives on multiple contacts, its a common style of contactor so no need to combine.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 03, 2016, 01:17:33 PM
you'll need a limit override switch,

Hmm, thinking on the drive home  ;), I can see one reason when that would be needed - if the soft-limits fail and the Z axis rams the head right up or down - there is no hand wheel on the Z axis so no way to get it back down again, although I could simply reach up and spin the pulley by hand.

But apart from that, if the X or Y axis runs off the end then they can be rewound before pressing reset?

An E-stop loop would not be bypassed by the limits override so thats ok.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on June 03, 2016, 03:24:07 PM
You do have the benefit of being able to move things manually, so you could probably manage without an override button.

I think it would probably be a good idea to wire up your control box to allow for the possibility of adding one later though. Have the limit switch loop come back to a terminal in the control box, before connecting to the E-stop loop, so if you do need to add one later, you've got a nice convenient point to wire one in, with minimal rewiring needed.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 03, 2016, 03:29:51 PM
Yes i like to wire that way anyway, makes things much easier to trace issues later on when the external stuff comes in on a terminal strip, one by one, no hidden loops etc.

I would like to think that once homing and safe-limits is up and running the only time the hard limits would be it is after a runaway drive and I've not heard of that yet;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 05, 2016, 11:31:16 AM
Problem with having lost of I/O available is you soon find things to do with it and end up with one short :D

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 05, 2016, 11:33:35 AM
I have a bit more on the MPG module ;)

My list is only about half-capacity at present, plenty to play with :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 05, 2016, 11:37:11 AM
I think I have about 3 or 4 digital I/O's  spare on the plasma and I too have the MPG module and the IP-S has more than the IP-A.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 05, 2016, 11:42:37 AM
I must have missed some bells and whistles then ;)

I even have it controlling the lamps on the buttons so that the OFF, FEED-HOLD ETC only come on when code is running etc

Having the limits on the power side rather than the control side also saved inputs.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 05, 2016, 05:16:27 PM
No limits via the IP-S either, all hardware and only an E-Stop input.

Just looked and I am using the following I/O (so far)

For outputs I have
Enables for X, Y and Z and just doubled up slave with Y. I could have used one enable for the lot but using three or more reduces the Inrush as there is a delay between enables specifically for that purpose.

I have Fault Reset  buttons for X Y Z and again just shared slave with Y.

I have a Home Z output but that was for the current sensing method so I will not be using that now

I have the Solenoid for the cylinder.

I have 3 used for the THC and may use another for the C Axis protocol if I think it will be worth it.

So all in all I  am using 10 of the 16 outputs but as said could easily free up more if required by using the one enable and even the one reset.


Inputs

I have Z at Home, this again is not used now as it was for the current sensing homing. I am not sure if the cylinder for the touch off I am using has magnets inside, if it does then I will likely fit a reed switch for added safety when probing, so would use this input.

I have X Y Z and Slave  fault signals

X Y Z and Slave Index Inputs (not needed on IP-A as it already has Index Inputs)

E-Stop input

3 THC Inputs

M31 Limit switch input

I have 9 switch inputs

Input for the torch breakaway prox sensor

X Y Z and Slave Home switch Inputs

So 28 out of the 32 Inputs used so far.


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 06, 2016, 02:14:43 AM
Of course, its a plasma not mill ;)

So far I have..

Analogues - feed rate override, speed override, vfd1 speed, vfd 2 speed

Digitals ins...
Servo x fault
servo y fault
servo z fault
cycle start
feed hold
stop
E-stop signal
Probe
spindle toggle
Ref Z axis
Home X*
Home Y*
Home Z*
VFD 1/2 fault

*these will likely be left as screen clicks as only used once per session

Digital outputs...
Servos enable
servo's reset
spindle fwd
spindle rev
coolant
relay for button lamps
spindle 2 fwd
vfd 1 select
vfd 2 select

:)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 06, 2016, 09:22:05 AM
Revised the safety wiring a little, added some fuses and changed a multiple relay for a single one.

Also sketched up my panel button wiring, the idea is to have the "RUN" relay controlled via a brain or something so it switches as soon as Mach comes out of stop condition i.e. running code or in feed hold - I presume there is a smart way of doing this :)

This relay then controls the supply to the respective buttons and button LEDS - the idea here was that when in stop mode, you can only press the start, ref z and spindle toggle buttons, as soon as you press the start button, the logic changes so that only the stop and feed-hold buttons are active.

NOW, my query here is - is it wise to control the supply to the switches AS WELL as the LEDs or leave the switches permanently live but control the supply to the LEDs only?

Thoughts??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 07, 2016, 07:56:18 AM
Pendant turned up today - if anyone is looking for one, this is the first time i have got something from China on eBay and have been surprised at  the quality of it :)

http://www.ebay.co.uk/itm/251989254779?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

It actually 'feels' good - nice clean clicks on the wheel, positive switches, heavy case and a hard wearing cable, will have to lash it up to my test rig and have a play with it ;)

Away for two weeks on thursday so it'll have to wait i think.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 08, 2016, 04:00:08 AM
Pendant works perfectly - also has on-off switch so the keyboard jog can still be used :)

I think thats about it for a couple of weeks now as i'm off on holiday tomorrow :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 24, 2016, 11:32:15 AM
Hi all, back again :)

Wasted no time in getting out to the shop, started catching up on customer orders and did some work on the mill.

Seems I have ordered a screw set for the Z axis that is far too long - bum!
Will eBay that one for a few quid - its a 1605 zero backlash unit 360mm long if anyone wants it.

Then i discovered the motor bearings are half-shot, a bit of slack and grumble when spun. It will work ok but not sure having come this far if i should refit or replace with something else - options would be repair, fit a new vfd style motor with shaft extended or throw on a servo motor.

Views?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 24, 2016, 02:58:41 PM
You not just chop it down in length?


Wont tell you the way I would go re the spindle, you will already know :D

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 24, 2016, 03:07:10 PM
Hiya Hood,

I'm not 100% certain now, I won't be doing anything until I have the frame for the Z axis machined up and assembled, it might just be that it "seems" too big at present, time will tell on that one.

I can't re-read the whole thread but my guess is you would throw in a servo and go direct drive?

As for the X & Y motor support plates, what thickness ally here - 10mm, 12mm, 15mm ??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 24, 2016, 03:46:29 PM
From a quick scan back through the thread it seems a 1.8kw 3000rpm AC servo at 1:1 drive should be ok if i keep back-gear.

Its about £350 so not too bad.

Larger ones may be better but then top speed seems to drop to 2500rpm or 2000rpm so would need a ratio increase.

I have a feeling based on usage that it really does not need max spindle power at all.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 24, 2016, 04:25:10 PM
I used steel for my brackets on the manual mill conversion, 10mm I think.
With Alu  I think if doing a long Y bracket like I did I would go 12mm, X would likely be fine in 10mm.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 24, 2016, 04:34:07 PM
Ok, great, i'll likely use 12mm ally then as its a good size for counter-boring bolt heads etc. The Y bracket I am sketching up at about 350mm long with the motor beneath the knee at about 5 o'clock angle.

The X axis will likely be towards the rear or below but the motor will probably have to stick out the end as most do due to it's size, this makes mounting harder but will not fit under the table as it hits the knee.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 25, 2016, 08:15:15 AM
Well i spent a few hours trying to dismantle the motor this morning but could not even get the drive disc off the end so i don't think bearing replacement is on.

It's a toss-up between living with a grumbly motor or throwing one of these in...

http://www.aliexpress.com/store/product/NEW-1-8kw-AC-Servo-Motor-and-Drive-in-6N-M-1800W-3000RPM-with-Servo-Cable/314742_2037588952.html

A 2kw would be better but none listed at present.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 25, 2016, 11:52:50 AM
I think 44 tooth HTD8 pitch x 30mm wide belt & pulleys will handle this ok.

Decided to go full servo - budget was busted long ago so might as well carry on and fracture it some more :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 26, 2016, 04:41:51 AM
Can't recall what pulleys I have on the Beaver but the belt is 25 wide 8mm pitch. In fact even on the big lathe it is just 25mm wide and 8mm pitch and it has peak torque of over 150Nm and has run fine for probably 5 or 6 years. They both use Gates GT3 belts though which are supposed to be a bit tougher.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 26, 2016, 05:52:23 AM
Ok thanks, it makes little difference here as plenty of room in head for any width of belt, will check options before ordering.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 26, 2016, 06:21:55 AM
Just looked in my BSL book and I am using 20mm wide belts on the Beaver, the Computurn and also on the manual lathe that I fitted a servo spindle to.
The Gates programme is pretty good for seeing what will work for different variables, it also gives you belt lengths and pulley sizes from the data you input, very handy wee programme indeed :)


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 26, 2016, 09:05:23 AM
Had a chunk of 15mm plate laying about and decided to exercise my minimal CAD/CAM knowledge so made the Y axis motor mount plate.

Most impressed when it actually fitted 100% as intended :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 26, 2016, 01:40:09 PM
Looking good :)
BTW just sent you a PM.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 27, 2016, 05:36:25 AM
Doubts creeping back in again on the spindle motor - 1.8kw servo seems to be the biggest i can get that runs at 3000rpm, but is it big enough? The 1.5Hp motor is 1.2kW so I was guessing at its minimum mechanical speed of 2:1 on the reeves drive it would be equivalent to 2.4kW as its about a 2:1 or 1:2 speed range on the 1440rpm motor.

However, the drive itself takes a fair lump of that power as they are not  that efficient.

So the options are still the same - build around the std motor / vfd and have possibly very vague speed settings, or throw in the 1.8kW servo and suck-it-and-see.

I guess a servo just bogs down until the drive trips on over-current if the spindle is pushed too hard????
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 27, 2016, 05:52:30 AM
Yes , assuming you have the fault signal going to the IP-A, either directly of via and E-Stop string or whatever, then the motion would stop when that happens.

Think probably I would go with the standard motor for now and see how things are. Keep an eye out on eBay for a bigger drive/motor later if you need to.
BTW I forgot you do not have 3 phase so the one I  mentioned wouldn't do anyway.

There are often drives on that would drive that motor I linked to but prices vary and are often crazy which makes the Chinese ones look good.
Sad thing about the Chinese motors/drives though, is as you have found out, the limited top speed.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 27, 2016, 05:53:18 AM
From what data I can find, a dual-cone Reeves drive is about 77% efficient so I only really have about 1.15Hp anyway which is 0.86kW, so at min speed its around 1.72kW and at top speed around 0.43kW, this is ignoring all other losses of course - spindle bearings etc.

So, maybe a 1.8kW servo would be pretty well suited to this job after all??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 27, 2016, 05:56:07 AM
Not sure where you are getting the change in KW from, if the original motor via the pulleys then it will be constant power no matter the spindle rpm as the motor is always at rated speed and as such KW is always at rated speed.
The Torque however will vary with the gearing.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 27, 2016, 06:48:54 AM
Ah bum, the dreaded torque/Hp confusion again :(

So I have 1.5Hp regardless (fixed speed motor), at 1:1 speed setting the spindle will only see 1.15Hp though due to the transmission efficiency?

Thats how i figured it - i'm still wrong though?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 27, 2016, 07:07:48 AM
Aye, used to confuse me as well, took awhile to get through the bald heid :)

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 27, 2016, 07:43:16 AM
So, what i'm really saying or asking is:-

I have a 1.2kW fixed speed motor connected to a transmission of 77% efficiency with a ratio range of 2:1 to 1:2

Can I replace that with a variable speed 1.8kW AC servo and high efficiency drive (toothed belt is around 98%) ??

And of course, will it work??

I will be keeping the back-gear for low speed / high torque stuff in the 40-400rpm range as now.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 27, 2016, 01:43:03 PM
Well the induction motor would have (basing torque on 1.2Kw)

2880RPM  0.8kW and  3.94 Nm

1440RPM   0.8Kw and  7.9 Nm

720 RPM    0.8Kw and  15.78Nm

The Servo would have

3000RPM  1.8kW and  5.7Nm

1500RPM   0.9Kw and  5.7 Nm

750 RPM    0.45Kw and 5.7Nm

So I suppose the way to see would be to look up some charts to see what the torque and hp requirements would be for the type of tools and materials you would be using.
 Personally I think the power drop off of the 1.8Kw servo may just be too much.


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 27, 2016, 01:56:59 PM
Thanks Hood, that explains it nicely, seems I would need to go 3.8kW / 15Nm to get equivalent performance - that is not only too expensive but a lot more power needed PLUS its only 2500rpm.

That has made my mind up to refit the existing motor and run until it fails totally, speed control will likely be a bit hoo-ha but I doubt it will hurt.

The encoder module would have been a ball-ache to fit anyway, I wrongly presumed it uses the motor encoder signals but fitting a shaft encoder would be pretty hard on a Bridgeport.

Enough of this nonsense :)

One day the damn replacement Y axis screw will turn up and i'll be able to start moving ahead again, it's stuck in the post somewhere :(
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on June 27, 2016, 02:04:47 PM
I just use the motors encoder, well actually the interpolated/simulated output from the drive as the encoder itself is sine/cosine. As long as it is 1:1 it is fine. Not sure about the Chinese drives but most I have used have the option to divide or multiply the physical encoders counts for the drives outputs, I did that on the wee lathe and threading worked fine, never tried rigid tapping on it though I think it would have been fine as well.
All I do is have the encoder input on the IP-A jumpered across to the Enc module.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 27, 2016, 02:21:57 PM

All I do is have the encoder input on the IP-A jumpered across to the Enc module.

Hood

THAT explains a lot, thanks, did not know you can do that :)

Academic though as some of the figures I'm looking at for power required really do need all the clout i can get so wouldn't want to fit a weaker solution. It explains why she used to get warm on a busy day ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 29, 2016, 02:10:14 PM
Finally got the replacement Y axis screw today,

Got the table on, nice silky smooth motion :)

Should be able to start moving forwards again now.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 02, 2016, 10:32:58 AM
Got X-axis motor plate fully fitted...

Limit switches next, Y-Axis Limits and home switches...
From the left we have Y--, Y-Home, Y++.
The home switch remains tripped once it trips so that i can home even if the switch is triggered, a home-offset value will take care of the switch position.

Then the X-axis, a bit harder this one, first idea...
From the right we have X-home then a dual-direction X-- & X++ switch. The picture is not quite right - imagine the right-hand switch is another roller type like the left one, I have one somewhere, just got to find it ;)

The only down-side I can see is that it blocks the chances of using flood coolant again as the switches are in the way of the left drain hole.

Still thinking on this one.

Lost motion - is zero lost motion possible? never used a ball-screw machine. If i mount an indicator on the table, i can turn the Y-axis motor pulley about 1-1/2mm before the table starts to move. In terms of a Bridgeport thats really tight, the old screws had about half a turn of slop ;) but should it be tighter?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 02, 2016, 01:42:58 PM
I would have used only two switches on each axis, one for home the other limit.
You can do that if you put the switches on the moving part of the axis and have the triggers either end. You can stack the switches on top of each other so that you can have the triggers stacked.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 02, 2016, 01:51:00 PM
Yes, it just seemed better on the Y axis to run 3 switches, on the X axis i do only have the two. ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 03, 2016, 12:55:10 PM
I hooked the rebuilt head up to my VFD today, sounds a hell of a lot better (thanks for the bits Hood) for some unknown reason it runs a bit warm around the top bearing plate though.

Its not quite right though as the vari-speed system seems to do nothing in the higher end when in back-gear, but is ok in normal gear??

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 04, 2016, 02:48:54 PM
Don't know how that could be, long time since I looked at a BP but the vari pulleys should be first in line after the motor whether in main or back gear so speed should vary when you move them.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 04, 2016, 03:01:28 PM
Thats what i was looking at last night in the parts book, the vari-speed shaft does not move with back-gear, it's fixed so I am unsure of whats going on there, will need to mess about with it some more. I can't see any way it can be put back together wrong so that it works in high but not low - very odd indeed.

The metal came today for the X axis motor mount - once i get that cut and fitted up i can do a lash-up on the bench and get the motors powered up for a preliminary motion test :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 05, 2016, 06:00:13 AM
Just refreshing my mind with a study of my wiring diagrams etc and the e-stop system looked like it needs verifying ;)

I currently have the e-stop buttons and limit switches in a loop that controls a relay that controls mains power to each of the drives and vcd's, it also supplies a signal to Mach3 via the CSMIO

Is that a good idea?

My main concern is removing power to a drive that is running may or may not be a good idea.

Or is it sufficient to simply remove the Enable signals - this does not protect from a faulty or runaway drive (busted encoder?)

Sanity check really. ;)

Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on July 05, 2016, 06:43:26 PM
Ideally you want the drive to stop before removing power, however anything that relies on AC power to power it, should not have any issues with the power being cut cleanly.

The worst that should happen, is the drive enters fault mode when it detects the internal DC bus voltage has dropped below the minimum voltage.

Power being removed while the drive is under hard deceleration would be no different to the drive still being powered. If things decelerate too fast, with too much energy being dumped back in to the internal DC supply, the drive will fault out due to the internal DC bus voltage rising too high, at which point the drive will normally fault out and let the servo freewheel to a halt. This is where external braking resistors come in, as it allows the drive to dump more energy, and avoid triggering over voltage errors.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 06, 2016, 02:18:29 AM
Hmm, ok so it may be a reasonable plan then, the e-stop also tells the CSMIO and therefore Mach3 that there is a fault so it sort of will remove the drive signal as well, but that all relies on the speed of signal transmission etc from the e-stop input to the CSMIO to Mach then back to the CSMIO and then to the drive itself.

I could easily wire the "Enable" lines through the safety circuit so they are cut the same instant that the power goes down?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 06, 2016, 02:06:12 PM
Nearly there with the X axis motor mount, once thats done I can lash-up the drives and do a motion test :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 07, 2016, 10:58:27 AM
Whats everyone using as a control cabinet?

Needs to be fairly large and deep as servo drives are pretty deep, commercial control cabs are very ££££ in large sizes. I could weld something up but would not look too professional i think, also been looking at steel tool cabinets which come with doors etc :)

any other ideas ?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 09, 2016, 07:15:06 AM
We have motion, on one axis at least :)

Threw it all together on the bench and fired her up. I can jog and do a home run, did an auto-pid tune and the error is around 150 now.

Ok, issues to sort....

I can't do an MDI for some reason - nothing happens at all.
When i press Reset in Mach I get a message telling me to check encoder connections as there was an error - if i ok the message it all seems to work ok??
There is a vibration in the drive at lower speeds, pretty violent and would certainly show up in the cut.
7500mm/min is frighteningly fast, I have lowered it to 5000 for testing.

Anyone care to wade in with some suggestions??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 09, 2016, 07:38:25 AM
Hmm, ok i can now do MDI BUT....

The DRO's in Mach are backwards ?

If i jog left the table moves left but the DRO goes negative?

I tried the "Reverse" option in homing but then the jog buttons are reversed?

Anyone?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 09, 2016, 09:49:30 AM
Ok, learning all the time ;)

A friend has just advised me that i have gone the wrong way and fallen head-first into the gantry mill vs knee mill trap big-time.

I was setting up so that jogging left moved the table left - this is wrong and it seems i need to start thinking of the tool NOT the table, so as i have it now, jogging left will send the tool off to the right.

I can see this is going to be a bugger to get my head round ;)

I also had homing wrong - i was thinking of the table in the bottom-left corner but in reality from the TOOL point of view, that is X- and Y+ NOT X- & Y- so when homed the table will be away from me and to the right.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 09, 2016, 01:32:53 PM
Homing can be any place you like for example on a knee mill it is often advantageous to home with the Y fully positive (table at front) so that loading the work is easier.
The CSMIO have an option in their plugin so you can set the Home Off value as legacy. What that means is if you home fully positive then you can enter the distance that you are away from Machine zero and when you home it will read that distance rather than zero. The place you enter that value is Homing and Limits and it is in the Home Off box.

The default way for Home Off with the CS-Lab products is that the Home Off value actually moves the axis that distance after it homes, it was  for a long time the only way to set it up and was a PITA for quite a few of us as we wanted the Home Off to be the way Mach meant it to be (the legacy way ) but thankfully CS-Lab listened and gave us the option :)
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 09, 2016, 02:56:02 PM
Great, i realised i fitted the Y home switch at the wrong end so i set it up to home at the front and then offset to the rear which is really zero, it would be useful not to move the axis though - where is the setting that stops the axis actually moving?

When i press Reset in Mach I get a message telling me to check the encoder connections as there was an error - if i ok the message it all seems to work ok though - any ideas?

I have got rid of the vibration by doing another tuning, its much smoother now, probably too much gain maybe.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 09, 2016, 03:17:35 PM
It is under Special Functions and then Other, should see on right side the Legacy Home Offset option.

Not sure about the encoders,never seen that message. Presume you have double checked all connections and that the IP-A sees the encoder counts correctly?
If you attach your xml I will take a look and see if I can see anything.

Good news on the tuning :)
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 09, 2016, 03:30:50 PM
Great, that will help.

I'll get the xml tomorrow - its out in the shop.

The encoder thing is odd, i've checked the wires, the DRO's behave normally in Mach, no ePid fault messages, i had the setup working on the bench at work and tested all the drives and each motor as well, although not on a machine of course.

Following-error in tuning is still around 400.

There is some backlash/lost motion, about 0.04mm in the Y axis and around 0.15mm in the X but the thrust bearings on that axis need looking at so i'm not too concerned yet.

Edit...

In the CSMIO monitor, the x-axis encoder readout is alternating between a number and a red 255? Distance travelled is spot-on though it seems.

Also, one plus point - homing seems to be stunningly accurate, on my dial indicator it read better than 0.01mm variation. :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 09, 2016, 05:59:19 PM
Ok kind of sounds like there is a problem with your encoder signals. Sure Jonathon (jofriedl) had similar red values and it ended up being poor opto isolation and lots of noise.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 10, 2016, 03:09:28 AM
Ok, i'll try swapping the connections over and see if the fault follows, also check my grounding as it all just thrown together on the bench at present.

If no luck, i'll dig the 'scope out and have a look-see.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 10, 2016, 06:39:17 AM
Hmm, odd - the encoder fault was not there today, maybe a PC reboot or complete shutdown fixed it? Been knocking seven bells out of it all morning and it's not returned so I'm happy with that.

Next I fitted up the Spindle VFD, expecting serious issues with my complex manual/auto speed control idea. I was 100% amazed that I have perfect control of speed from 40rpm to 3000rpm within about 25rpm tolerance! It tells me to choose back-gear or high-gear and high or low speed pulley setting depending on speed chosen.

The only issue it does have is that if it is set for say 100rpm in back-gear low range, and the code calls for 2000rpm in high-gear high range, it will spin up the spindle and then tell me to change gear - this cannot be done without smashing the drive.

I have all the code in SpindleSpeed.m1s - can it also stop the spindle and restart it after pressing enter without wrecking the code flow etc ??

Picture of my bench-mess below ;) Useful to gain an idea of cabinet size too.

A short video here...
https://youtu.be/RiXxmCpC-R0 (https://youtu.be/RiXxmCpC-R0)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 10, 2016, 02:18:52 PM
It is under Special Functions and then Other, should see on right side the Legacy Home Offset option.

Hood

The legacy homing option does not seem to work, I turned it on but although it did stop the axes moving after homing, it also corrupted axis movement in that the Y axis only moved one-way regardless of instruction - the jog buttons only moved one way and the MPG sent it slamming into the stops. Turning the legacy option off again and re-starting Mach fixed the issue.

I'll leave it off for now i think.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 10, 2016, 03:40:05 PM
Good news on the encoder, maybe just noise getting in with the wiring being a bit hairy and maybe the encoder outs on the drives are a bit weak.

Looks like it is running nicely, certainly a lot better than your taste in music  >:D

Legacy homing worksworked fine for me on Chiron, small lathe, plasma, friends Avon mill and others I know that use it.
Couldnt be you had the Home Off value set incorrectly?

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 10, 2016, 03:49:26 PM
Ha, the music was the radio, just fills in the quiet bits ;)

It gives me the impression it might actually work ;)

I had the home offsets set so that in normal mode it worked properly - it homed, then moved to where zero really was.
I just turned on legacy homing and when i tried jogging, it only moved one way, tried the MPG and bang it went, good thing i have the limits wired.
Turn off legacy and back to normal - very odd.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 10, 2016, 03:57:31 PM

So I presume you had a negative value in Home Off if you were homing fully positive?
If so that is likely your problem as when in Legacy mode you enter the value that the axis is away from fully negative.
So say you have 300mm on the Y, you home so the table is towards you (fully positive) you enter 300 into the Home Off and when the machine homes the Y the machine coords are set to 300 rather than Zero, that way Mach knows where the machine zero is.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 10, 2016, 04:07:04 PM
Hmm, i'll have to check/try that i think, not sure what is in there, but it does home at the front (max Y+)

I think it may be negative.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 10, 2016, 04:14:20 PM
To be honest I can't remember how the default (for csmio) home off value works, it was about 3- 4 years ago when I set up the wee lathe with the IP-S so not sure whether it required a +ve or -ve value.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 10, 2016, 04:16:28 PM
I just had it set so that it worked in normal mode then presumed turning on legacy just stopped the axes moving?

Seems not.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 10, 2016, 04:19:46 PM
Yes it does but it sets the Machine coords to the value you have set in Home Off, so if that was the opposite to what it should be it could be the reason things got screwed.
It might not have been the issue , its the only thing I can think of though.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 10, 2016, 04:27:17 PM
Ok, so i am homing at about Y250 due to the switch position, I should stick 250 in home-off and turn on legacy?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 10, 2016, 04:39:58 PM
The way I set things up  is have nothing in Home Off, Soft Limits off, home the machine, switch to machine coords and jog to the fully neg limit switch and note the value, that is what you enter into the Home Off box (well  it will be a negative but you want to put a positive in there). You can then home again and jog to the positive limit and note the value. You can then set that as your Soft limits Max and your soft limits Min will be zero. You should now have it all set up and can again home and switch on Soft Limits and hopefully forget about things :)
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 10, 2016, 04:49:27 PM
I think i see where its going possibly -

1 - in normal mode where the axis moves, I have a negative number in home off as it tells the axis to move negatively or towards home.

2 - in legacy mode where it does not move, I need a positive number as that is where the axis really is.

Pretty certain i have it set as (1) above and i need (2)

;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 10, 2016, 05:23:09 PM
Well that is the only explanation I can think of why Legacy didn't work for you, fingers crossed :)
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 11, 2016, 09:43:01 AM
It works fine now - the numbers do have to be reversed if it was previously set for normal homing.

Negative for home offset with axis motion
positive for home offset with no motion / legacy homing.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 11, 2016, 01:29:46 PM
Glad that was all it was :)
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 12, 2016, 07:48:26 AM
What does one do with the PC?

I had thought of stripping it and building into the moveable pendant type control panel but i have doubts about the life expectancy of the hard-disk?

I could possibly stand it in the bottom of the control cab, this means longer USB and video leads.

Any other ideas or go with one of these??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 12, 2016, 09:40:08 AM
I have my motherboards in the cabinets, on the Chiron it is in the control panel cabinet, plasma it is the main cabinet.
Will post a few pics later if I get a chance.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on July 12, 2016, 01:58:18 PM
You could always fit a SSD if you're worried about hard disk life.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 12, 2016, 02:02:20 PM
You could always fit a SSD if you're worried about hard disk life.

Coincidence - i was just looking into that !
Seems one of these should do it.
https://www.amazon.co.uk/Zheino-Solid-State-Desktop-Laptop/dp/B011KY4XFM/ref=sr_1_50?ie=UTF8&qid=1468332364&sr=8-50&keywords=sata+ssd
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 12, 2016, 02:42:37 PM
I don't think you would have an issue with the HDD, all my machines have them in the main cabinet or the control panel.

Here are a few pics I found, Chiron is the first, mobo HDD, MPG and Extra I/O module etc are in the control panel.
The others are plasma, Bridgeport and Beaver.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 12, 2016, 02:51:20 PM
Nice, thanks for that.

When mounting the MPG module remotely, what sort of cable is used to extend the CANbus?
Is it a serial lead wired 1:1 etc or something exotic?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 12, 2016, 02:57:21 PM
I just used some shielded cable and soldered on DB9 plugs, the manual should give the pinouts but as far as I remember it is just 1:1
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Jim Catnach on July 13, 2016, 08:34:50 PM
Hi - My first post - so this might not be the right place - for which I apologise in advance, so here goes I use an Elliot knee mill daily for work and have slowly converted it to CNC - ball screws one day when mill not used - then X under Mach3 then Y and then the quill - so I could continue to use the mill  partially manually and learn Mach 3 etc as I went along  - this has worked really well as I don't really want the mill for fast  / production type CNC work but for cutting complex curves and similar that manual milling with rotary tables and dividing heads had just become a real pain. For a bit of history /  reasoning behind this I am a self employed engineer who grew up on punch cards, Unix, VB etc and restore vintage cars / manufacture parts so CNC is really a time saving and helpful step forwards for me I simply write the G code into Mach as I go to produce some fantastic parts - leave the machine running and go and make something else on the lathe's whilst I wait for it to complete ! Mach is great for retro fitting a mill and has been done very simply with Nema 34 steppers.

I am now developing a fourth axis for complex cam follower profiles and the like which I have made on a small mill in the past which  I had also converted for 4 axis CNC - so yes by all means retrofit a knee mill but a bed would have been more rigid - the Elliot is much more rigid than a Bridge which gives me great cutting with hard steels and a superb surface finish.

Now a problem has crept in - if I leave the mill standing but all powered up under Mach then the X, Y, X and 4th axis often start counting on their own ! into the millions but none of the axis are moving until I quit Mach then restart, home everything to zero the millions stored and start again - this is now becoming a real pain as I develop the G code as " going along " if it happens at that point all is lost ! Please help me - someone must know what causes this ?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 14, 2016, 02:14:55 AM
Hi Jim, as you guessed its not quite the right place, I would ask a Mod to move your question to a new thread - you will get a better response that way.

I have seen your issue on one of my Mach installs but only after pressing the reset button to put Mach into reset, i did a new install and it seemed to help.

People will need to know your install - Mach version etc to offer help.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 14, 2016, 10:33:59 AM
VFD control ?

I currently have my fwd and rev signals wired through two relays using the built-in VFD control supply to control itself.

Is this worth it or should I bin the relays and connect the VFD ground to the CSMIO control ground and go direct from CSMIO output to VFD input?

Its a little layer of isolation but also mechanical complexity if not needed.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 16, 2016, 11:01:33 AM
Z axis coming along nicely - finally got the parts machined on the mini-mill ;)

Last step will be the link from the Z-nut to the quill.

My first thought was to machine up a lump of steel that will fit round the nut, then weld it to the original BP part - this would make building it simpler as i can fit it up on the mill clamp the tow together and then remove to make the weld.

Maybe plasma-cut the part from 10 or 12mm plate.

Sound like a plan ?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 16, 2016, 01:52:50 PM
VFDs are notoriously noisy especially if it is a Chinese one, so I think I would personally keep the relays.
I machined a part, sort of like a rounded Y shape and just had it bolted into the original hole in the quill, will see if I can find a pic or at least a 3D Image of it and post.


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 16, 2016, 01:58:06 PM
Thanks Hood - these are both good branded name VFD's but i might still keep the relays, no harm in a little extra isolation.

I have a pic that shows a little of your part, my reason joining two was that the original part is a very tight fit and was hoped to give me the most stability at the weakest point.

Still be good to see ideas though.

I will have a play tomorrow with the plasma and see what comes out. I still cant assemble as i don't have a fixed bearing block yet - was sent the wrong one :(
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 17, 2016, 04:16:19 AM
Afraid I have searched and can't find anything, it will be there but finding something so old is a problem.

If your part is solid then what you propose should work fine, if I recall mine was already damaged anyway.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 17, 2016, 04:19:51 AM
No worries, thanks for looking.

I'm hoping to do a mock-up today, need to make sure i don't weld something up that can't be assembled later ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 18, 2016, 08:49:16 AM
Anyone know the oemcode for Spindle on/off toggle function??

Cant find a clear answer in the listings ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 18, 2016, 01:41:13 PM
110
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 18, 2016, 01:56:44 PM
Thanks,

My book lists that as "Spindle CW, reset THC height 110"

A little vague ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 18, 2016, 02:12:40 PM
Yep, lots of things vague like that :D

Easiest way I have found for most things is look at the standard screenset in Screen4 (or MachScreen possibly) and see what oems are used.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 18, 2016, 02:17:03 PM
Good point ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 19, 2016, 01:30:42 PM
The spindle toggle works well :)

Also threw some LED's into my buttons for fun, video here.

https://youtu.be/5Yz0CloE7TA (https://youtu.be/5Yz0CloE7TA)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 20, 2016, 09:47:33 AM
Ok, the tool length offset table ;) I have no ATC :( :(

I'm going to try R8 ER collet chucks or the Torch TTS system as a repeatable method of tool holding, have asked many people and resounding reply was yes it should be plenty accurate enough for this style of machine, so....

1 - With the tool offsets, can I measure them using the Z axis probing and touch-plate setup?

2 - I guess i need a "default zero tool" or some-such to enable a reference length to be kept and then I would measure all tools against that one? This would be tool zero or 250 etc?

3 - If i was using the tapping head say, i would need to lower the knee about 5", ref the surface again, tap the threads then return the knee roughly to the higher position. Fit the next tool, set the tool number in Mach3, ref the surface and good to go again??

Am i on the right tracks here?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 20, 2016, 01:06:14 PM
Manual toolchange?

Anyone know the answer to this?

I have the CSMIO and the 2010 screen-set on my project.

In general settings i have "Stop spindle and wait for cycle start" checked in tool change options.

When i hit a Txx M06 command, the spindle stops, i change the tool, press cycle start but then it starts lowering the Z axis and i get a message "CSMIO probing z axis.."

I don't want to probe as i want to use tool offsets or probe only at the start of a program.

Something missing or not set right?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 21, 2016, 10:44:34 AM
Altered my safety and control wiring a little.

Fitted a safety relay - Telemecanique XPS-AS24v, this might look a little more complex but its not really. The benefit is that it has two separate output channels with contacts that are forcibly opened as well as constantly monitored internally, I have one output telling the CSMIO/Mach3 whether or not its in reset and the other channel supplying power via a contactor to my servo drives - also one N/C pair on this contactor is monitored by the unit in case it does not close or jams etc.

These relays seem much cheaper than the PILZ units shown in the CS-Labs book but have pretty similar functions.

I think that's about as safe as I can get it - if a drive runs amok, it hit a limit and kill power, same with Mach/CSMIO, the e-stop/limit chain is monitored for shorts etc, the only scenario where it gets shirty would be a runaway drive with the control contactor fused in the shut position but at this low power level thats pretty rare i think.

Of course, thinking of safety as we all do all of the time ;) I have just created an autonomous machine (runs from code) with open moving parts (cutters etc) that has absolutely no guarding or barriers anywhere :) Only mentioning this as it made me laugh when i thought of how many of the rules I have to obey all day in the print factory where i work have been broken, smashed, severely infringed or otherwise ignored :) :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 21, 2016, 01:45:39 PM
Did you find the issue with the probing on tool change? Just wondering if it has something to do with the screenset or possibly it could be something in your M6end.m1s?

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 21, 2016, 02:08:53 PM
Its the screens i think, Gerry says i need to either edit the macros or replace them with the bog-standard ones and try it.

The Z-axis is doing my head in ;)

My idea of welding it together is doomed to failure I think - the original bridgeport quill stop is porous and soaked in oil, any attempt to weld it simply creates a pool of oil and crap welds. I managed to tack it up but that only got me to my next headache....

Alignment is being a bitch - I cant seem to find a position where all the parts just play nicely, there is fair amount of stress and strain between the screw and the quill, it can be moved up and down but I'm not happy with it from an engineering point of view.

Not sure how to sort this at the moment, a right PITA.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 21, 2016, 02:18:14 PM
Strange about the alignment, the back plate cut out  should align with the milled out section on the head which should be perfectly aligned with the quill so should be fine.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 21, 2016, 02:25:46 PM
Yeah i think that part is ok, it could well be the weld pulling that is causing trouble, I am going to split the parts, clean up, and try one bolt through the middle - there is a large surface area so it should be sturdy enough, that will let me work it up and down with a dial indicator on it to see whats not true.

Its not far off, i'm just not happy yet ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 21, 2016, 02:57:07 PM
The connector I made just had a long bolt through it to the quill, think I actually made a brass bush that fitted the quill recess and machined a recess in the connector for the other end of the bush.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 21, 2016, 03:03:28 PM
Found a pic of the connector, sadly it is not the best for detail but it should give an idea of what I did. You can see the head of the bolt below the ball nut and the brass bush at the quill side.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 21, 2016, 03:11:39 PM
Nice, thanks again,

My idea is similar - the part that connects to the nut goes through the upright like yours, then i was hoping to simply join it to the original quill-stop block.

I think i may just have made things too tight - there is no slack where it connects to the nut, a smooth sliding fit, so any misalignment at all will cause binding and that's where i'm at.

I will open the nut hole out a little, get a dial indicator on it and see where its out.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 21, 2016, 04:57:53 PM
Ok, sorted it i think ;)

Couldn't rest without a fix so a couple of hours fiddling and a few thin shims later we have smooth motion from top to bottom, its pretty easy to reverse-drive it by moving the quill lever ;)

The bracket that holds the nut was slightly twisted and the nut hole was too tight, fixing both of those cured the problem.

Now i need to fix up some limit switches and get the motor hooked up.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 21, 2016, 06:13:51 PM
Good to hear :)
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on July 22, 2016, 05:24:52 AM
Glad you got it sorted.

Now I've seen the photo, it reminded me of the Matchmaker setup -
(https://c1.staticflickr.com/9/8367/8378588320_7f7ea1864f.jpg) (https://flic.kr/p/dLospj)Head (https://flic.kr/p/dLospj) by mc (https://www.flickr.com/photos/mc_mtb/), on Flickr
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 22, 2016, 05:53:09 AM
similar stuff, thanks.

the weak point is the connection between nut and quill, i can see a small amount of flex there when the quill is locked and i turn the screw pulley by hand.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 22, 2016, 02:20:20 PM
Started fitting switches tonight, picture below.

On the left we have
top = ++Limit for standard mill setup
middle = ++Limit for engraving setup
bottom = -- Limit

On the right is the homing switch for both setups.

The bracketry gets in the way of the fancy recesses for access to the tramming nuts but you can still get a spanner on them easily.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 23, 2016, 12:02:00 PM
Finally managed 3-axis motion :)

Picture of my final switch setup below, allows for my additional engraving spindle mounted on the big spindle - dual top limits and extended homing trigger.

A short video of simple code with two manual tool changes, Z parks at the top and the Y axis is shifted out of the way, whether this will work or no i don't know yet.

https://youtu.be/mJUxtS997MQ (https://youtu.be/mJUxtS997MQ)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 24, 2016, 07:11:44 AM
Scary stuff - she has cut her first steel :)

Spent the morning putting stuff back - trammed the head, fitted the vise and trammed that in, fitted a floating Z touch-plate and modified the touch-off macro so it did what i wanted.

Threw a small lump of 20mm scrap in, a duff 1/2" four-flute cutter and programmed a facing cut in Aspire of 0.5mm, seemed way slower than i would have moved if doing it manually - may not be a bad thing;) It gave me a speed of 140mm/min at 650rpm

Picture below - looks worse than it is, pretty good finish as it goes considering the state of the tool etc. and dry cutting plus unknown grade of steel.

Will try some drilling next.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 24, 2016, 09:16:56 AM
Nice, managed to spot-drill four points and the follow up with a 6mm drill thru (19mm)

Nice and smooth, no sign of anything odd happening :)

OK so we have issues to fix...

I am getting plenty of ePid faults - in the encoder plugin window I see red flashing 255 and encoder counts on all axes - I am really hoping this is caused by my idea of using screened printer cable (DB25) for the connections - its screened but NOT twisted pair and also there is a rats-nest of wiring on the bench now all 3 axes are bodged in.

So, what cable is recommended for the servo drive to CSMIO connections? Something like this....
http://www.ebay.co.uk/itm/BELDEN-9507-CABLE-9507-7PAIR-PER-M-/181883214948?hash=item2a59159c64:g:SRMAAOxyXzxTIj8s (http://www.ebay.co.uk/itm/BELDEN-9507-CABLE-9507-7PAIR-PER-M-/181883214948?hash=item2a59159c64:g:SRMAAOxyXzxTIj8s)

I tried messing with the tool length table but having it fault-out when probing is not safe so i gave up, could get my head round it anyway yet ;)

I think its time to start looking at control cabinets.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on July 24, 2016, 01:03:33 PM
I used CY cable to connect my drives to the Kanalog as that's what I had lying around, and have never had any issues, although the cable distance is only about 12-18".

CAT6e network patch cable, would give you shielded and twisted pairs cheaply, although it would be on the smaller side for wiring up, but as long as you're careful to make sure the wiring is well secured i.e. not relying on the terminals to hold it in place/support the weight, you shouldn't get any problems.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 24, 2016, 01:22:42 PM
Yeah, i did look at cat6 but really prefer stranded core not solid due to the risk of breakage. The stuff in the like is much cheaper elsewhere so i'll probably get some of that.

I'm just hoping that this is the issue, the encoder displays flash red either 255 or 179 i think it was - a list of these errors would be real handy, tried contacting CS-Labs but i think they are on summer shut-down.

I have read that it really is supposed to be twisted-pair for encoders so hopefully changing it to this will fix the issues.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on July 24, 2016, 01:32:44 PM
Cat patch cable is stranded wire. Patch cable is meant for making up the leads from sockets to computers, so is stranded for reliability and flexibility. Non-patch cable is usually solid core.

I think personally, I'd get everything installed and wired cleanly in a cabinet. Ideally twisted pairs are better, but standard cable should work just fine. The new encoder I just got for my lathe spindle came with standard un-shielded multicore cable, and it works just fine despite running over the spindle motor and past the VFD. I even tested it before fitting by running the spindle up to speed with the wiring in place, and it never gained any spurious encoder counts.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 24, 2016, 04:00:55 PM
Ah, yes i was thinking of cat network cable - not meant for moving, forgot about patch cable :)

I'll probably still get some better cable and solder the plugs up, it'll be better in the long run i think.

The MPG has plain cable too, shielded but not twisted, probably about 8' long if stretched out.

I'm sure the error numbers mean something - very annoying when they keep it secret.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 24, 2016, 05:46:36 PM
The way I like to connect my drives I/O up is have a short cable from the drive, shielded and preferably twisted pairs and have that going to breakout boards, you can then route from there to wherever they are going with the most suitable cable for the job. For encoders, analogue command etc I always use twisted pair, I have done some without shielding and it works fine but just short lengths and no where near anything noisy or mains voltage.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 25, 2016, 05:31:25 AM
Looks like a simple wiring fault - CS-Labs replied and the shielding is wrong.

My pre-made cable idea has the shield connected to the DB25 shell - this is then grounded via the drive socket. CS reckon that the shield must be isolated at the drive and connected to the ground terminal on the encoder input terminal (25)

I will make up some proper cables when the wire arrives this week ( i ordered some 7-pair stuff) , that should fix it.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 25, 2016, 08:15:20 AM
Had a reply from CS_Labs re the red flashing encoder numbers - they are not an error message, just a count of every error received from that encoder, it seems they only run from 1 to 255 though but any error is bad i guess so it spits out the "check encoder connection" message.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 25, 2016, 02:34:24 PM
Good to know what that means Dave :)
Shielding can be weird, on most things you only want one end connected but on the Hiperface encoders that are on some motors if you do not have both ends of the shield connected they will not work, I found that out the hard way :D


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 25, 2016, 02:41:52 PM
Their diagram, which i had not seen before as its not in the manual shows all encoder screens connected to pin 25 on the encoder port.

I just been poking about with my trusty Fluke and I have inadvertently connected to encoder shields to mains earth at the drives - probably not the best method ;)

Cable should be here tomorrow, bit of fiddly soldering and things should get better.

Still trying to find ideas for my semi-complex speed control method explained in my other thread ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 26, 2016, 02:19:44 PM
Ok, some success ;)

I replaced the cabling with 7-pair shielded cables and the encoder error counts are now below 50, not zero but they do not seem to change plus i do not get that 'Check encoder connections...." message anymore.

Looks like the counts are only zeroed upon boot up and i only booted it once but at least it seems happy now.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 26, 2016, 02:44:10 PM
Can't recall seeing any errors at all for the encoders on the Chiron,. maybe just didnt look. Is it on the debug page that you see them?

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 26, 2016, 02:49:43 PM
Nah, its on the Plugin Control -> CSMIO monitor screen
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 26, 2016, 05:15:47 PM
Ok so just on the General Info page of that rather than the debug page?
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 27, 2016, 03:16:46 AM
Yes the window that opens when you go Plugin Control -> CSMIO

On the left there are the encoder counts, if flashing red then an error was detected, the red number is the error count, it's limited to 255, at some level it triggers the "Check encoder connections..." message but i don't get that any more so maybe only when it hits 255 possibly.

I would guess an error could be a missing pulse or out of sync pulse?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 27, 2016, 07:29:27 AM
Had the Chiron running for 4hrs solid this morning  and had the window open and I have not seen any red numbers at all.

Just wondering if the output from your drives themselves are weak or noisy?
Have you scoped them directly at the drive to see what they look like?

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 27, 2016, 07:33:19 AM
No not yet, but as they appear to be stable now, i think it may be coming from the initial start-up.

I will play some more and check the numbers but if they don't increment any more, i will be happy i think.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 27, 2016, 01:17:04 PM
Odd - the error numbers tonight were exactly the same as yesterday - x73,y60,z56 and did not change at all while i was messing about so they are perfectly stable now and i am happy. Where the errors initially come from i don't know - maybe starting up the CSMIO with the drives turned off ??

Anyway the cable fixed it :)

Fault inputs - on the drives the outputs are opto-couplers with common ground so i guess sinking outputs.
I need to connect these to the input on the CSMIO, do i connect the input+ to 24v and the input- to the drive output?

I think thats correct.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 27, 2016, 05:52:51 PM
Sounds right for the Inputs,

Regarding the errors, it could well be because the drives are not on. My drives power stage can be off but the logic side is on whenever the IP-A is on and thus the IP-A always sees the encoders.
Do your drives not have a 24v supply for the logic side so that if supplied it will be on and only after you put mains to the drives the power side will be on?


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 28, 2016, 02:18:28 AM
They do have a 24v connection but i think its only used for the I/O connections possibly, it is on with the CSMIO so its not that anyway.

I'll keep an eye on it but i think its pretty good now, at least the numbers do not change once the system is running.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 28, 2016, 03:24:23 AM
Ok, control cabinets....

Using cardboard templates, I have worked out a reasonable layout and the size needs to be about 650mm wide, 850mm tall and 280mm deep.

Compared to the actual size of a Bridgeport this is a very big cabinet.

Should i mount it on the side, sticking out to the rear of the machine, go for floor-standing independent unit, wall mount it?

Whats a good idea here?

It will be steel, plasma cut and welded up i think - cheapest option.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 28, 2016, 07:31:04 AM
Does the display only light up when mains is applied? All drives I have had  have standby power, sometime mains, sometimes 24v and sometimes 5v.

Regarding the cabinet, I would not go for wall mounted. Free standing would not be my preferred option either but if room is limited then it may be the best compromise. However for me the cabinet attached to the mill is the best option as it means if the machine is ever moved the cabinet goes with it.

Usually the cabinets are either on the side or the back or sometimes both. On my CNC Bridgeport (that I no longer have) originally there were two cabinets, one at the side and one at the back. The modern drives etc allowed me to do away with the back cabinet. The Beaver mill had a massive cabinet on the back, over 1.5m high and 1.5m wide and 400mm to 500mm deep, I hauled that off and made an alu one  less than half the size and mounted to the side, in fact it was nearer 1/4 size.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 28, 2016, 07:36:54 AM
HI Hood,

Yes the displays only come on with the mains.

Will go for mounted option then.

PC is a bit of a PITA, I was going  to mount the guts inside the floating keyboard station but having had the lid off today to fit an SSD, I see the CPU has a heatsink thats about 6" x 4" with a 120mm fan mounted on front!

Thats going to make the pendant a bit big and clunky so I might just sling the PC complete into the bottom of the main cabinet and extend the Video/USB up to the pendant. Makes replacing the PC simpler too, and the pendant very slim now.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 28, 2016, 08:21:13 AM
Get yourself a mini ITX mobo with integrated CPU and passive cooling ;)
Something like this
http://www.kustompcs.co.uk/acatalog/info_55221.html

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 28, 2016, 09:37:23 AM
ah boy, more money ;)

its a good price though, have asked for a package price with ram, psu and mb to see if its worth it.


Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 28, 2016, 02:55:20 PM
What OS you running Hood?

I got a reply from that PC supplier and it won't run XP, Win7 is the oldest, but thats not easily available anymore or free either?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 28, 2016, 05:18:23 PM
I have xp on all my machines but on the desktop here and at the workshop I have Win7. You can get a genuine key on eBay, either with or without a disc. I think I paid about £15 for each of the Win7 Ultimates I have, one registered no probs automatically the other I had to use the automated phone service but again it was painless.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 29, 2016, 02:14:39 AM
Ok, thanks

Back to the encoder errors - yes it occurs when the drives are powered up.

I have a feeling it would not do it id the drives were powered before the CSMIO/Mach but then that would go against my safety system where you cant power the drives until mach is running.

I think i'll ignore it ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on July 29, 2016, 05:17:38 AM
Yes, not good to have the power stage of the drives enabled when Mach/IP-A is not.


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 31, 2016, 10:23:12 AM
Got the cabinet built today, an absolute monster and takes two to lift as i only had 3mm sheet in stock ;)

Its now sitting in the garden in satin black finish.

Also sorted out the mounting bars on the mill, just have to clean the crap out of the corner and pull the rack out to fit it :(
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 01, 2016, 05:33:15 AM
Front panel, physical buttons

Ok, just designing my floating pendant control station, so far i have this to go on...

stainless keyboard with trackball,
hand pendant with jog wheel, axis and multiplier switches
E-stop
reset for safety system
cycle-start
feed-hold
stop
coolant auto-off-manual
spindle motor toggle

am i missing some buttons??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on August 01, 2016, 06:48:46 PM
Spindle and feed override pots.

For Coolant I have two buttons, flood for normal and mist I use for the washdown hose.

Reference button is another I have.

I have a button for switching the computer on which in turn powers the 24v system etc.

Did have a few others but never used so I changed their functions, one was changed to Optional Stop, use that quite a bit on the lathe, not quite so much on the mill but still handy.

Have a drawbar release button but dont think you have a power  drawbar so....

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 02, 2016, 02:26:16 AM
Oh, course, forgot the pots, got them.

no flood on mill - makes way too much mess on an open machine.

PC is auto-boot when mains comes on.

I was going to fit ref button - z axis only, but can see use for separate X, Y, Z ref buttons now,

No power drawbar ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 06, 2016, 12:11:25 PM
Finally made some progress...

Got the cabinet mount on the mill, and the pendant station cut and welded, then mounted on a suspension arm, pictures below.

Started laying out the main panel now. :)

Not all the holes in the station will have buttons, thought it best to cut spares and fit blanks just in case.

Slightly concerned about the strain on the 10mm stud holding the arm on the rear of the ram but it seems ok.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 07, 2016, 09:58:59 AM
Started panel wiring today, one of my favourite parts of a build :)

Got the grounds and most of the neutrals in, plus the motor supply from the VFD to the terminal bar.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on August 08, 2016, 04:47:24 AM
Cabinet looks good, not so keen on the control panel but that is just personal taste, the actual build looks great.

I love the wiring process myself, one thing though, curious about the earth wires, why not use Din rail connectors?

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 08, 2016, 05:34:16 AM
Two reasons,,,

I have done it that way before,
Did not have any more terminals ;)

However, i have just found a source of terminals in a machine at work that is no longer used, i have a feeling it will be a bit lighter before today is out ;)

I agree, it would look a lot better and make use of that dead space.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on August 08, 2016, 05:51:21 AM
Old machines, best place for parts and you are recycling into the bargain :D

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 08, 2016, 02:46:35 PM
Ok, salvaged a bunch of din rail terminals, not proper grounding ones but will work nicely, looks a bit tidier too.;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 12, 2016, 10:02:44 AM
Ok, so its been a quiet day in the day-job today but couldn't sneak home to work on the project as it was my watch as they say :(

Been playing with Fusion360 :) Sort of come up with a plan for the top plate of my dual-spindle adaptor for the mill. My thoughts are in the machining process...

Steps...
Spot the three holes in the middle,
Drill them through,
Counter-bore them,
Rough pocket out the two big holes,
Finish pass on them,

Questions so far,

should i rough the holes then finish with a mill tool or should I go for the boring head and bore-gauges/caliper ??
I was thinking to then flip over in the vise, mill the slot on the rear face, then flip back, bolt to table on scrap pads through the big holes and do the outer contour followed by the two small slots and a chamfer pass?
How to chamfer the rear face once contoured?

So far its been a blast, love the 360deg view :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on August 12, 2016, 06:49:43 PM
Not sure of the setup of your aux spindle but would it not be possible to have an R8 on that plate so that it could fit into the spindle and save a bit of travel? You would need a rod on the plate going through a bush on the side of the head to stop it rotating but should be simple enough.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 13, 2016, 03:00:36 AM
Already there hood, here is a design i'm modifying / copying (pic below)

Its a H shape and my version will have a 20mm spigot that goes into an R8 collet in the spindle.

This part is only the top plate of the H, one plate would not be stable enough i think.

;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 13, 2016, 03:01:18 AM
Already there hood, here is a design i'm modifying / copying (pic below)

Its a H shape and my version will have a 20mm spigot that goes into an R8 collet in the spindle.

This part is only the top plate of the H, one plate would not be stable enough i think.

;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on August 13, 2016, 05:51:47 AM
Think it could be made stable just by having a guide rod or possibly two from the top plate and have guide bushing on the side of the head.
You could even use the guide rods to hold the two plates apart  instead of the  upright plate in your pic.
Now whether it would be worth it for the small gain in travel I don't know.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 13, 2016, 06:50:27 AM
Thats the thing, i'm only looking at losing about 20mm on Z so will still have 100mm + to play with - thats more than I have on the mini-mill so should be ok, the tools are all small apart from the Haimer - will have to move the table out the way to get that in i think. I can now see the advantages of a large Z travel, but sadly will never have it on this build.

Wiring the pendant up today, panel is finished, nearly testing time.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 13, 2016, 10:24:17 AM
Got the panel finished, bench-tested, all passed 100% :)

Got the pendant rough-wired so i could bench-test the panel, seems functional.

All axes homed and jogged perfectly, no surprises, e-stop system seems to work ok.

Managed to lug the panel into the cabinet, nearly ruptured myself but it's in now and bolted down.

Tomorrow will be final wiring on the switches and limits etc, plus re-rigging the pendant for the next power-up test. Then I'll probably strip the pendant and send it out for powder-coating, or just spray it if impatience takes over ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Mike VT on August 13, 2016, 12:54:45 PM
Looks very nice Dave.
What is the aux spindle for?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 13, 2016, 02:29:45 PM
Looks very nice Dave.
What is the aux spindle for?

Its a 24k rpm water-cooled spindle, great for aluminium and engraving etc, bridgeport only goes to 3000rpm.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Mike VT on August 13, 2016, 03:13:04 PM
Ahh.  Makes perfect since.

Have you done much engraving.  I would love to make my own face plates using anodize aluminum.  I currently purchase them.  They are all custom and I spend probably 10k a year on them.  Love the work they do but hate the lead time.  Always wondered how to in-fill the engraving.  Have you done this?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 13, 2016, 03:26:21 PM
no, not that much really.

Full story is that i built a mini-mill for cutting aluminium parts and to learn CNC, plus the fun of the build ;) Then realised that it took up a lot of workshop real-estate so decided to convert the Bridgeport mill as it was under-used, the idea being that the one machine could do both jobs - heavy stuff plus small light stuff. If that succeeded I would then sell the mini-mill to recover some cash.

Thats the theory anyway ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Mike VT on August 13, 2016, 03:45:06 PM
I get that.  Kinda how I got started and probably thought the same thing.  Years later, a big shop and always looking for a deal on another machine tool.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on August 13, 2016, 05:31:56 PM
Looking good Dave and glad it is all working as intended :)
Still not my choice of control panel layout but I will say it does look better now it is populated and will look even better once painted/coated :)

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 14, 2016, 03:39:08 AM
Thanks Hood, the good thing with the control panel is that I have plenty of spare cable-cores going back to the main cabinet and also its the easiest part to strip, rebuild or replace later on when i start to realise what is missing or in the wrong place :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 14, 2016, 10:41:03 AM
Got the panel wired back up, all tested ok :)

Got a few bits to sort out, need a longer cable for the canbus to the MPG module, tidy up the cables once i figure out how it all goes in use, fit the chip guards to the drive belts and z axis, strip and finish the control panel.

Nearly there but moved on a lot in a few days :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 16, 2016, 02:27:03 PM
Changed Mach down to V0.062 tonight, supposed to be best version, also got the Haimer 3d-taster zeroed, had to mark the spindle and mount as there is runout otherwise - this will need a bit of investigation, might be a burr in the R8 socket, might just be a poor 12mm Weldon mount that I have the Haimer mounted into.

Still testing the tool-length offset but it seems stable now I have sussed out how to do it;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on August 16, 2016, 05:11:52 PM
How are you liking the Haimer? I would find it hard to be without it.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 17, 2016, 02:21:20 AM
Well, not used it in anger yet as i'm still messing with the build, final steps etc. But it's a serious bit of kit, well made and looks like its exactly the right thing for the job, I have no doubts it will work fine once i get the first job on.

I think i posted many posts back about a little job i do batches of - round shafts with a square peg milled on the end and i asked about the CAM for it, I was using a 5C collet block and making four cuts, rotating 90deg each previously, someone mentioned standing the 5C block upright and working round it, but yesterday i realised what i really need is a pair of custom vise jaws with a half-round slot in each one - this would give me very accurate position and grip.

This will be one of the first jobs, plain mild steel will work as they will likely only be used for this job. Then I can just run round the tip with a 12mm ball-nosed cutter and speed would be greatly increased over the manual task.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on August 17, 2016, 06:45:48 PM
I use soft jaws all the time, the Gerrardi vice I have has holes in the top that you can bolt on soft jaws, quite expensive to buy them but I made 3 sets up.
I do prop shafts for boats on occasions and they have to stick out the hatch I cut in the Chirons enclosure, because the key is on the taper I need to tilt the shaft and because of that it won't fit out the hatch because of the vice height being too low, so I just welded a couple of blocks to the top of the soft jaws , problem solved :)

Another great thing about soft jaws is if you have to quickly grip a round bar for a quick job it is simple to just clamp something in the jaws which is maybe 10mm smaller than the dia  and 10mm shorter than the jaw height, fire up the circle wizard and cut a circle 5mm or so deep the same dia of the part. Remove the bit you clamped and then when you close the jaws on the part it is spot on and you already have the center, so no need for even using the Haimer :D


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 18, 2016, 02:19:19 AM
Sounds good, lots of learning to do i think.

The part i need is 1/2" round, 3" long and has a 5mm square peg machined on one end - a small chuck key style tool.

I tried doing CAM for the peg last night, seems Aspire will not let me do it how I thought in would, I am sure F360 will but that seems overkill.

I might have a stab at hand-coding the part for educational reasons, needs two passes, square corners, but cut with a 1/2" ball nosed tool so there is a radius between tip and body, DOC would be 11mm, steel is EN16T so a little harder than plain mild. Speed would be around 450rpm, 60mm/min on HSS tools.

Sounds simple, see how far i get ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on August 18, 2016, 02:31:40 AM
 it would be quite easy to do in fusion then it gives you the high speed cutting it is a lot faster cutting with fusion than vectric products but not as easy to use
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on August 18, 2016, 05:47:51 AM
The newfangled solutions addons are excellent for doing quick simple things like that.
Use them all the time, especially the circle and keyway ones. Can set to ramp in.
http://www.machsupport.com/shop/mach3-addons-for-mill/

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 18, 2016, 09:17:01 AM
After studying the ancient scrolls for a while, something like this might do it...

N1 T1 M06
N2 G90 G54 G00 x-20 Y-15
N3 S460 M03
N4 G43 H01 Z2 M08
N5 G01 Z-11 F500
N6 G41 X-3.75 P12.70 F60
N7 Y3.75
N8 X3.75
N9 Y-3.75
N10 X-3.75
N11 Y2.75
N12 X2.75
N13 Y-2.75
N14 X-2.75
N15 G40 X-20
N16 Y20
N17 G0 Z10 M09
N18 G53 G49 M05
M30
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 22, 2016, 01:58:05 PM
Found this on the welding bench this afternoon ;)

Should do nicely i think, also fitted the belt covers on the X & Y drives so she's chip-proof now :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 22, 2016, 02:11:38 PM
Signal conumdrum...

I have the VFD fault relay for the main spindle wired into the e-stop circuit, this is a N/C pair that open on fault, the second VFD is for the aux high-speed spindle but this one has a relay that energises to indicate a no-fault situation and drops out on a fault.

Sounds ok but the the relay being energised on no fault means it only comes on when the VFD is initialised and ready - catch22 as my e-stop will not allow it to come on unless the relay loop is closed :)

Is there a smart way round this - i don't want buttons that have to be held in while it initialises etc, could maybe use a short on-delay timer to short out the VFD relay until a few seconds after power-on but is there a better way????
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on August 22, 2016, 05:47:49 PM
Yes, PITA the things being that way, went through the same scenario when helping a friend with his lathe and a mentor spindle drive.
I think the timer relay is likely the best option.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 23, 2016, 03:26:23 AM
Yep, will head that way.

It's a bit like Homer Simpsons' Smoke alarm that goes off all the time to let you know there is no smoke ;)

Will dig a timer out of the junk box.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 28, 2016, 07:17:45 AM
Cut some button labels today, also had the console powder-coated :)

Still waiting on some knobs for FRO & SPO
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on August 28, 2016, 11:18:02 AM
Powder coating looks great :)

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on August 28, 2016, 01:29:15 PM
Yep, its a local place, does a damn fine job.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 01, 2016, 01:25:38 PM
Got the panel finished, just need to find or make some 22mm blanking plugs :)

I found tonight the limitations of a poor Z axis travel, did a test run on the parts that been discussed in my thread on work in different quadrants.

Ok so maybe i am being a bit overzealous by asking for a 35mm clearance plane, not sure, but when you take out the clearance plane, thickness of material, a little more for drill breakthrough, you are left with a  very small window of tool-height variation before the CSMIO throws a soft-limit-switch and bums out.

It needs the z axis to be zeroed when it's 36mm down from top limit - that allows the code to send it to Z35 for clearance, then you have to make sure that the shortest tool does not run it out of Z axis travel - i was going to use a slightly longer drill but will have to bum that idea and mill the holes or get stub-length drills etc.

It really is a lot more limiting than i imagined it would be, not having the ability to just throw the knee down a few turns to fit a big drill is an example - this would bugger the Z zero setting.

I guess i will have to run with much smaller clearance plane and double-check before each run that it misses the clamps etc.

Now i see why they make VMC's with 300+mm of Z axis travel :(
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 01, 2016, 05:41:51 PM
You will always run into a machine being too small, whether it is a lathe or a mill or a plasma or whatever.
Here is my Chiron doing the wedge holes on the lathe turret I made, 35 seconds in and you see how close the drill is at full height on Z, only 0.2mm clearance :D
https://www.youtube.com/watch?v=MUkyRjqGGow

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 02, 2016, 01:43:16 AM
I've said it before, but man, i love that basket tool-changer :)

Yep that was close on the drill. I think part my problem is still thinking manually, not CNC, you have to replace your brain with code and know what will happen before you press the green button.

In your case i would have dropped the knee and done two setups maybe but thats just a thought ;)

I can lower the clearance plane to miss clamps - even my generous 35mm would not miss the bolt/studs so maybe i was just going too far and using up z travel for no gain, 20mm will skip a clamp.

So much to learn.

I guess one test would be to park at clearance height and make sure the shortest tool for the job can reach the lowest point in the job and longest tool clears the work, if it passes that then it should run.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 02, 2016, 01:50:30 AM
In your case i would have dropped the knee and done two setups maybe but thats just a thought ;)

You would struggle to do that on the Chiron, table fixed solid and never moves :D
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 02, 2016, 02:20:53 AM
:)

The idea of using the knee to do tool offsets is pretty cool but moving the knee is not usually as accurate on a BP, i guess a direct feedback from a glass scale encoder would sort that but we're heading into exotic territory here ;)

I just have to increase my knowledge i think.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 02, 2016, 03:27:22 AM
Was always planning on doing the knee of the Beaver NC5 for use with tool offsets. Ray Livingston did that if I recall, should work well and as the Beaver already had a motor on the knee it wouldnt have been a huge job to swap.
 Not sure why you think the knee would be less accurate, as long as the gib was snuggled up then it would be just as good as the quill, in fact lots of people choose to do the knee rather than the quill, just it requires a much bigger motor and is often a lot slower.


Maybe  having a scale on the knee and cranking it manually and using a fixture offset for things such as drills would work, that way you could position manually with accuracy and then change the work offset to allow for the change in the height.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 02, 2016, 04:44:28 AM
Seems lots of ways to bake this cake, I need to get chips flying first i think :)

Any chance you could show us the code used on your tool height setter macros ?
Should have the ENC module today so i can get that fitted and programmed.

Dave
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 02, 2016, 07:22:42 AM
in the macropump I have

Setter = GetUserDRO(1502)
sleep 10
Setter2=Setter/200
SetOemDRO(100,Setter2)

In the screen button I have

If GetOemLED(800) Then
MsgBox ("Mach In Reset, Enable and start again")
End
End If

Offset = GetOemDRO(100)

SetOemDRO(1555,Question("Enter Offset Number"))

Tool = GetOemDRO(1555)

Code "G90" & "G10" & "L1" & "P" & Tool &"Z" & Offset
DoOemButton(121)     


And then I also have the zero button which just pulses the Index input on the Enc module.


I have OEM DRO 100 on my screenset but technically it is not required although it is handy as you see the numbers so you know it is working.


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 02, 2016, 07:33:01 AM
Nice, thanks again.

Is it possible to use the actual A axis DRO on screen - i already have that and the CSMIO will not be using it any more??

The index pulse needs a relay as it uses the index 5v supply ??

The /200 is your steps-per calculation?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 02, 2016, 07:39:10 AM
It may be possible but you would have to enable the axis for the DRO to read I would think and that may then cause issues with things like GoToZero or whatever.

I think you actually need to Gnd the I+ via the relay but not 100% sure but it sticks in my mind that we had to do that when doing my friends Avons height setter.


Yes my glass scale is 200 pulses per mm.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 02, 2016, 07:48:33 AM
Hmm, i might have to dump a small DRO somewhere then - thats the only thing with the 2010 screen-set, its so tidy and well filled that there is no where to shove anything else without making a mess :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 02, 2016, 07:59:23 AM
Not sure it won't work - i have the 4-axis 2010 set loaded on my laptop and with the axis disabled in ports & pins it seems to behave just like a plain user DRO - i can type values in it, made a macro that reads it, doubles the value then writes it back and that works so it could be good to go.

Goto zero has no effect as the axis is turned off :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 02, 2016, 08:06:09 AM
If it doesn't work then just make a tool set page on the screen, could even incorporate labels to read the tool names from the tool table like I have on the Chiron and also the Computurn lathe ;)

In Mach4 I have it one step better, I can write the labels on my page and it will update the table when I exit or I can update the table and it will get updated from it when I open.

Hood

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 02, 2016, 08:11:02 AM
Nice :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 02, 2016, 01:04:00 PM
Ok, i have the ENC module wired and i can see the LED's flashing as i move the encoder.

But i cannot get any signal into the CSMIO test page for the ENC module OR into Mach3.

Could it be the Index pulse ?
I have tried taking the Index input to 0v as well as 5v - no change, do i need to do anything with the differential Index input?

Nearly there but not quite ;)

Edit...

Got the data showing in the Plugin monitor, but not from the macro pump yet, going to change screen sets and throw in a user dro.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 02, 2016, 02:21:42 PM
Hmm, some progress.

I now have the macro pump updating the A axis DRO nicely, calibrated the display, got sensible data showing. The +Index pulse only needs to go low once after Mach comes out of reset each time.

Anyway, next issue seems to be that the macro code will not write to the tool table anymore?

Here's the button code, basically a hacked-down version of a previous attempt but one which did update the table ok.

It's not just writing a zero, i tested it by changing the DRO value with a fixed number and it would not write that either.

Code: [Select]
Sub Main()

Dim Response, Style, Tool

Style = 48
If GetOemLED(800) Then
  Response = MsgBox ("Mach In Reset, Enable And Start Again", Style, "Tool-Height Setting")
  End
End If

Style = 65
Response = MsgBox ("Ensure Toolsetter Is Empty, Reading Is Zero, Place Tool In Setter", Style, "Tool-Height Setting")
If Response = 2 Then End 'user pressed cancel

Tool = Question("Enter Tool Number For This Offset, Enter -1 To Abort")

If Tool = -1 Then End

Code "G90" & "G10" & "L1" & "P" & Tool &"Z" & GetOEMDRO(803)

DoOemButton(121)  'show the tooltable

Style = 64
Response = MsgBox ("Tool No." & Tool & " Height Set", Style, "Tool Height Setting")

End Sub              

Feet were aching a bit by now so i gave up without trying a PC reboot, will be back on the case in the morning but is there anything that can stop the code updating the table??

Also, when writing to the tool table in code then loading it via  DoOEMBUTTON(121) why doesn't the new value show up, if you close and reload it it shows?? This was when it was working BTW.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 02, 2016, 03:39:03 PM
My code works fine for me every time, opens the tool table and the value is there. Suggest you test initially by using the Encoder DRO (oemdro100) and see if you still have issues, if not then likely using the axis DRO is the problem.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 02, 2016, 03:42:50 PM
Thats what i suspected but i ruled that out by removing the DRO stuff from the macro and just telling it to write 5 as the offset - it would not even do this.

When i was messing with my automatic version before, it still did not show the new value in the table unless it was loaded, unloaded and loaded again?

Something odd going on here, will try again after a reboot in the morning.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 02, 2016, 03:45:15 PM
Take it you are using a version other than 066?
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 02, 2016, 03:53:32 PM
I think it was 062 i was previously advised to run.

Just been messing about on my laptop setup - that exhibited the same behaviour whereby the value was not shown in the table until reloaded.

I added a SLEEP 1000 between the Gcode being written and the DoOEMButton(121) and it works perfectly every time.

Will try this tomorrow on the machine but it seems it needs a small delay there?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 02, 2016, 05:19:52 PM
Not needed on mine but think scripts can run differently depending on the computer.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 02, 2016, 05:54:22 PM
Here is a screen capture video of what I was talking about in Mach4.
https://www.youtube.com/watch?v=pA8xeSCTlCA

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 03, 2016, 03:50:20 AM
Has Mach4 got CV yet or S-Curve acceleration, I hear thats pretty useful??

I would try it but just not as confident in it as i am with Mach3.

Yes this could well be a PC thing, these are Dell Optiplex Gxx boxes and i've read different things about compatibility but if the fix works then :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 03, 2016, 03:59:47 AM
Macros run in their own asynchronous thread.

Your "code" call simply buffers the line of gcode and the "main" Mach3 thread will execute it when its good and ready.

Meanwhile the macro has continued and executed the line to show the table. At this point, the gcode may or may not have finished (or for that matter even started) running.

This is why your sleep call is correcting things - but this is not the correct way to do it.

You need a while isMoving() after the code call to synchronise the threads.

That said - using the gcode interpreter to do this is a bit naff.

Lookup SetToolParam in the macro reference.

Here's the line though if you just want to wack it in place of the "code" call.

SetToolParam Tool, 2, GetOEMDRO(803)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 03, 2016, 04:08:43 AM
Ooh, that would explain it nicely, i did not know it worked through the buffer.

I will certainly try that code instead, thanks
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 03, 2016, 06:18:23 AM
Now we're getting there :)

The SetToolParam version works perfectly with no messing or pauses.

I will stick a bit of video up on the 'tube and a link later.

It's fast, easy, simple - just what is needed.

One oddity - after running the macro once and ok'ing the tool-table etc, the macro will not run again unless the Stop button is pressed?
I tried putting an "End" command on the last line but no change, i added a DoOEMButton(1003) and it works perfectly.
No idea whats going on there but hey-ho ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 03, 2016, 07:31:50 AM
Well, i am being driven to despair with this damn thing, honestly! If i could lift it, i would stuff it in the garden and torch it!

Thought i was getting somewhere, as usual, went to test the values stored which looked good on screen by doing a dummy setup and placing each tool then going to Z zero.

Normally when I put a tool in the "current tool' box the Z DRO updates to reflect the new offset. This has stopped working now, it either does nothing or updates to a random number or updates after a random length of time.

I video'd it here as i needed to cool off over a coffee...

https://youtu.be/FN248GRWwu0 (https://youtu.be/FN248GRWwu0)

It has values for tool zero - this should always be zero? A value of -881mm - thats a big offset!!
This has nothing to do with whats in the table.

Does this damn system actually work or what? I cannot see anything i have or am doing that can cause this???

Any suggestions?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 03, 2016, 08:17:24 AM
Have you tried with the encoder DRO or a User DRO rather than the axis DRO.
Try using my script exactly, it works for me on two machines and works for my friend on two machines and I have been using it for probably 6 years.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 03, 2016, 08:23:25 AM
Just to add, I am no VB programmer as is evident from my VB and Ian often laughs at the way I do things but the important thing is that  they work and never fail and that is all I care about. Maybe I am just the luckiest person out there and for some reason I never see issues with them?

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 03, 2016, 08:33:29 AM
Well, i'm not sure if it is the DRO or the macro pump BUT I have taken it all out of the pump, put the whole lot inside the setting macro - it now operates blind but works ok and all other functions have returned.

I will find my copy of MachScreen and throw a DRO in there and try again but its not installed on the box yet.

Very odd.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 03, 2016, 10:30:04 AM
Short video of it in use, this was with the A axis DRO which may have been the cause of some odd behaviour, not sure yet.

https://youtu.be/wqNGfHuCY4w (https://youtu.be/wqNGfHuCY4w)

Anyone know how to add a user DRO? I tried in MachScreen but it seems to only let me add OEMDRO's ???
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 03, 2016, 11:49:53 AM
Dave - do me a favor and turn your phone on its side - It's like trying to watch TV through a fence.

Post your pump macro and button macro and I'll take a look at the issues you posted in reply #430.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on September 03, 2016, 12:00:48 PM
Has Mach4 got CV yet or S-Curve acceleration, I hear thats pretty useful??

From the various discussions I can remember on the yahoo group, the trajectory planner is the main thing that has had minimal changes from Mach 3. However Brian has said due to the way Mach 4 has been designed/written, the TP is a module, so there is the opportunity for it be re-written later without any major alterations to Mach 4, unlike Mach 3 where the TP was a core part of the program.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 03, 2016, 12:06:40 PM
Thanks Stirling, zip file attached with the macro pump as it was at that stage and the macro that is called from a screen button.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 03, 2016, 02:01:09 PM
I don't have a csmio thingy so what does setting/clearing bit 5 of index 90 actually do?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 03, 2016, 02:06:09 PM
Its CS_Labs way of turning on and off the many outputs :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 04, 2016, 03:48:48 AM
NO - really? LOL - work with me here Dave. What does it ACTUALLY do? Does it turn a light on? ring a bell? make the tea? What is ACTUALLY achieved by flipping bit 5 on or off?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 04, 2016, 03:52:03 AM
Ahh, apologies, my misunderstanding.

That output merely flips a relay that controls which panel button LED's are lit - run, stop, hold, spindle etc :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 04, 2016, 04:27:52 AM
OK - not quite the exact answer I was looking for but anyway - so it doesn't actually do anything FUNCTIONAL - it's purely cosmetic. Is that correct?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 04, 2016, 04:30:24 AM
Definitely cosmetic, just a bell and whistle ;)

The code was taken from CS-Labs website.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 04, 2016, 05:01:54 AM
OK - moving on.

Taking out the chaf from your macropump code it resolves to the one single functional line of:

SetOemDRO 803, GetUserDRO(1502)/60.06041

I'm assuming that user DRO 1502 is updated somehow to contain the real time position (in encoder position) of the slider. Is that correct?

So FUNCTIONALLY, all the macropump code does is divide that by your scaling value and pop it into the A axis DRO.

Moving on to your button macro. Again, removing all the chaf, all it does is copy the A axis DRO into the tool table for a given tool.

So, if we (for the time being) fix it to tool 1. Your button code can be resolved to 1 line:

SetToolParam 1, 2, GetOEMDRO(803)

So use these two one liners for your macropump code and for your button code.

Then do your tool slider thing, press the button and then manually open the tool table and get back with the results.

Oh - one more question:

In post #411 Hood said:

And then I also have the zero button which just pulses the Index input on the Enc module.

What does "pulsing the Index input" actually do?
Why does Hood do it?
I don't see anywhere where you do it?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 04, 2016, 05:35:29 AM
ok, yes you are correct, DRO 1502 is a CS-LABS DRO, i guess its really the internal register where the encoder count is stored, you can view it on screen as a counter that goes up/down with movement of the encoder - having it as a DRO allows us mere mortals to do stuff with the numbers :)

The index pulse starts the counter in the CSMIO-ENC module, unless it is pulsed low after mach is running the counter does nothing, it is supposed to be the index pulse from the encoder so it resets every revolution.

I have tested this and it seems it only needs to go low ONCE every time Mach comes out of reset AND it can be held low all the time so is an edge trigger - this makes it really simple to implement automatically from Mach3 without buttons.

It does not seem to actually reset the count unless Mach goes into reset first then out then pulse the index low - this causes a counter reset, I don't know if Hood's version does or if this is normal?

Now, if the setter is not at zero when you reset it, you get negative readings which of course is bad, very bad as the tool length with be a mile off.

I just ensure the setter is at ref before getting going, in reality it never moves unless i move it.

I will try your code cut-downs and see what happens.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 04, 2016, 08:25:45 AM
OK - moving on.

Taking out the chaf from your macropump code it resolves to the one single functional line of:

SetOemDRO 803, GetUserDRO(1502)/60.06041

I'm assuming that user DRO 1502 is updated somehow to contain the real time position (in encoder position) of the slider. Is that correct?

So FUNCTIONALLY, all the macropump code does is divide that by your scaling value and pop it into the A axis DRO.

Moving on to your button macro. Again, removing all the chaf, all it does is copy the A axis DRO into the tool table for a given tool.

So, if we (for the time being) fix it to tool 1. Your button code can be resolved to 1 line:

SetToolParam 1, 2, GetOEMDRO(803)

So use these two one liners for your macropump code and for your button code.

Then do your tool slider thing, press the button and then manually open the tool table and get back with the results.

Oh - one more question:

In post #411 Hood said:

And then I also have the zero button which just pulses the Index input on the Enc module.

What does "pulsing the Index input" actually do?
Why does Hood do it?
I don't see anywhere where you do it?

OK, Done and it seems to work ok, I still have to press stop before the macro will run again though.

Now what :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 04, 2016, 08:38:07 AM
The setter is working ok, but something is upsetting macro operation, it will not do a manual or code M6 and it will not go to park position which is also macro controlled on the 2010 screen set.

???
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 04, 2016, 08:57:40 AM
Test with a default screen, maybe the 2010 screen does something which upsets things. Maybe it is even just the fact you are using an axis DRO but loading the default screen will let you know whether the screen is the issue or not.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 04, 2016, 09:10:28 AM
done - loaded 1024 set.

it thinks macros are running because if i MDI a macro call, nothing happens BUT if you then press STOP you get the message "Esc Or Stop Pressed, terminating macro script..."

The tool setter macro works ok but that has no axes motion - it seems that it affects only macros calling motion??

MDI'd G-Code works ok
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 04, 2016, 09:13:48 AM
Then maybe  try with oemdro 100, it is on the standard screen as it is the  4th Encoder DRO.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 04, 2016, 09:38:57 AM
OK, Done and it seems to work ok, I still have to press stop before the macro will run again though.

Now what :)

previously you said:

One oddity - after running the macro once and ok'ing the tool-table etc, the macro will not run again unless the Stop button is pressed?
I tried putting an "End" command on the last line but no change, i added a DoOEMButton(1003) and it works perfectly.
No idea whats going on there but hey-ho ;)

Hey-ho indeed - I strongly suggest you/we get to the bottom of WHY - rather than just appling a kludge and moving on.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 04, 2016, 09:53:10 AM
Ok, thats good advice, but I have no idea how to find out why it will not release until stop is pressed, there is no "Terminating Script..." message etc.

All i can figure out is that it works if Stop is pressed first??

Having said that, I need to test again since moving to a UserDRO instead of the Oem803 one i was using, it may just be the DRO causing the hang.

Will have to test this tomorrow night as there was an issue with the DRO chosen which is being fixed now, this will give me a DRO that is totally isolated from the general Mach system so should be safe.

I am doubtful though as I am pretty sure it was  the same when I had the code cut down so far there was no DRO at all - it just read the value and poked it straight into the tool table.

Will find out tomorrow hopefully.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 04, 2016, 10:05:48 AM
so we simplify even further.

Switch OFF the macropump - and make SURE it's OFF.

then run my one liner button code and see what happens. i.e. type a value into the A DRO and see if:

a) that goes into the tool table (again opened manually after the button press).
b)change the value manually in the A DRO and see if you can run the button again or whether it's "blocked" still.

Problem is of course - you've now got rid of the A DRO so we're in the mess of changing more than one thing at a time. See where I'm going with this? still thrashing Dave... ;)

EDIT: BTW - did I read somewhere that you're running macros from button macros or did I imagine that?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 04, 2016, 10:31:54 AM
I can easily change back to the std screen set so thats ok, will kill the pump and try the cut-down code again.

Yes, this screen-set uses macro calls on most buttons.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 04, 2016, 10:59:34 AM
Yes, this screen-set uses macro calls on most buttons.

How are the macros called? is it with the "code" call e.g.

code "M666"
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 04, 2016, 11:09:44 AM


How are the macros called? is it with the "code" call e.g.

code "M666"


That proves it, always knew you were the Deil  Ian



Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 04, 2016, 11:15:59 AM
 >:D
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 04, 2016, 11:42:51 AM
Yes, this screen-set uses macro calls on most buttons.

How are the macros called? is it with the "code" call e.g.

code "M666"


I can only presume as the buttons are not editable :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 04, 2016, 11:59:40 AM
no - what I'm getting at is prompted by this from Hood

One other thing, why did you have your screen button call a macro rather than just have the script in the button?
Unlikely it would make a difference but was just curious.

Hood

This implies you are calling a FILE based macro from within a screen button macro script
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 04, 2016, 12:08:33 PM
Ah, yes ok,

I have no idea how the internals of the 2010 screen set work, maybe Ger21 could chip in with some insight?

But if thats how you call a file based macro then thats probably how it works.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 04, 2016, 01:16:48 PM
Maybe Hood can help. Hood - where did you see Dave calling an M code from within a button script that prompted your comment I've quoted?

Meanwhile - what happened to this? i.e. what was the outcome?

I can easily change back to the std screen set so thats ok, will kill the pump and try the cut-down code again.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 04, 2016, 01:24:10 PM
Well the zip file of the code Dave attached had a macropump and M881.m1s.

So I presumed he was using the button to call the macro rather than having the script in the button itself.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 04, 2016, 01:39:33 PM
Ah - OK - it's just your quote is from Dave's "towel throwing" thread - I thought you'd spotted something over there that I'd missed. Thanks.

Sooooooooo..... Dave...

Are you doing a code "M881" call in a screen button?


Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 04, 2016, 01:46:47 PM
I guess so - the buttons part of the 2010 screen-set, it used to be the "semi-auto" manual tool-change setup but i cant use that on the Bridgeport as it needs a fixed touch-plate to get the reference height, works well on the engraver though.

I just pulled the original code from M881 that the button calls and replace it with my setter code - seemed like a good way to use an otherwise useless button.

It seems to do exactly the same as MDI'ing "M881"
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 04, 2016, 02:04:15 PM
Hood - should've said - good catch - I missed that.

Dave - OK - It's really not a good idea to call a macro from a macro using the "code" call - but putting that aside just for the moment...

you still haven't said what happened when you ran the one liner?

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 04, 2016, 04:05:04 PM

you still haven't said what happened when you ran the one liner?


I did, in post 446 - it did work but i still needed to press stop before it would run again.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 05, 2016, 04:53:13 AM
No - we moved on from that - see my reply #453

what were the results of doing that?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 05, 2016, 05:02:35 AM
Ah, got it, that was the point I ran out of time, it is on my list for tonight, will post answer when i get it tested.

To ensure pump is off, do you need to uncheck the option box and restart Mach or just uncheck the option?

Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 05, 2016, 05:45:49 AM
turn off and restart Mach3. However - when you come to turn it back on again - and restart Mach - make sure it's "taken" - here at least - sometimes you have to do it twice before the pump comes back on.

Anyway - no need - I simulated it all here and I'm getting pretty much the same results as you've described.

Turns out (here at least) that I can make it "work" by either using a USER DRO rather than the A DRO, OR by putting the M code in the button rather than using code "M..." from the button

If you use BOTH - like you're doing - it hangs the interpreter. So the M code never actually executes and (for example) the MDI is now hung.

So I guess the moral of the story is:
a) don't use OEM DROs for things they aren't intended for (which Hood was suggesting)
b) don't call M codes from macros (which I've been suggesting).

Just as an aside - during this I came across a bit of behavior which I don't really get. It seems that sometimes but not always (haven't investigated further) - if you have tool offsets cancelled, the mere fact of opening and then CLOSING the tool offset table turns tool offsets back on. That could bite you if you're not aware. E.g. you set a tool, you check the table, you set the next tool BUT you're now going to be setting the second tool with the first tool's offset applied to it - that's never going to end well.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 05, 2016, 06:07:53 AM
Your'e a star Stirling, and Hood, and I'm an ass ;)

I'm so glad it was not just me getting the odd results, even though it was my fault.

I have now got a custom screen set from Ger21 with the A axis DRO removed and replaced with UserDRO(1444) so that should solve all issues instantly as it will not be connected to anything internally.

I guess pressing the stop button resets the interpreter?

I will abort further testing and go straight for the new screen-set and test on that, no point in beating the dead horse any more.

Ger21 was right in his reply though as even Hood's suggestion of using the OEMDRO(100) i think, is a Mach DRO for encoder 4 although it seems it works ok for this usage as he reports. Maybe it is more allied to the Mcode calling issue than the actual DRO used as Hood has his code in the buttons??

As for your last paragraph I am still trying to get my head round that conundrum! Sounds like a real hornets nest of trouble there, is there a safe way to not run into that issue or prevent it happening?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 05, 2016, 06:37:40 AM
Just to nail the lid on this saga, I have modified the custom screen-set on which Ger21 kindly left a neat little gap next to my new user dro, and have managed to add a VB button, so i can now get rid of the double macro call as well as the OEMDRO issue - this should put my system perfectly in line with Hood's proven working version :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 05, 2016, 06:47:32 AM
EDIT: I posted this to reply to your previous post just as you posted your last reply. I can't be arsed to edit it so I'm pleased you've addressed BOTH issues.  ;)

I have now got a custom screen set from Ger21 with the A axis DRO removed and replaced with UserDRO(1444) so that should solve all issues instantly as it will not be connected to anything internally.

I'm hoping I've convinced you to address the M code as well.

I guess pressing the stop button resets the interpreter?

That would be my guess - though that was one thing I didn't see here. pressing cycle start STILL left the interpreter hung - but then I'm using an old version so maybe that was a "fix" for some related bug introduced sometime later.

I will abort further testing and go straight for the new screen-set and test on that, no point in beating the dead horse any more.

I'm REALLY hoping I've convinced you to address the M code as well.

Maybe it is more allied to the Mcode calling issue than the actual DRO used as Hood has his code in the buttons??

I'm REALLY REALLY hoping I've convinced you It's BOTH that need addressing.

As for your last paragraph I am still trying to get my head round that conundrum! Sounds like a real hornets nest of trouble there, is there a safe way to not run into that issue or prevent it happening?

I guess just being aware is half the battle. Don't have the time or the will to go off down another rabbit hole just now.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 05, 2016, 06:58:18 AM
Thanks Stirling, yes, i think I have now addressed all issues on this balls-up, i will try and refrain from "thrashing" again but to somewhat mitigate my balls-up, I did test the use of the OEMDRO manually before plunging in and it did seem safe, i was unaware of the M-Code issue as I presumed that as the 2010 screens was working very well, there were no issues in just editing one of the called macros' .

Anyway, I am confident that all the issues will disappear tonight .

Thanks for your patience, apologies for having a higher than average specific density in the brain area :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 05, 2016, 07:37:03 AM
LOL - no worries - hopefully you'll make some progress.

You'll probably know enough about my attitude to software by now to know why I can't let this one go without comment:

this should put my system perfectly in line with Hood's proven working version :)

Working - yes - proven - no. It works for Hood on Hood's system - but I've been around Mach3 long enough to know it WILL fail on SOME other systems.

One suspect area is this:

Code "G90" & "G10" & "L1" & "P" & Tool &"Z" & Offset
DoOemButton(121)

You hopefully know enough by now about what the "code" call actually does to know why this can fail.
Does it matter? Not to Hood and not to me - might do to someone who comes across this thread sometime and copies it though.  ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 05, 2016, 07:44:06 AM
Fair-do's :)

Yes i now know what can happen with those two lines of code, and also that the improved version fixes that issue, also not to apply a kludge over an issue even if it fixes it unless the issue cannot be fixed properly ;) Been very educational has this project.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 05, 2016, 03:49:54 PM
Ok, recent issues being fixed now, moving right along - servo tuning.

Have done nothing on these apart from an auto-tune in CSMIO setup. I thought the results were ok, but having spent a few hours today scouring the 'net it seems they were pretty bad really. The first video here shows one axis after an auto-tune. Now, I have zero experience with servo's being stepper builds up to this build, so I stand to be fully corrected but, i think the graph shows pretty bad over-shoot or oscillation?

https://youtu.be/IOAS4LMJzcg (https://youtu.be/IOAS4LMJzcg)

So, throwing caution to the wind, i dived in and removed all of the "I" and "D" parameters as well as the "ff" or fudge-factor i think its called. That seemed to improve things so i started increasing the gain in steps of 1,000 and the graph seems better to my untrained eye?

The following error is lower, dead-band is reached faster and the dials on the machine no longer overshoot and slowly wind back to a stop - this was a concern as i could see it affecting cut quality etc.

This video was shot after my messing around...

https://youtu.be/Yr4joMqo61Q (https://youtu.be/Yr4joMqo61Q)

Now, please feel free to rain on my parade, but does the last video look happier than the first?
Is there any issue running with zero "I". "D" & "ff" values?
I can't hear any grumbling from the motors, there is no visible 'hunting' at idle, following errors are down and the dials now stop on a dime as shown.

The Z axis would not tolerate as much gain and did go into permanent oscillation once so i backed off a fair bit but still no "I", "D" & "ff" values.

Suggestions?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 05, 2016, 06:23:43 PM
Not looked at the vids yet but if the following error is low, no overshoot, no hunting then doesn't matter a toss what values you have, every setup will be different.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 06, 2016, 02:14:39 AM
Thats pretty much what i was led to believe from my reading, seems permanent oscillation is bad even if it is tiny, slow settling is also bad from a contour point of view, and as you will see in the vids, it certainly looks better than the auto-tune version i think.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 06, 2016, 02:11:02 PM
Well that was a blast :)

I upped my speed and acceleration a bit, tested the motions again, checked the macro issue and all was good so went for the finish on  my part-done job. All went perfectly, tool-paths were good, CAM was good, CAD was good - this was my 1st part from Fusion360 too :)

Dimensions were spot-on as well, tool-changes were fast and easy as well. Short video of one of the cuts...

https://youtu.be/dzorJYUJpBk (https://youtu.be/dzorJYUJpBk)

Picture of finished part below.

BUT,

even though all went well the first check-run failed because mach started running the code without starting the spindle!
It would work from the panel button as well as the screen button but NOT from MDI or G-Code.

I have seen this before on the engraver and a Mach restart fixes it as it did this time, but of course you have to re-home. The only message you sometimes get is "Scripter compile error in M3.m1s" but as usual that file only contains DoSpin...

Any ideas??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 07, 2016, 05:08:03 AM
even though all went well the first check-run failed because mach started running the code without starting the spindle!
It would work from the panel button as well as the screen button but NOT from MDI or G-Code.

I have seen this before on the engraver and a Mach restart fixes it as it did this time, but of course you have to re-home. The only message you sometimes get is "Scripter compile error in M3.m1s" but as usual that file only contains DoSpin...

Any ideas??


How does your panel button activate your spindle?
How does your screen button activate your spindle?
Do you REALLY mean your M3 macro contains "DoSpin..."?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 07, 2016, 05:29:15 AM
Ok, the panel button has a hotkey associated to an input, the screen button has the "run macro" feature assigned to it, the M03 i couldn't remember the exact contents then so i was trying to infer that it had the bog-standard contents, i have just looked and it contains exactly "DoSpinCW()" nothing more.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: stirling on September 07, 2016, 05:46:13 AM
OK - the screen button - (back to a familiar issue) what is the actual code in the button?

Why am I asking?

Well if (for example) the button code is doSpinCW then it's NOT calling the M3 macro and that tells us something. However if it's got (for example) call "M3" in it then it IS calling the M3 macro and that tells us something else.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 07, 2016, 06:34:47 AM
All i can do is go into screen4 designer and look at the button - this is on the 2010 set, it just has Oem Code Function 110 in the box, there is no vb code etc.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 07, 2016, 02:21:33 PM
Ok, so i did a home-all tonight and noticed the X axis was wobbling when doing the back-off part of the home sequence so it seems my inept attempt at servo tuning was lacking somewhat. In the graph i could make it do the wobble-thingy at about 13% speed and it looked bad.

Reading the CSMIO manual, the tuning section is a bit vague but it seemed i needed to reach oscillation first then back off. Having seen what that does, i thought it safer to tune for the lowest following error and fastest dead-band arrival as i had read on various other papers, there does not seem to be any "scientific" method to tuning, just get it smooth, fast and oscillation free.

Tweaking the values in PID order, i have now got far better following errors and as yet no wobble;)
Values are now...
X P=20,000 I=50, D=0, ff=65 Following error 135 at max speed
Y P=20,000 I=50, D=0, ff=65 Following error 105 at max speed
Z P=12,000 I=65, D=0, ff=60 Following error 253 at max speed

These errors are much lower than before and it seems happy at all speeds now so will leave it there for now.

The spindle started ok as well tonight - this seems to be a random problem.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 09, 2016, 03:50:32 AM
USB Issues?

I need USB in the control pendant, USB keyboard/trackball and USB socket for code loading.
Currently i have a cheap 4-way hub and extension but windows is not happy and i get multiple "new device found" chimes every time i start up or plug in a USB stick

Is it best to try a powered hub or run separate extensions to the PC??

The length needs to be 5m to reach.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 09, 2016, 03:32:19 PM
Never had the m1s problem but my friend did. If you open the M3.m1s macro in notepad you may see some artefacts there other than the DoSpin(), delete if there are and then save. Also may be worth deleting the m3.m1s and then make a new one manually.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 09, 2016, 03:59:15 PM
Ok, thanks Hood, will have a look in the file.

I have fixed the USB issue too - get rid of the hub and just run two extensions back to the PC, works fine now.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 09, 2016, 04:01:55 PM
I am not a fan of USB, it is very temperamental at times but sadly it needs used on occasions. I do prefer PS2 for keyboards/trackballs though I do have USB ones that mostly run ok. On the Computurn lathe I have a powered hub and even that will occasionally stop working, usually just the touch screen though.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 09, 2016, 04:07:23 PM
Yeah, read about the PS/2 but none of my pc's have the sockets anymore, just USB now.

It seems to put up ok on the plasma ;)

I think i added some clip-on ferrites there though, will get some more.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 09, 2016, 04:10:33 PM
PS2 seemed to disappear for a while but it seems to be back, certainly is on every recently bought mobo I have had.

One thing maybe to look at is the power options for your USB in Device manager, make sure windows can not sleep if it thinks it is inactive.

Hodo
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 09, 2016, 04:15:18 PM
In fact I just bought that mobo I pointed iout to you a wee while back, nice wee mobo which will be going in the lathe if I swap over to Mach4. Put win7 Pro on it, COA for £8 on eBay :)
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 10, 2016, 09:56:38 AM
At last - the adaptor I have mucking about with for the last couple of months is finally done  ::) Admittedly it took so long as i was building the machine to make it and figuring out how to operate it but in the end, after ironing out all (so far) of the bugs in tooling, offsets, post-processing etc it really only took a couple of hours.

Its also the first part designed in Fusion 360, that was a learning curve!

It fits the mill snugly and as long as the high-speed spindle motor fits ok, should work beautifully, still got some jobs to clear before i can strip that down though.

Total cost in Z axis travel is 22mm - not bad i thought - that leaves me about 95mm to play with but on a small spindle with tiny tooling that should be ok i think.

Thanks for all help guys  ;) ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 11, 2016, 08:45:45 AM
I'm almost ready to move my smaller parts to my Bridgeport conversion from the mini-mill. The spindle mount adaptor is made and the wiring/programming should be good to go. The bed needs to be about 350mm x 450mm

Picture below of my mini-mill with a just-finished part still mounted, I need to make a sub-table to replicate the bed of the mini-mill on the Bridgeport.

So, what would i be looking at here? The existing bed is 15mm ecocast but is sitting on a 15mm slab of cast iron which is bigger than the sub-table. The Bridgeport has a relatively narrow table at 230mm so the sub-table will overhang, max rear overhang is 20mm so more to the front. The lump of MDF in the second picture is about the right size, sitting on the mill.

Now, I have about 5 parts i make occasionally, none in quantities big enough to deserve a custom fixture plate so the universal sub-table seems the best way forwards?

What sort of thickness here?
Would it need support arms underneath for the overhang?
How to mount easily onto the Bridgeport?
Better idea?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 11, 2016, 01:46:27 PM
I originally made a plate to fit to the Chirons table, think it was 40mm thick and I used sections of it to make two full length supports so that it was raised up further as it needed to be 80mm above the surface so small tools would reach.
I now have a very nice Gerrardi vice which opens to 300mm so I rearranged the supports on the bottom of the plate and just clamp the whole thing in the vice when I use it.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 11, 2016, 02:20:52 PM
Nice :)

Tool reach not an issue here, just need to figure how thick to go, maybe 25mm?

Needs to be removed easy so don't want to go massively overboard especially as the biggest tool that will be run on it would probably b 6-7mm :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 12, 2016, 10:19:49 AM
Ooh tapping-head time....

Will have some 6mm holes to tap soon, can play with my tapping head, not quite meant for CNC as its an auto-reverse model meant for pillar drills etc but hey-ho :)

It needs to feed in 5mm less that hole depth, then stop - the device will then feed that last 5mm and disengage the drive, you then feed out and the device reverses the tap out, it works very nicely in a manual BP ;)

On to CNC, the best way, after a lot of pi$$ing about seems to be to use a boring cycle with dwell and feed-out in Fusion360.

For testing purposes I chose an M6 tap with 1mm pitch, 500rpm and 500mm/min feed, 10mm deep blind hole.

I have been doing simulations etc and this is the code i get for two tapped holes...

Code: [Select]
(1)
(T10  D=6.1 CR=0. TAPER=118DEG - ZMIN=-5. - DRILL)
G90 G94 G91.1 G40 G49 G17
G21
G28 G91 Z0.
G90

(DRILL2)
M5
M9
T10 M6
S500 M3
G54
M7
G0 X0. Y0.
G43 Z28. H10
Z8.
G98 G89 X0. Y0. Z-5. R3. P4. F500.
X20.
G80
Z28.

M9
G28 G91 Z0.
G90
M30

I think it reads ok, it has the delay (exaggerated for testing) and will feed in and out.

Am i on the right track here?

I couldn't find any G89.. codes in Aspire, seems too advanced for it and has no boring, threading etc so Fusion360 is the best way i have, apart from hand-coding and i'm not at that stage yet.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on September 12, 2016, 03:18:17 PM
Dave post on the fusion forum the EE will say how to do it
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 12, 2016, 03:33:34 PM
Already on there, amazing - they have since edited the post processor so it can use a tapping cycle but feed out and not rapid out - they are just doing a bit of fine tuning on it now :)

Great forum there.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on September 12, 2016, 03:35:44 PM
the keep it very professional
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 12, 2016, 04:27:48 PM
Got it working now :)

Modified post - I can now use a tapping op with feed-in at feed-rate then a dwell and feed-out at retract-rate, just what the doctor ordered :)

I just have to make some notes on using it as i need to make sure the retract height is at least 5mm above the surface as when the tapping head is in reverse the tap protrudes 5mm more than when it went in :) The dwell will need setting on the job as it will be speed dependant but the tapping head has a limit of about 800rpm anyway.

Should do the job nicely i think :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 19, 2016, 02:20:38 PM
New spindle arrived today, did it fit my 3d designed and cnc machined quill clamp?

Damn right it did, fitted like a glove  ;D ;D

Setup the VFD - totally different than the mini-mill, the CSMIO seems to be far better and with spindle pulleys at std setup - 0-24,000 rpm it matched speed 100%, no messing no fuss.

Just got to finish machining the sub-table now, could have got it done at the weekend if i didn't bend the probe on my Haimer  ::) and no, I didn't remember to order a spare tip  >:(

Got two on the way to me now though, lesson learnt.

In the above post, i mentioned being able to set the feed rate and retract when tapping with the TapMatic head - This was wrong, the post calculates all the settings based upon the tap pitch chosen in the tool library - much easier, I just need to get the actual speed as close to selected speed as possible.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 21, 2016, 06:24:26 PM
Get an encoder, rigid tapping is sweet :)
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 22, 2016, 02:25:23 AM
Yeah but no but...

Would it be as sweet with an old motor and vari-speed mechanical drive on top ??

Doubt it.

I will revisit the servo replacement at some stage, just a matter of cash and finding the right motor that will do the speed and the torque/power needed.

I already have the ENC module fitted so thats one step further ;)

Just need a motor that can do 3000rpm with the same sort of torque/power as the old motor has AND be able to run on my limited power supply of course - I cant just bung on a 5kW servo and gear it up for the speed as it would pop the supply breaker :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 23, 2016, 05:35:32 AM
Think I may have found a working motor replacement setup...

Motor...
https://inverterdrive.com/OrderCode/22060/ (https://inverterdrive.com/OrderCode/22060/)

Drive...
https://inverterdrive.com/OrderCode/27487/ (https://inverterdrive.com/OrderCode/27487/)
Plus the braking resistor.

Would be in sensorless-vector mode, will still need an encoder on the system somewhere.

At 1:1 it seems to have most of the torque needs met, maybe push a little belt reduction and go to 125Hz to boost the low end a bit further while keeping the top end.

Hard part is mounting the encoder - will have to go on motor shaft as the draw-bar means i can't use the spindle shaft - guess that will mean i am limited to 1:1 ratio??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 23, 2016, 02:54:36 PM
Tested the tapping head tonight in some scrap, should work very nicely, only needs a short 0.8s dwell at the mid-point to allow the clutch to disengage. Have to do the spot-drill and drilling as one setup then follow with tapping as the knee has to drop a lot to fit the tapping head in  ;)

Also discovered that run-from-here seems to make a mess out of tool-length offsets, no damage as it was only dry run and also the first time i tried RFH, In the end it was safer to do the part of code i wanted as a separate file, i think i'll keep that in mind.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on September 23, 2016, 03:02:04 PM
Hard part is mounting the encoder - will have to go on motor shaft as the draw-bar means i can't use the spindle shaft - guess that will mean i am limited to 1:1 ratio??

Got any photos of what space is available?
There is nearly always some way to mount an encoder.
Reflective optical encoder just needs a stripped wheel. Large bore encoder discs are available, which you could possibly mount on the toothed spindle pulley. Third pulley running on the belt between the main pulleys, or on the motor shaft, but both those options would need to allow for a gearing ratio. If you do need a spindle index pulse (Would it actually be used?) you could then use a slot sensor via a notch on the spindle pulley flange.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 23, 2016, 03:14:47 PM
Still researching this, i was looking at mounting a differential output encoder somewhere in the head, maybe a small pulley mounted on the spindle running a lightweight toothed belt - plenty of room in there when the mechanical speed stuff is pulled out.

I am pretty certain it needs an index pulse.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on September 23, 2016, 03:29:37 PM
I'm sure Hood will give a more definitive answer, but I can't see any real reason why an index pulse would be essential on a mill that doesn't need any sort of spindle indexing.

If you've not looked at it already, US digital (www.usdigital.com) is probably the best place to see lots of encoder options.
Maybe also worth checking British Encoder (www.encoder.co.uk), although they're mostly complete units i.e. you can't get sensors and discs separate like you can at USdigital.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 23, 2016, 03:38:18 PM
Thanks, thats a good point, will be fully researching this before diving in :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 25, 2016, 07:27:49 AM
Job done :)

100 holes spotted, drilled, countersunk, blind-tapped M6 :)

Picture below is the finished sub-table and here's a short clip of my peck-drilling...
https://youtu.be/7pixPYu1UFA (https://youtu.be/7pixPYu1UFA)

The surface parallelism measures 0 to +0.03mm in X and 0 to +0.02mm in Y so I'm not even going to bother doing a facing cut.

The tapping cycle was almost perfect, the modified post processor had a +10% retract rate - this was wrong as you could hear the tap pulling on the last thread as it came out, I've modified the post so that it's 1:1 all the way now.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 26, 2016, 10:21:18 AM
Back to a possible motor upgrade....

SO, we fit a decent motor, 3Hp seems to fit the figures, a new sensorless vector VFD and throw an encoder on top which is connected to the CSMIO via the ENC module.

Am I right in believing the spindle speed would then show up in Mach3 as the correct reading from the the encoder?

Would the speed be a closed-loop in that if I ask for 500rpm, it will give me 500 not 490 or 510?

Just figuring whether or not to keep this idea on the burner or shelve it for a while ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 27, 2016, 04:45:57 AM
As far as I know the CSMIO requires the Index pulse and it is definitely required for peck tapping.

As far as the speed control, there are two methods, open and closed loop, how well either will work will depend on how good the VFD can control the spindle I would think.
I have never used a VFD with the CSMIO, don't like them all that much. I have however used the CSMIO/IP-S and the 0-10v output with a servo spindle and it was spot on, reason I did that was it was before the CSMIO/IP-S had the option to use Step/Dir for a spindle.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 27, 2016, 04:54:20 AM
Thanks

the cost between a new 3Hp motor/vfd/encoder and a servo is about the same

BUT

I cannot get the servo to match both speed AND power it seems - this means running a far bigger slower servo and gearing up.

The 3Hp AC motor has plenty of torque down to silly speeds according to the specs - something like 15Nm at 146rpm all the way up to 8Nm at 2900rpm

The servo seems only affordable at 1.8kW /6Nm & 18Nm peak 3000rpm. Any bigger and cost goes silly.

It does seem the CSMIO is geared towards servos.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 27, 2016, 05:11:55 AM
Is it possible for some kind soul ;) to say one way or the other if a 1.8kW AC servo is just too weedy to replace the 1.5Hp7Nm AC motor i have already??

My views are restricted by knowledge and muddied by confusion :)

The original motor has about 7Nm - with the mechanical vari-speed probably about 15Nm at bottom speed 450Rpm but only about 2.5Nm at top speed 3000rpm

The servo has 6Nm continuous and 18Nm peak - now I have no idea what "peak" is or how long it can maintain it before going Chernobyl on me ;)

This is where my knowledge runs out.

Simple question, forget cost, will the servo work or will it stall out at low speed ?

Bearing in mind this is a Bridgeport and not a metal hogging monster so heavy cuts are intermittent.

Knowing this would simplify my choices by narrowing things down a bit .

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 27, 2016, 06:43:39 AM
Remember our previous chats on the subject Dave?
Torque may well be fairly constant, HP/KW will not be, whether that is with Servo or Induction motor via VFD.
You are trying to compare a variable geared motor which is ALWAYS running at full HP/KW and a servo or VFD controlled motor which is only running at the rated power when at rated speed, torques may well be close but will the servo/VFD have the power to do the work in the required time? That is the reason when servos or VFDs are used  they are always bigger than you would get away with when using a variable geared motor.
Gearing is the best of both worlds in this instance, where it falls down seamless, accurate  variable speed adjustment on the fly.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 27, 2016, 06:58:31 AM
Yes, i do recall, but still confused :)

And to muddy the waters a bit more, I do have the motor on a VFD at present, to get my speed range semi-adjustable from MAch3  I am running the mechanical controller only in one of two positions - 700rpm and 2200rpm, the rest of the variation in speeds from 450 to 3000 is covered by the VFD running from 25Hz to 75Hz.

It sort of works reasonably well, Mach gets its knickers in a twist at times but mostly all good so far.

Now, I have no idea as to what this is doing to the power from the AC motor but I guess its not all good, thats why i limited the range from 25 to 75Hz only, its an old motor and not made for inverters so did not sound too sweet at 100Hz and was useless below 25Hz

Also throw in the serious power losses from the vari speed drive - i did read a paper somewhere that listed 75% efficient so thats a pretty big loss.

Any of that help me - i doubt it ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 27, 2016, 07:25:22 AM
Trying to get the lightbulb to come on....

If i have a tool that takes 20Nm to rotate it and a motor that can provide 20Nm torque but zero Hp - would that mean the tool just stands still?

Then if i want to propel that tool forwards into something (my head probably) at say 100mm/min I need to increase Hp above zero to some positive figure that i have no doubt can be calculated?

So my theoretical tool might need 20Nm and 5Hp to make it move at 100mm/min ???

Probably still in cloud cuckoo land.... ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 27, 2016, 08:06:03 AM
That is basically it Dave, HP is the power required to move a mass a given distance in a given time. If you look up the charts on manufacturers sites you should find info on the HP required to drive a tool at the optimum feed, this info is readily available for drills and taps certainly, milling cutters not so much but in most cases they would be less anyway unless really chewing metal.

Regarding your servo in the example above, at 450rpm it would only be about 0.3KW.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 27, 2016, 08:18:28 AM
Nice,

Been messing with my speed/feed calculator, looking at all the figures i usually ignore ;)

Mild steel,
50mm facemill with 5 tips, full-width cut, 1.6mm deep = 420rpm, 201mm/min, 0.4kW 9.24Nm
20mm endmill 4 flute, 35mm DOC, 5.4mm engagement = 650rpm, 204mm.min, 0.81kW 12.12Nm
15mm drill = 650rpm, 111mm/min, 0.37kW 5.5Nm

So using your quote of 0.3kw at 450rpm the answer is NO it will probably stall on a 15mm drill and a 20mm endmill but be ok with the facemill.

Yes, I *could* enter the actual power curve into the calculator and it WILL give me a solution BUT I think going lower power than a 1.5hp Bridgeport is a little pointless.

That clears that up then I think, forget the servo, if anything IS to be done it will be a 3Hp AC motor, sensorless-vector drive, braking resistor and encoder I think.

Thanks all for the patience ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 27, 2016, 08:46:37 AM
There are servo drives out there that can run off single phase and are rated 3Kw, for example an Allen Bradley DSD-030 (note NOT the DSD-HV030) which I use on the big lathe. On the Z Axis I have a H4075 motor which is 9.9Nm cont and 3000rpm. so about 3.14Kw. On the  X axis I have a H4050 motor which is  about 6.6Nm cont and 4000 rpm so approx 2.8Kw.
Problem is they are scarce second hand this side of the pond and are extortionate at the other side. You can also get the older drives, DDM-030 but again rare on eBay over here.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 27, 2016, 08:53:14 AM
Thanks Hood, I think the servo idea has been passed now, will focus on what is achievable with a vfd/3hp induction/encoder setup i think.

Was a nice thought but just not worth more cost than the little servo i was looking at.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 27, 2016, 09:31:08 AM
Small encouragement from CS_Labs....

With their ENC module, a vfd and encoder, activate the Pid loop in Mach3 using their settings, it will give reasonably closed-loop operation as far as speed regulation goes as well as real-time display of actual rpm on the screen :)

Sounds good to me, I have the ENC module already so thats one step less.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 28, 2016, 10:15:56 AM
Parts on order, went for the Ac motor with vfd and braking resistor with encoder fitted somewhere ;)

Be good to get rid of the clattering vari-speed stuff up top at last.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on September 28, 2016, 02:47:31 PM
The Encoder ideally needs to be 1:1 with the spindle so if you have no gearing then on the motor would be fine, if gearing then you would really need to mount a pulley/belt setup for the encoder directly from the spindle.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on September 28, 2016, 02:56:05 PM
Drive is 1:1, 8mm pitch HTD belt 30mm wide

I was thinking of making a new bottom cover - the one that sits under the motor - and joining up to the motor shaft with something.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 01, 2016, 09:54:14 AM
Todays lesson...
When CAM'ing a part, don't program the spot-drill to go from stock top to -2mm from stock bottom when you really wanted -2mm from stock top ;) ;) ouch!

Todays question...

I had the Scripter compile error in M3.m1s again, so the machine starts up and as it had a drill bit mounted and i was already over the hole location it happily pile-drived the stationary bit into the work:(

There seems no trigger for this error, its random, there is no error in M3, it was half way through a 6 tool job, it's always bad news and the only fix is to restart Mach3, re-home and carry on. Sometimes you can hit the E-stop in time but if its close to the part location then it usually just piles in.

Is there a setting or a way to get Mach3 to abort motion if there is a script error or indeed ANY error? It seems stupid putting the message on screen and just continuing???
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 01, 2016, 11:41:53 AM
Re the script compile errors, there are a good few posts on the 'net about it, no solid answers though :(

Various versions of Mach affected, the only common response is to delete the macros folder and let Mach create a new one then copy back your custom macros, tools and offsets.

Not great and no answer as to what causes it.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 02, 2016, 07:24:34 AM
Another not so great day, infact i nearly gave up. :'( 30 minute job takes over 3 hours.

Simple job - two setups, total of 5 tool changes, motor mount/adaptor plate for my new drive motor, basically a 250mm circle with 110mm hole in the middle, plus some bolt holes, tabs etc. A nice fun part to play with?

First tool/pass goes well, then the Z gets the command to home for tool change - this triggers a (soft) limit switch, right on the tool change. Reset pressed, tool changed, Z ref is now wrong, reset, pass runs ok, tool-change time - (soft) limit triggers again, same routine.

Offsets look odd but maybe correct, i haven't figured out the numbers yet - pictures below.

The screen tells me max-z is something like 220mm? A bit tricky as i only have something like 130mm to play with? Surely my Z-Max has to be Zero?

Then i start a run and as soon as it hits the first X/Y G1 line it throws an ePid fault, and again, reset, swear, go indoors and re-cam the part for a single tool in the file and it runs OK ?

Its just winding me up something terrible as I am not 'fiddling' with stuff or editing macros etc, I just went out, booted up and tried to do some work.

I have no idea what to fix or what to post up here so other can chime in but boy is it pissing me off.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 03, 2016, 06:16:12 AM
Anyone?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 03, 2016, 07:38:26 AM
What do you mean by,
"this triggers a (soft) limit switch"
Is it a real switch that you have set up in some way so as to be an addition to the hard limit switches or are you meaning you get a message saying that you have exceeded the soft limits?

Is your tool change position right on the soft limits? If so then could be servo overshoot just taking it past them slightly.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 03, 2016, 08:45:35 AM
No, this is an internal limit of some sort, not a physical switch at all and not mach soft-limits as i dont think you get a message on screen when they trip.

It seems to be a CS_LABS thing - if the g-code tells it to go somewhere it knows it cant I get a message on screen - "Limit switch triggered"

This has only ever happened on the CSMIO machine, never on the plasma or mini-mill.

It's like something is getting confused, especially if not only ever when tool-length offsets are in play.

Seems to be the G28 G91 Z0. line that sometimes triggers it but only after the first tool has been run???
It uses that line at the end of each tool to send the Z right up to machine home.
Maybe i need to get the post edited to use G0 G53 Z0 instead?

Its a bit complicated to note exactly what and when it happens.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 03, 2016, 09:14:36 AM
Ok well could it possibly actually be a limit switch has been seen? Could be vibration or noise and the switch is seen for a very short period by the IP-A and thus the message as I think that is the only time you would get such a message.
Might be worthwhile setting a small amount of fitering in the IP-A plugin and see if it helps. You will find it on the Misc IO page, it is defaulted at 1 (4ms), might be ok if you set it to 2 or so if it is just occasional.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 03, 2016, 09:35:37 AM
Ok, will try that but there is no message when jogging into a soft-limit zone?

It can't be a physical limit as they are all wired to the safety circuit first so any false triggering there will throw the safety relay out first killing the power, the only other switches are physical homing ones, they are all industrial stuff, roller levers, with very large travels so a false trigger would not happen there as well as the fact that they are all mounted well away from the actual physical travel limits and i use a home-offset.

It was random as such that it does not always do it but then repeatable as in it was always after the first tool-change and always when it sent the Z to home.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 03, 2016, 11:31:52 AM
Not sure what you  mean by
"Ok, will try that but there is no message when jogging into a soft-limit zone?"

If you have softlimits set up with the IP-A and jog to them the axis will stop dead at the soft limit and you will only be able to jog the opposite way, no message though and no slow zone like other controllers have as the IP-A knows exactly where the axis is and can stop it at the defined accel in motor tuning and it is spot on.

What you said above was the message mentioned Limits, not Soft Limits, and that is the reason I think it is a Limit signal that is being seen.

How have you got the limits set up? You say they are wired to the safety relay but do you have an input from the safety relay going to the IP-A that is set up as a Limit ?

Only time I have ever seen the IP-A give a limit message is when I hit a limit, ie when softlimits are disabled and it actually hits a limit  and the only time I ever have the soft limits disabled is when I initially set up new machine. I do that so  that I can find the positions of the limits in Machine coords for setting up the soft limits.

So I still think it is likely to be an issue with the limit input to the IP-A and for some reason it is seeing a signal momentarily.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 03, 2016, 01:52:45 PM
The limits are wired to the input side of the Telemechanique safety relay, the two output channels are connected to the supply contactors and an input on the CSMIO.

The input to the CSMIO is set up as the e-stop input.

Yes the message is in the message line on screen and says "Limit switch triggered" - it will do this even before moving an axis if it thinks it needs to move somewhere it knows it cannot, at least thats the way it seems.

This is code related in that it never does it when i'm just jogging manually or with the jog-wheel, and only ever seems to do it after the first tool change.

Maybe it is related to the screen-set, this is the 2010 one.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 03, 2016, 04:55:43 PM
Might be the screenset but can't really see how it could be, worth a try I suppose. As said only time I have ever seen a limit switch message the same as above is when I have actually hit a limit switch.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 03, 2016, 05:03:42 PM
Yep its an odd one.

As soon as i have the new motor fitted, i intend to repeat air-cut the same code as before and see what happens.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 05, 2016, 04:41:12 AM
Something that rarely gets mentioned but was brought up by my motor change...Power required...

I now have a 3ph 2.2kW spindle motor on a 230v vfd, 700w X AC servo, 700w Y AC servo, 400w Z AC servo, maybe 100w for pc and controller on this machine.

How do i calculate the supply capacity allowing for diversity - it will not be running 100% flat out all the time, far from it :)

I know i need to uprate the MCB's and supply cables as the build was originally for the small 1.5hp spindle motor and I only fitted a 10A mob for the spindle.

Adding up the maximum ratings for all drives gives a figure way more than i can supply because of no diversity allowance :)

Any thoughts?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: RICH on October 05, 2016, 05:41:29 AM
I would suggest you size  to comply with  the National Electric Code and local code.
Amp draw can be measured if you have a snap around ammeter.

Ask a licensed electrician or electrical designer as they can tell you quickly all that you need to know
and save you the time of trying to interpret / read the code.   

RICH
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 05, 2016, 06:06:23 AM

Amp draw can be measured if you have a snap around ammeter.

RICH

Ah, no but i know where i can borrow one ;)


Thanks, will ask the sparks that maintain the business in my day job.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Stuart on October 05, 2016, 07:29:38 AM
Dave

A quick and dirty calc you would need at least a 25a mcb high inrush one

Run 4 mm T&E

 Make sure you fit a mains filter to the VFD they are dirty what nots your servo drives will thank you

As I have been out of the sparks trade for 20 years I may have over sized things

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 05, 2016, 07:32:29 AM
Thanks, will have a look for a filter, do have one but is only 14A so will have to come out.


Yes UK
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 05, 2016, 08:23:25 AM
Just had a chat with the supplier and he recommends not fitting an input filter as the Bosch inverter I have already has a good internal filter filter to the input, that is unless there is proof of interference on other components.

Also, peak demand for my motor/drive setup in a balls-to-wall full-load situation would be 22.5A on the supply, above that level the inverter will start reducing speed, prolonged heavy draw will trigger a shutdown - the point at which this happens can be adjusted with the settings.

Now, question is, can a Bridgeport actually USE 3Hp at the spindle without snapping something :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Stuart on October 05, 2016, 08:42:23 AM
Ok. Dave

If the supplier says no filter that's a done deal , but is that a dealer or Bosh themselves


All my experience ( yes I still do a bit and keep up with things) filters are necessary particularly if there are more electronics on the same feed , if you fit one put it next to the VFD

But then I am old school better to be safe than sorry , we all no that CNC machines do some funny things at times

Now back to the play pen ( workshop) to make some small bits on my small CNC mill that I have refitted from the Far East nearly motion controller under mach3 to ESS an mach4 no wiring dia and all wire the same colour with nine limits to sort out is was fun

Take care and be safe

Stuart
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 05, 2016, 08:53:42 AM
Its a supplier i have used in the day-job for some years and is very helpful/knowledgable so i will go with the advice for now.

Gotta love the far-east wiring colours :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 05, 2016, 02:22:47 PM
Got it running under local control tonight, did an autotune on it, draws a tad over 3A idling.

Question -

When speeding up or slowing down (by twiddling the knob) it overshoots and then stabilises - I *think* this is the sensorless-vector stuff doing its thing.

Now, as it will be running in semi closed-loop when finished, is it best to leave it in SVC mode or switch to standard V/Hz mode ?



Looks like i have usable power from 300 to 3000rpm, 10 to 100Hz
Stopping from 3000rpm in 1s pretty impressive too :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 06, 2016, 07:32:26 AM
Going back to my issue with the odd behaviour and imaginary limit switches triggering, I have just got a reply back from CS-LABS and unknown to me, the controller plugin creates a log file - "CSMIO_IP_A.log" somewhere on the PC, they said it should contain details of what switch was triggered and other stuff.

Will have a look tonight, nearly finished the new drive motor so should be back testing by the weekend hopefully.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 06, 2016, 01:53:04 PM
Here we go, the log file is a mine of information :)

It seems the machine started up fine, ran fine until 2016-10-02 | 09:52:21.375 where we get the first "Software limit switch activated!" error - this would be when it sent the Z axis home for a tool-change.

So, as i said, its not a real limit switch thats getting hit, its some sort of software limit.

Its also the Z axis throwing the following ePid fault - 2016-10-02 | 09:56:24.625 -> ePID Fault on Axis(2) : FAULT

Question is - why?

2016-10-02 | 09:17:24.718 -> CSMIO-IP class initialized OK.
2016-10-02 | 09:17:24.734 -> InitUDPSock -> OK.
2016-10-02 | 09:17:24.734 -> piInitControl: Module filename: C:\Mach3\PlugIns\CSMIO_IP_A_plugin.dll
2016-10-02 | 09:17:24.734 -> piInitControl: GetFileVersionInfoSize = 1716
2016-10-02 | 09:17:24.734 -> piInitControl: ProductName: CSMIO-IP-A Mach3 plugin
2016-10-02 | 09:17:24.734 -> piInitControl: ProductVersion: 2.8.5.1
2016-10-02 | 09:17:25.687 -> Our IP address : 10.1.1.1
2016-10-02 | 09:17:25.687 -> Our subnet mask : 255.255.255.0
2016-10-02 | 09:17:25.687 -> Calculated broadcast : 10.1.1.255
2016-10-02 | 09:17:25.687 -> Sending discover message to broadcast.
2016-10-02 | 09:17:26.359 -> All network interfaces checked...
2016-10-02 | 09:17:26.359 -> Discover finished. Found 1 CSMIO-IP device(s).
2016-10-02 | 09:17:26.359 -> Connecting to CSMIO-IP at IP:10.1.1.2
2016-10-02 | 09:17:26.359 -> Connected.
2016-10-02 | 09:17:27.109 -> llComm(c:45): Rx time-out. retry = 0
2016-10-02 | 09:17:27.109 -> llComm(c:45): NAck with nackTRREP received. (no retry).
2016-10-02 | 09:18:05.171 -> Sending reset to idle state request.
2016-10-02 | 09:18:07.218 -> Homing start axis:2
2016-10-02 | 09:18:12.296 -> ClrAxisPos: Axis:2 / DeRef: NO.
2016-10-02 | 09:18:12.296 -> Axis 2 homing ok.
2016-10-02 | 09:18:12.359 -> Homing start axis:1
2016-10-02 | 09:18:15.546 -> ClrAxisPos: Axis:1 / DeRef: NO.
2016-10-02 | 09:18:15.546 -> Axis 1 homing ok.
2016-10-02 | 09:18:15.640 -> Homing start axis:0
2016-10-02 | 09:18:22.515 -> ClrAxisPos: Axis:0 / DeRef: NO.
2016-10-02 | 09:18:22.515 -> Axis 0 homing ok.
2016-10-02 | 09:52:21.375 -> Software limit switch activated!
2016-10-02 | 09:52:58.843 -> Sending reset to idle state request.
2016-10-02 | 09:55:34.437 -> Software limit switch activated!
2016-10-02 | 09:55:42.453 -> Sending reset to idle state request.
2016-10-02 | 09:56:24.625 -> ***********************************
2016-10-02 | 09:56:24.625 -> ePID FAULT! (State = 105)(Alarms=0x00000002)
2016-10-02 | 09:56:24.625 -> (ThreadSt=5) (RTappSt=0)
2016-10-02 | 09:56:24.625 -> ePID MaxError on Axis(0) : 156
2016-10-02 | 09:56:24.625 -> ePID MaxError on Axis(1) : 1
2016-10-02 | 09:56:24.625 -> ePID MaxError on Axis(2) : 681
2016-10-02 | 09:56:24.625 -> ePID MaxError on Axis(3) : 0
2016-10-02 | 09:56:24.625 -> ePID MaxError on Axis(4) : 0
2016-10-02 | 09:56:24.625 -> ePID MaxError on Axis(5) : 0
2016-10-02 | 09:56:24.625 -> ePID Fault on Axis(0) : ok
2016-10-02 | 09:56:24.625 -> ePID Fault on Axis(1) : ok
2016-10-02 | 09:56:24.625 -> ePID Fault on Axis(2) : FAULT
2016-10-02 | 09:56:24.625 -> ePID Fault on Axis(3) : ok
2016-10-02 | 09:56:24.625 -> ePID Fault on Axis(4) : ok
2016-10-02 | 09:56:24.625 -> ePID Fault on Axis(5) : ok
2016-10-02 | 09:56:24.625 -> ***********************************
2016-10-02 | 09:56:34.296 -> Sending reset to idle state request.
2016-10-02 | 09:58:19.750 -> Sending STOP request.
2016-10-02 | 09:58:19.812 -> ***********************************
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 06, 2016, 02:12:49 PM
CS-Labs also stressed that it can be connected with a DRO?

"Even the fact you do not use UserDRO 1001 can be the problem - please verify it."

As far as i can see, the 2010 screen-set does NOT have the DRO1001 on it - "Gage Block Height"

Any ideas?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 06, 2016, 05:06:49 PM
What do you think they are meaning about Gauge Block DRO? Are they saying it should be set to zero and they think there may be some value in it?
If you load the standard screenset you will see what value is in the DRO, you can then set to zero if that is what is required and then go back to your normal screenset.
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 07, 2016, 02:10:03 AM
It's zero, checked on the 1024 set.

I have no idea what they are leaning towards, I also asked Gerry who did the 2010 set and he has no idea either, the set does not use the 1001dro though.

Baffling

No macro's were in play at the time - it was before the M6 so M6Start was not called and M6End is empty anyway, no probing was being done so the gage block height is irrelevant.

I have passed the log data back to cs-labs
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 07, 2016, 06:11:08 AM
Ok, reply from CS-Labs, my comments quoted in the reply start with >>>....

Dear Dave,
 
>>> As you can see, the system started up normal, then had a software limit switch activated - this was caused buy this line of code - G28 G91 Z0.
 
Soft limit limits are set out and passed to CSMIO/IP-A by  Mach3.
If Soft Limit was set correctly the obviously Mach3 made a mistake during Soft limit calculations or during passing to the controller.
 
>>> Then once i reset Mach it followed with an ePid fault on this line I think - G0 X109.987 Y168.641 or this one - G43 Z25. H2 which followed.
 
The e-PID mens too high difference between  currently set by Mach3 trajectory and currently set axis position read out from encoders.
The fault may be caused by Mach3 and servo drives as well.
 
- E-PID caused by Mach3.
The fault is mostly caused when Mach3 makes a mistake during calculations and it wants to perform very fast uncontrolled axes move.
A corrupted  XML file is usually responsible for that. The e-PID fault may be also caused by incorrectly written VB macros.
 
e-PID caused by servo drives.
That's nothing else but max. following position error exceeding of one of axes.
In this case you should verify your PID loop settings (tuning).
 
I would only like to add that for a milling machines we always use 03.043.022 Mach3 version as it's the most reliable in our opinion.
Version higher than 03.043.045 of Mach3 can sometimes cause problems with synchronization of internal coordinates so it's easier to get the e-PID fault.
 

Now, in my mind this looks like an internal Mach/CSMIO thing because in theory you should NEVER be able to exceed or trip a soft-limit - thats the WHOLE reason they exist, to control the boundaries of motion right?

So, somehow, my code for home is trying to send Mach Z axis beyond Mach Z++ soft-limit home setting - this is clearly wrong no?

Any thoughts?


So, it seems i need to downgrade further, anyone have a link for V022 please?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 07, 2016, 09:17:53 AM
Just been advised by a respected guy that v022 will not work as it has issues with tool-change routines that are not out-of-the-box seems v028 is better.

I'm holding off on downgrading until i have retested the same code that failed.

Slowly losing faith.........
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 07, 2016, 01:09:43 PM
I use 062 and have never had an issue but I suppose each system can be different. You will find all available versions on the ftp site.
ftp://machsupport.com/ (ftp://machsupport.com/)

022 is going back quite a bit and I wouldn't be surprised if some things don't work, as an example I was messing around trying to find the problem with the CSMIO and Lathe threading and went back to an older version and threading was suddenly much improved (slow pullout being the problem) The Spindle Speed Override however didn't work in the older version.

Anyway, it seems like the G28 line is the problem, I never use G28 I use G53 instead, wonder if that could be the difference? I also do not go to Z0, I think mostly I do a G53G0Z-2.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 07, 2016, 01:19:17 PM
Yeah, i could get the post modified - this is Fusion360 and the posts are gibberish to me ;) but the forum is great.

In my Aspire posts I use G53 G0 Z0.

Z0 or Z-2 will work, 2mm is not worth worrying about, but its odd that it only fails AFTER a tool change - something must get messed up internally i guess.

I cammed the job with one tool per file and it worked fine, at least it got the part made :)

Will be playing this weekend, just have the encoder to fit now, Mach is controlling the new VFD/motor nicely now.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 07, 2016, 01:54:47 PM
When I had the CSMIO controlling a servo spindle on the wee lathe, in the days before the IP-A allowed Step/Dir spindle, it was very good. Very linear and very accurate in revs. I thought this may just have been because it was a servo but a friend has a lathe with a DC spindle motor and a Mentor Spindle drive and he is using 0-10v and he says RPM are spot on as well.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 07, 2016, 02:02:16 PM
Yep, my mini-mill took hours of farting about with spindle pulley values to get reasonably good linear control - the CSMIO just nails it straight out of the box, its about +10-15rpm out at any speed but thats no bad thing really.

I might increase braking time a tad - 1s stop from 3000rpm is pretty hard and tends to slam my worn dogs out on the back-gear clutch.

Apart from that its all gone well so far, just need to rig up a bracket for the spindle encoder, wire up and see what happens then :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 07, 2016, 02:25:41 PM
I've grasped enough to edit the post processor and change the G28 lines to G53 G0 Z0 :)

I'll still air-cut the original file - it would be nice if it fails again, then try the new version and see if that passes or fails :)

It would at least point the finger at the G28 stuff.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 08, 2016, 03:46:37 AM
Will be good to see what you discover.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 08, 2016, 05:37:06 AM
got the encoder fitted, anyone know what settings i need to activate in the system to close the loop?

I tried activating the pid loop in mach and it makes the speed oscillate wildly so i turned that off again for the moment.

in the picture attached, i have now activated "Spindle DAC" as without it there was no speed control at all but is that enough, do i need more stuff set here?

Any tips????
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on October 08, 2016, 05:56:42 AM
You generally need a lot of damping to run closed loop with a VFD, as they are usually very slow to respond in comparison to a servo drive. Try dropping P to near zero, and I&D to zero as a starting point. Personally, as you're running direct drive, I'd be inclined to leave it running open loop, as the VFD itself will maintain near constant speed.

Regarding your G28 issue, have you got an example of the code?
If the post processor is inserting a co-ordinate as part of the G28, it could well be causing a move outwith machine limits. Have a read of this article - http://www.cnccookbook.com/CCCNCGCodeG28ReturntoReference.htm
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 08, 2016, 06:04:28 AM
Thanks, i'll have a play with the pid values.
If running open-loop, do i need the encoder at all, can't remember now what function it performs ??

The code was just G28 G91 Z0.

I'll read the link later.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 08, 2016, 07:22:50 AM
After hitting the problem with both G28 and G53 moves I switched to single block and stepped it, it triggered at the M6 command.

Next i pulled the M6macros out and it worked ok, a coffee and a sit-down with the macro open showed the problem. It was connected with the screen-set and the M6Start macro, a variable and DRO called "Clearance Plane" - this is used in the 2010 screen-set tool-change routines.

But as I cannot use them on the Bridgeport and do not need them due to the fixed length tooling, the already edited M6Start macro was still using the values and trying to send the Z to a position beyond home when triggered.

This is why the code always ran fine as a single-tool job - the first line in the M6Start skips the routine if the current tool = selected tool so the dodgy code was never hit :)

I have now edited the M6Start to remove all references to clearance planes, offsets etc and just issue a straight G53 G0 Z0 style home move.

The code i was struggling with has now been air-cut 6 times with 100% success.

Thanks for all the tips.


Now, back to "what is my encoder actually doing???"   :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 08, 2016, 08:08:33 AM
Good you got it sussed :)

Encoder gives spindle speed reading in Mill and also more importantly allows rigid tapping :)

If I recall for true spindle speed reading with the IP-A/S you need to make sure the Averaging is disabled in Ports and Pins.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 09, 2016, 10:00:21 AM

Encoder gives spindle speed reading in Mill and also more importantly allows rigid tapping :)

If I recall for true spindle speed reading with the IP-A/S you need to make sure the Averaging is disabled in Ports and Pins.

Hood

Ok, I have spindle-speed averaging off, closed loop spindle control off, use spindle feedback in sync modes on.

There is no change in speed displayed, BUT does it need a certain DRO to view real speed?

The 2010 screen-set uses DRO 202 - "Overridden spindle speed" only - this just seems to show requested speed, i would expect an actual-speed display to show some variance when running??

Maybe it needs DRO 39 - true spindle speed instead - i can easily swap them over i guess if thats the one?

Did some more cutting today, just modifying my vise jaws for a job coming up, deliberately took some fairly heavy cuts on a 20mm tool down at 500rpm and the new drive setup didn't even notice :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 09, 2016, 11:17:07 AM
Yes, OEM 39 is correct.

Good news about the VFD :)
Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 09, 2016, 11:26:42 AM
Great, will tweak the screen-set and try again.

Yes the vfd/motor setup seems well matched and didn't even notice the cut :)

I think the project is just about done now - checked the high-speed spindle setup again yesterday and that is all set now, needed a wiring change due to changing the vfd for the main spindle - the safety relays are different.

How do i verify if the encoder setup really is ready for rigid tapping?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 09, 2016, 01:23:36 PM
Just download the plugin and place it in your macro folder (Version 2 is best option I think).
http://www.cs-lab.eu/en/artykul-110-NEW__threading_macros__two_versions_decription.html

Zero the Z axis at a safe point and then MDI the following
G0Z5

M84 Q-20 P1.5 S200 R400

The M84 line will  go to z-20 with rpm of 200 at 1.5mm/rev and then will retract at 400rpm at 1.5mm per rev.

Not sure if your spindle needs to be turning initially or not as I don't think I have ever used it without the spindle on prior to calling a M84


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 09, 2016, 02:21:17 PM
Thanks Hood, will test that.
 :)

Is there any indicator to look for to show things are or are not set right?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 09, 2016, 02:30:46 PM
I would imagine it would error if not correct.
Only thing with a VFD is you may travel slightly further than the commanded depth.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 10, 2016, 02:19:37 PM
Well thats good news...

Seems to work just fine with the M84 macro :)

Tried various pitch and depths all the way up to 5mm pitch which is a bit steep :)

Couple of notes though - it needs a good headroom on Z above the start point as it overruns on the withdraw and will trip the soft limit again. Also at 300rpm it will overrun the reverse point by about 3mm on a 1.5mm pitch, just need to be aware of that :)

A little video...
https://youtu.be/ttz_LNAEEdA (https://youtu.be/ttz_LNAEEdA)

It certainly tracks the rpm as i was gently applying the spindle brake while it was doing its thing and you can clearly see the Z drive belt changing speed with spindle speed :)

Also, the new DRO39 now shows real rpm - nice.

I played with the Mach pid loop again and although it did stabilise the speed at exactly the requested speed, it took a while to do so, i'll leave that off i think.

So, what sort of tap holder do i need to look for - floating, fully rigid??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 10, 2016, 02:48:05 PM
ER collet holder does fine for rigid tapping, no need for a floating.

No overrun with a servo spindle or even if you could utilise +/-10v with a VFD and tune via the plugins PID. With the open loop VFD then you will get the overrun.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 10, 2016, 03:10:35 PM
Pretty certain the vfd only supports 0-10v plus fwd/rev signals and not +/-10v so cant use the CSMIO servo DAC output or pid.

Not to worry, i think it will do fine, just need to assess the overrun before diving into a job and make allowance.

:)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 10, 2016, 04:59:11 PM
Just call it short, run it and see how deep it goes then alter the depth and run again if it wasn't deep enough.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 15, 2016, 07:19:39 AM
Was recently asked for some videos, here we go...

Rigid tapping...
https://youtu.be/1UOak0qTHsY

Full machine conversion walk-around...
https://youtu.be/utjrP_94KIk

:)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 15, 2016, 02:34:04 PM
Looks to be working well :)
I can see all spare pieces of metal in your workshop will soon have tapped holes in them :D


Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 15, 2016, 02:45:08 PM
LOL

Already found a use for a bunch of aluminium offcuts - the support bracket to hold the auxiliary spindle when not in use. Will be mounted up where the lifting eye goes on the top of the ram.

Designing it now in fusion - loads of tapped holes, chamfers, multiple tool changes, facing, boring, counter-boring the works :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 16, 2016, 08:04:25 AM
Here we go, nice fun little project for a Sunday morning....

Fits perfectly, works well and used loads of tool changes :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on October 16, 2016, 09:26:56 AM
Nice :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 23, 2016, 10:04:48 AM
Future thoughts...

Machine is working very nicely so far. However I still have big doubts about the weakest link in the system - the Z-axis drive, its a pretty tortured setup, the connection to the quill is poor being just one bolt, the block face is only around 15-20mm square where it bolts on, there is around 75mm from the quill to the ball-screw so there is a massive twisting moment acting on the joint and the ball-nut.

There is already movement visible between the nut and the quill - you can see the connecting arm twisting when nudging the ball-screw pulley by hand so it would be pretty rough under drilling or plunge-milling forces. I can see a very short life for the ball-nut as they don't like twisting moments, axial or radial but not twisting.

It was assembled with loctite but with only the one bolt I doubt that would do much.

I have a feeling it would have been better to go with the drive idea in the pictures below, the quill rack is designed to take all the Bridgeport can do, there is not much backlash and what there is could be helped with a gas-spring maybe to keep it under positive pressure.

No idea what the pinion gearing ratio is but likely something like 3" per turn so would use a bigger reduction from motor.

Just looking ahead, but as i said, I can see issues here already and thats only after a few jobs....
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 24, 2016, 04:28:58 AM
Thinking out loud...

With the drive to the quill rack, probably from the left side as done in the FlashCut kits etc, without measuring i  think the quill pinion does 2 full turns for full travel so about 75mm/turn, with a 4:1 or maybe 5:1 belt reduction from servo to pinion shaft, would that give enough resolution/torque - the motor would only ever do 8 or 10 full revs??

Just working things through...
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 26, 2016, 02:53:18 PM
Quill drive reduction idea, mk1, pictured.

Gives a 16:1 reduction, takes up little space, relatively easy to build.

Mounts to left side of head onto the 6 screw holes no longer used.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 27, 2016, 08:52:24 AM
Anyone have a video or link to some pics of a powered knee mill conversion?

Seems a lot of people rate it but i cant find any proof!  :)

Still deciding which way to go.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: RICH on October 27, 2016, 10:55:30 AM
Dave,
Here is a link to what I did on my Atlas mill for what it's worth.
http://www.machsupport.com/forum/index.php/topic,7396.msg47306.html#msg47306

I originally wanted to be able to use the quill both manual and CNC driven.  That worked but there was backlash and could not get rid of it and
frankly that just sucks for CNC and backlash compensation leaves something to be desired.

So I redid it such that I could move the quill with almost zero backlash and a good resolution. I still can disconnect the ballscrew nut
and use it manually but frankly haven't done that in years.

There is thread in here about using the knee of the mill...do a search.

BTW, never ends does it!  :D
RICH
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 27, 2016, 01:48:50 PM
Thanks Rich,

So you had it first on the quill drive and then moved it to the quill direct? I have several good ideas coming in regarding strengthening the joint but all mean losing z travel and i can't do with any less of that.

I am looking at powering the knee instead - the attraction of 15 odd inches of Z axis is appealing but the big drawback is cost, i reckon i'd be looking at £600 at the end of the day with a big ball-screw, servo motor and drive, pulleys, extras etc. Maybe more if it needs a brake for when the power is off.

I'm drawn to splashing about £100 to see if driving the quill is a possibility or not.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 28, 2016, 02:19:29 AM
This seems a pretty neat way of backlash control - its a brake cable from a motorbike, one end is mounted to the quill and the other has an air cylinder on it with variable pressure.

The guy that fitted it also fitted a very tidy gear reduction system in the aluminium casing on the left, 15:1 ratio, double reduction.

He reports zero backlash and full quill travel :)

I think he had a small air receiver as well to provide a cushion effect.

On cost alone i feel it worth trying a drive from the left of the quill, topper the knee at any speed is going to take some time to save up for and its a big job to fit.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 29, 2016, 05:24:39 AM
Measuring on the existing adaptor from the Z screw to the quill, near the quill, I have well over 0.5mm of flex - thats a bad figure as it equates to backlash at the tool, so doing nothing here is not an option.

So, looking at the options -

Power the quill via the left side of the pinion shaft, this has slop in it so will need some clever way of preloading the quill upwards - this could lead to rapid rack/pinion wear as it will need enough preload to counter cutting forces from pulling the tool downwards.

Power the knee - this is an option but will cost a lot as it needs a ball-screw, servo, drive plus full tear-down to fit it all.

Alter what i have got - looking at the picture below, is there any harm in removing the web of metal circled?? It would mean i can get a bigger connecting arm in there with much more contact below the bolt to resist the down-forces, without losing any Z travel. Means stripping the head again.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 29, 2016, 11:02:44 AM
After some thought I reckon the easiest option based on what i have going already is to modify the quill housing and build a better connector arm - this should give more rigidity and still maintain the full Z travel.

In the attached picture, on the left is the existing setup, on the right is my next version - as you can see, in the existing one a lot of twisting moment is placed on the bolt when the arm is pushed down (heavy lines).

In the new version, the twist is converted to an axial pull on the bolt and the force transferred to the quill body via the longer contact face below.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on October 30, 2016, 12:45:21 PM
That was a long day!

Stripped the head, cut away the small web of cast at the bottom of the quill slot, altered the screw connector by welding on a 13mm thick bar underneath, the end of the bar was milled to the curvature of the quill before stripping, fitted up, refitted the Z drive and shimmed the connector, power head back on, motor back on, encoder back on, tested.

The connector now has an extra 25mm of contact below the quill bolt which is a massive improvement over the first attempt, this makes a big difference to the twisting effect on the quill bolt and is now far more rigid in the downward direction which is what matters.

Total backlash is now down from 0.6mm+ to 0.1mm and I also discovered that most of that backlash is caused by the BK screw block not clamping the screw correctly - this was always there but never spotted it before. I will strip that block and see whats wrong with it - either crap bearings or sleeves too short and the nut not reaching properly.

I don't think this one is getting any stiffer (ooh err!)  :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Robinson on October 30, 2016, 06:57:15 PM
Hi Dave,
I, years ago, put cnc on my ancient Henry Milnes knee type mill. When it came to the z direction I reckoned that the weight of the table,cross slide and knee (probably 250 lbs or more), would take care of any backlash in in the set-up so that I connected a fairly hefty stepper motor with a 3/1 stepdown that has worked perfectly for the last 6 years. It would be a very strong tool and motor that would lift any backlash into the system using the stepper onto the original windup on the mill and has proved to be troublefree, saving the expence and work of installing a new screw. Gravity wins!

another Dave.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on November 15, 2016, 12:17:47 PM
Steps-per or measured?

Considering I have ballscrews with a pitch of 0.2" or 5.08mm with a connection ratio of 2:1 and encoders with 10,000 pulses (all edges), should there be a reason to stray from a purely mathematical steps-per setting of 3937.00788 ??

I have no way of mapping the screw so measuring at one point seems like it could cause some variation at other points no?

Is it best to stick with calculated steps or try and measure using the axis calibrator??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Robinson on November 15, 2016, 03:19:27 PM
Hi Dave,
I have used the recommended method with the Mach 3 whereby you go to settings page, do a run, and check out what is with what should be and set up to suit. I have found in use that that is way easier to do and likely more accurate (at anyrate with my maths!). I have used this for several years without accuracy problems. Worth trying before you get knee deep in numbers.

cheers, Dave.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: dude1 on November 15, 2016, 03:55:25 PM
just use the auto feature but do big runs 4in or so it makes it a bit easyer and faster
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 09, 2016, 08:54:09 AM
Was there ever a fix or reason for the random "script compiler error in m3.m1s" issue?

Had it again today, first time in a fair while now, no idea why. Half way through a job, code starts with spindle not running because of the error but Mach happily runs the code regardless, bang goes the cutter :(

Restart Mach and all is good again as usual.

Why does Mach know there was an error - it puts the error message on screen - but happily runs on without the motor running?

No global error trap??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on December 09, 2016, 01:28:57 PM
Seems some people get that problem and others, like me, never do but now I have said that ::)

Anyway maybe adding this to your macropump would help, it should stop the machine if the spindle is 10% out from commanded speed.
http://www.machsupport.com/forum/index.php/topic,16290.msg110182.html#msg110182

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 09, 2016, 01:54:12 PM
Nice one, thanks Hood, that looks like a nice little fix.

Hope the plasma is running well ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on December 10, 2016, 03:25:50 PM
Hopefully it works for you Dave.

Plasma is cutting well although today I discovered the X axis is not right. Cut panels from 5mm Alu to make a water cooler tank for the tig and the X axis is short. On the 300mm x 300mm panels were only 295 or so on X.
Checked my steps per unit and they are correct  for 100mm per rev on rack and 10:1 on the gearbox so it looks like the gearbox is not exactly 10:1 like I thought. It can't be the rack/pinion as it is the same as on Y and it is spot on. Easy enough fix, just need to adjust the steps per unit.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 10, 2016, 03:56:37 PM
You mean after giving all the advice, you didn't do a steps calibration yourself ;) ;)

As you said, easy fix though.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on December 10, 2016, 04:02:05 PM
My advice is almost always to calculate rather than use the calibration utility :) Seems like this time it is not working out by calculating, either I just presumed the gearbox was a 10:1 or it says it is and it is not that accurate.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 18, 2016, 05:50:47 AM
Seems some people get that problem and others, like me, never do but now I have said that ::)

Anyway maybe adding this to your macropump would help, it should stop the machine if the spindle is 10% out from commanded speed.
http://www.machsupport.com/forum/index.php/topic,16290.msg110182.html#msg110182

Hood

Finally got round to adding this code in but then realised the high-speed spindle has no encoder so no feedback of real speed or lack of. :(

Maybe i need to look at a simpler fix like spindle power DRO = 0 after maybe 1s delay therefore spindle can't be running??

Not sure how to code a short delay, I guess i need to add some logic like "If M3/spindle is ON and PowerDRO=0 then fault" but needs a delay maybe to allow spindle to ramp up?

Would this be better added to the M3/M4 macros so "spindle start" -> "check spindle running" -> "ok or fail"

I will have a play when i summon the whatnots to go out in a cold shop and stand at a keyboard ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 18, 2016, 07:07:50 AM
Maybe as simple as this?

m3.m1s

DoSpinCW()

If GetDRO(1010) = 0 then ‘DRO1010 is spindle power meter
  msgbox “Spindle Failed To Start”
  Call DoOEMButton(1021) ’no spindle so go into reset
End if

Is it ok to add code to the m3/m4 macros?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on December 18, 2016, 02:45:09 PM
Not sure if that idea would work, ie putting it in the M3. Might be better having it in a custom macro and having your PP put it after the M3 in your code.
My reasoning is that if Mach decides the M3 macro has a compiler error then skips it it will likely do the same whether you have additional code in it or not.
If it is in a separate macro after the M3 then it should pick up when there is an issue.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 18, 2016, 04:15:28 PM
Hi Hood, good point.

Looking at it from the compiler fault view, maybe better in the macro pump after all, as a self contained monitor but if we suspect the m3 will not be called so no led's to monitor, what would it look at?

Just trying to find a way to avoid editing the PP if there is one. I have several code sources - sheet cam, fusion, vectric etc.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 19, 2016, 06:17:50 AM
When the cycle start button is pressed (2010 screen set) it turns green, is that a detectable change like an OEMLED etc?

Trying to find a way of knowing if code is supposed to be running or not without looking at spindle led's etc.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Hood on December 20, 2016, 03:20:41 AM
I am not sure if the macropump is the best place for this , I would be much happier personally with a custom macro.
Cycle Start LED does have an OEM, it is 804 if I recall.

Hood
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 20, 2016, 03:26:33 AM
Hmm, but if the compiler is kaput as it won't run the m3.m1s will it run the custom macro?

Would it even run the macro pump?

Maybe this is why nobody has trapped this intermittent bug??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 02, 2017, 02:30:07 PM
Hi all,

been a while since this thread ;)

For those who don't know, my Bridgeport was rebuilt with servos and larger motor, plus i added an auxiliary high speed spindle for aluminium work. The job in hand is shown in the pictures below, 5mm Aluminium, lots of holes and intricate features. I use 2mm single-flute and 5mm single-flute carbide tools for these.

Also, I already had built a custom mini-mill to make these (and learn CNC) and still have this, its currently up for sale but no takers yet. My reason for adding the aux spindle to the Bridgeport was two-fold - one to save space and two to make more use of the very expensive Bridgeport conversion.

Now, when doing the on the Bridgeport, I am seeing bad vibration or chatter on the tool, it appears to be vertical oscillation but tonight also suffered bad enough radial oscillation to break a 5mm tool ! When it goes into oscillation it makes you jump as its very noisy and you instantly know it will end badly either in poor finish or broken tooling.

So, something is not happy - my reservation is the spindle mount (shown below) - its canted out over to one side and although its clamped to the quill and into an R8 collet in the main spindle, it must be allowing deflection from the cutting forces.

Ok, so I have a bad situation, is there a way forward here?

Obviously I can take the dust-sheets off the mini-mill and carry on but I just don't have the space long-term and wanted to make more use of the Bridgeport as mentioned. I really want a one-size fits all solution here.

If I run the small tooling on the BP at 3000rpm (top whack) the run time per part-set will go from about 30minutes to several hours probably - feed rates go from 900mm/min to 25mm/min so i don't think thats an option - it needs more RPM's.

What can be done here guys???

One idea I quite like is to spin the ram on the BP around and build a custom Z-axis completely and mount where the BP slotting head normally sits. This could be built as heavily as desired with linear guides and a servo or stepper etc.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: RICH on February 03, 2017, 07:57:05 AM
Quote
What can be done here guys???
Just some thoughts..........


The holder for the high speed spindle looks to be rigid enough.
I would leave it alone for now.

Check the Holder:
Put an indicator on holder plate to measure the force of pushing with your finger on the holder out at the high speed spindle and see any rotation of holder about the Z and do the same for the pushing upwards. It should take a fair amount of force to see a measurable deflection. Fix the deflection problem if it exists.   

Check the spindle:
Check for any side and vertical play in the spindle. Should be no sideways
but you will probably have some vertical. I modified the hand / cable drive spindles I use. Needed to be carefull since there is expansion of the spindle as it warms at high speed. Some high end high speed spindles require that the spindle bearings be replaced after so much run time.
You may not be able to do any improvements and have what you have,but, t least you know that runout can accur if feeds, chip loads, loading, etc. can cause problems and need to adjust machining parameters.

Feed rate - Chip load etc:
First you may want to consider using a two flute high helix end mill rather than single flute as that can help with the chatter. STep over and cut depth will vary depending on material, feedrate etc. There are some guidelines to start but some experimenting is worth doing to find what works.
For quick range of machining paramters  there is an end mill chart in Members Doc's or use some of the manufacturers on site calaculators for quidence.

Good flooding of the end mill to assist in chip removal is required.

Oscillation / resonance can be discussed ( it can get complex quickly)
,BUT, it the above is looked at you may find you don't that type of problem to begin with.

Finaly........
Yeah, you want to get things done efficiently / quickly as possible but if the basics are out of whack to begin with you will have problems.Everthing is just a trade off.

RICH

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 03, 2017, 08:08:35 AM
Thanks Rich, I'll do some test/measurements this weekend.

The tool that broke was a 2-flute HH type, it was sent out by my supplier as a better option but didn't last long, about 10" of cut :) I was running at just below book specs which were 10,000rpm and 1000mm/min feed and 2.5mm DOC IIRC, I was running at 850mm/min, 2.5mm DOC.

Maybe I'm being too overzealous bye running hard? Maybe back off DOC some?? I just copied the settings i had on the mini-mill, but did not take into account the wobbly Z mount on the BP ?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 03, 2017, 09:21:53 AM
Hmmm,

Just been playing speeds & feeds for my single flute tool...

Manufacturer specs...
12k Rpm
2.5m DOC
1800mm/min feed - insane i think?

My previous settings...
12k rpm
2.5mm DOC
1000mm/min feed

F&S Calculator recomendations
12k rpm
1.8mm DOC
280mm/min feed - much lower ?

Maybe these lighter settings will be better?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 04, 2017, 10:20:07 AM
Ok, did some tests, first was to measure slack in the z axis at the adaptor in line with the high speed spindle - I have 0.02mm vertical (with reasonable force) and 0.15mm rotational around the quill - no doubt the source of my trouble.

Left cuts in the first picture below was at the feed recommended by my S&F calculator shown in the last post, 2 passes of 1.25mm ea, top cut is with me applying pressure to the motor while cutting to remove slack, the lower cut is with it running free as normal.

Both cuts look fine, no burr on the lip and pretty much perfect.

The right cuts in the first pic show results of a single 2.5mm DOC pass, same feed rate, again with hand pressure on the top pass and free on the lower.

Both cuts are acceptable this time but they show signs of vibration on the bottom surface - this is not an issue here as this tool is a roughing tool and will cut right through on these parts.

the second pic is just a closer view of the vibration on the second cuts.

Seems I just have to back off on the fast pedal a bit and let her do her thing, plus fit a bungee cord to remove the slop.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 27, 2017, 06:06:18 AM
Hi all, I'm getting that itch that can only be scratched by building something so I thought it time to revisit my mill build and fix some issues :)

Issue 1 - poor Z axis travel - avenue being explored = power the knee and feed tool length offsets to that thus retains full Z axis travel on the quill. Does anyone here have any help here - most of the stuff i have found on the 'net has lost all the media links or just get page missing errors. It will be a servo drive, belt reduction, probably best to go direct to the top of the screw rather than via the crank??

Looking for any tips here - software, macros etc

Thanks
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 27, 2017, 08:14:33 AM
Driving to the crank shaft seems the way in - simpler and as its only used for TL compensation which is all in the up direction, backlash should not be an issue, a member has forwarded some macros (thanks) and they seem to make sense.

I need to pull the covers off and check i have enough I/O on my CSMIO controller to take another axis and encoder plus limits etc

Seems do-able though.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 27, 2017, 09:09:27 AM
Managed to dig my way through the snow to the shop, pulled the cover off and happy to see I have no less than three spare axis/encoder inputs and plenty of I/O.

So glad I bought that CSMIO now, I love flexibility :)

Need to order up a servo and drive, probably go China way again, same guy on Aliexpress, couple of pulleys and a belt, good to go i think.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: garyhlucas on December 27, 2017, 05:16:55 PM
Issue 1 poor z axis travel.  Yep that is the one that makes a knee mill conversion really really suck.  Lots of time and money spent getting short drills, short holders, cranking the knee up and down. Used one for 4 years,  this time bought a bed mill.  For home my homebuilt mini mill has an 18” Z!
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 28, 2017, 03:29:28 AM
Yeah, its a real pain - i had to mix-n-match tool holders where possible which helped a lot but the big issue is the Haimer height probe - its the longest by far and really pushes the envelope if the job has short tools!

The Knee shift for tool length offset really sounds good and should help a lot for a very simple fix, cheap too.

I was toying with building from scratch, something like a Fadal VMC which has simple box frame maybe 1/2" wall steel box section, possibly epoxy granite filled, but my sums were not adding to anything that seemed worthwhile - too expensive for a risk project. Most of the money would have been in the steel frame, getting it machined true and some sort of heavy table. Once you get into £5000 plus its worth looking for old machines to rebuild rather than work up a new unknown one.

Would have been a nice project though :)

Have you got any pictures of your 18" Z mill??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 30, 2017, 04:56:20 AM
All parts on order :)

Still trying to get my head round how it all plays together but I gather tool length compensation is not really used as the knee sees the length difference and the code just thinks all tools are one length?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: garyhlucas on December 30, 2017, 12:41:19 PM
If you want to use the knee for tool length compensation the tool length would simply need to be passed to the knee axis to move it up or down by that amount BEFORE a tool is actually changed so you have room for it at your normal tool change Z height. Then the program sees all tools as the same length.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 30, 2017, 12:45:20 PM
Slowly making sense, thanks ;)

So in the code all tool length compensation would be turned off and I would likely be editing the M6 Start ??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: mc on December 30, 2017, 04:02:17 PM
If you want to use the knee for tool length compensation the tool length would simply need to be passed to the knee axis to move it up or down by that amount BEFORE a tool is actually changed so you have room for it at your normal tool change Z height. Then the program sees all tools as the same length.

You'd probably want to compare the two offsets, and only move if the new tool is longer, as you don't really want the knee cranking up for some short tool after running some long tool, before you've changed the tool.

Slowly making sense, thanks ;)

So in the code all tool length compensation would be turned off and I would likely be editing the M6 Start ??

That's actually a good question.
You still need to use tool length compensation, and use the tool lengths in the tool table to move the knee, but how does Mach handle that?
Not using compensation would work, if you know the knee will move to Z in the right position.
Other option is can mach combine the position of the knee, with the quill?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 30, 2017, 04:53:47 PM
I think the question of Mach combining both knee and quill was asked before and IIRC it can't.

One possible idea was to drop the knee in the M6start, do the change then lift the knee in M6end to its original position minus the new length, something like that anyway.

However i seem to recall bad issues with the CSMIO if there is any code at all in M6end, i should have made notes back then, i think it faulted out if there was any axis move while in the tool change routine if there was code in M6end.

On the mill its set for "Manual tool change" Does the "manual" bit i.e. the pause, come at the end of M6start and when you press return it runs M6end??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on December 31, 2017, 08:38:43 AM
Try this and see if it does what you want.

http://www.machsupport.com/forum/index.php/topic,13630.msg89523/topicseen.html#msg89523 (http://www.machsupport.com/forum/index.php/topic,13630.msg89523/topicseen.html#msg89523)


Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on December 31, 2017, 08:46:27 AM
Hi

thanks, that is the same guy that was helping on another forum :)

It his code i have pasted into my M6start


I started a new thread to keep things clearer :-

http://www.machsupport.com/forum/index.php/topic,36265.0.html (http://www.machsupport.com/forum/index.php/topic,36265.0.html)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 20, 2018, 11:24:20 AM
Made a little progress today, got the motor mounted...

(http://davekearley.co.uk/wp-content/uploads/2018/01/IMG_2062a.jpg)

Hopefully get the limit switches mounted tomorrow :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on January 21, 2018, 06:55:08 AM
Looking good.

What ratio are you looking to use? Is that an HTD belt?

Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 21, 2018, 08:23:56 AM
Yes HTD 5 x 15mm

IIRC it was 22/72 ratio - 3.2727:1
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 21, 2018, 08:39:14 AM
Got the limits and home switch fitted today, moving switches and fixed cams so I could do it all with two switches :)

Top is limit, bottom is home...

(http://davekearley.co.uk/wp-content/uploads/2018/01/IMG_2066.jpg)

Had to alter my plan of homing to top as with the vise fitted the bed will crash...

(http://davekearley.co.uk/wp-content/uploads/2018/01/IMG_2064.jpg)

All the way down, a lot of cranking....

(http://davekearley.co.uk/wp-content/uploads/2018/01/IMG_2067.jpg)

Wired the limit switch into the loop, just the home to take back to cabinet...

(http://davekearley.co.uk/wp-content/uploads/2018/01/IMG_2068.jpg)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 22, 2018, 02:16:55 PM
I'd forgotten how busy it was in the cabinet :)

(http://davekearley.co.uk/wp-content/uploads/2018/01/IMG_2069.jpg)

The knee axis servo drive will have go on the right-side wall i think.

Hopefully get the drive temporarily fitted tomorrow and powered up the day after.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 23, 2018, 01:29:08 PM
Ok, got it wired and powered up.

Little snag to start with, i'm a bit rusty here....

When you take Mach out of reset, the servo starts creeping without command, anyone give a pointer as to where i start digging??

It does not creep for long as you get an ePid fault.

Thanks :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on January 23, 2018, 03:18:28 PM
Hello,
had the same thing with this ePid fault.

i can see you are using CSLAB as well.

here the original answer from CSLAB as i went into this ePid Thing:

--- This fault can be activated by:
---  Bad Mach3 version. Bersions newer that 03.043.045 of Mach3 can cause ePID fault.
--- We recommend to use versions of Mach3 03.043.022 to 03.043.044. We always use 03.043.022 version as it's the most reliable in our opinion.


regards Tom

PS i "downgraded" to 03.043.022 and the ePid Thing is gone
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 23, 2018, 04:15:31 PM
Thanks, interesting, would be great to know what they did that an upgrade broke but i guess we'll never find out now.

I have the knee moving under power now, it was my fault for wiring the encoder to one channel and the analogue out to another channel ;)

Its not tuned right yet as it oscillates after it stops when homing.

At least we have motion now.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on January 23, 2018, 04:16:28 PM
Way to go Dave!


Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 23, 2018, 04:20:13 PM
Yes, i was pleased i sorted it - hate sleeping on a problem.

Its homing ok with the index pulse too.

Need to sort out soft limits, what sort of speed to limit it to, keyboard shortcut keys and so on.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on January 23, 2018, 04:45:12 PM
Hi Dave,
If you are driving the factory open bevel gears with the servo I would stay on the conservative side. Since it is only going to Home at the beginning and then just provide tool offsets it doesn't have to go 800 ipm!!! My guess that even 25 ipm will be tolerable and won't hurt anything. Typically on a standard keyboard I would use page up and down for the A axis and so I would suggest that insert and delete or home and end would work. Hopefully they aren't critical to the working of Mach.

Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 23, 2018, 04:53:05 PM
Ok, great its set on 500mm/min so i can go a little more if wanted i guess, it seems ok though at that speed.

I'm using a stainless kiosk keyboard which has a lot of keys missing (including all the F buttons :( ) I'll see what there is.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on January 23, 2018, 04:54:40 PM
I only use the "F" buttons when I am really upset! ROFLMAO
Sorry couldn't resist.

Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 23, 2018, 05:00:38 PM
LOL
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 24, 2018, 05:56:38 AM
Re the coordinates to use for knee moves?

My original idea was to have the C(knee) axis zeroed along with the Z axis so that when i use my Haimer probe to set work coordinates, the C and Z will both be reading zero, then when the next tool is called the macro can simply send the difference between my probe height and the tool height to the knee axis C.

Now, a learned friend has suggested a safer option is to use machine coordinates for the knee.

So, if its in machine coordinates, when i set the work zero ref (Z), the knee may be reading -250 or somewhere like that, now unless i get jiggy with variables and store the knee machine DRO when i press Z zero, how will i calculate the amount to move the knee upon tool change??

I may just not have seen the light yet but don’t know:)

It would certainly be safer to use machine coords of course.

IIRC variables are system wide so i can set one in the Z Zero call and read it later in the M6 macro's ??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 24, 2018, 09:08:17 AM
Ok, so i have a general dislike of going near variables - you have little idea of which one is free and i don't like cherry-picking a number just in case its used elsewhere and causes big trouble :)

So, my next idea to enable me to use machine coords for the knee is this...

Hide a user DRO on my screen somewhere,
Zero this DRO upon Mach loading,
When i press "Set Z Zero" it copies the value of OEMDRO(88) (C axis machine coords) into the hidden DRO - this is now my reference value for all TL calculations,
In my M6Start I can read the hidden DRO, use the value to calculate a move based on the difference between my probe and tool,
Make the move in G53 on the C axis

I'm guessing a test/abort/message will need going in the M6start to abort if the hidden DRO is zero i.e. Z is not set or a rapid dent of the knee could occur if a tool change is manually called etc.

Sound like a workable idea?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 24, 2018, 10:42:43 AM
Something like this maybe, I think I have it all working in Machine Coords for the C axis(knee) - it needs a hidden user DRO adding to the screen, unless we go down the variable route;)
Its not that long, I just like adding LOTS of text descriptors :)
Note - this code is UNTESTED


Code: [Select]
Sub Main()

If GetSelectedTool() = GetCurrentTool() Then Exit Sub ‘***Do nothing if current tool is called again

If GetOEMLED(1866) Then Exit Sub ***Ignore M6 calls LED

‘***Get the current G90/G91 state
CurrentAbsInc = GetOemLED(48)

‘***Get Axis Scale factors in use
XScale = GetOEMDRO(59)
YScale = GetOEMDRO(60)
ZScale = GetOEMDRO(61)
AScale = GetOEMDRO(62)

‘***Set All Axis Scales to 1
Call SetOEMDRO(59,1)
Call SetOEMDRO(60,1)
Call SetOEMDRO(61,1)
Call SetOEMDRO(62,1)
Sleep(250)

‘***Set the requested tool to be the current tool
tool = GetSelectedTool()
SetCurrentTool( tool )

‘***Switch to absolute distance mode
Code "G90"

‘***Move Z axis to machine zero - fully retracted for tool change
Code "G53 G0 Z0”
While IsMoving()
  Sleep 100
Wend

'========================================================================================
' Start of Knee Positioning Code
'========================================================================================
‘Get the knee reference position - set when pressing “Z Zero” at probing stage of setup
KneeRefPosition = roun(GetOEMDRO(1012)) ‘***This is a hidden DRO

‘***Get the respective backlash clearance allowance for downwards knee moves
If GetOEMLED(801) Then ‘***On  = English Measure INCH
    ClearAllow = 0.125  
Else                   ‘***Off = Metric Measure MM
    ClearAllow = 3.0    
End If

‘***Get the tool length whose offset number we are to use
‘***Tool has already been set to “currenttool” above
ToolOffsetNum = GetCurrentTool()

‘***Lookup the offset in the tool table, round it to 4 places, T100 is our 3d Haimer Probe
ToolOffset = roun(GetToolParam(ToolOffsetNum, 2))
ProbeOffset = roun(GetToolParam(100, 2))

‘***Calculate the difference between the probe and the new tool - can be negative or positive
OffSetDifference = ProbeOffset-ToolOffset

‘***See where the knee is now in machine coordinates
CurrentKneePos = roun(GetOEMDRO(88))’***Mach C Axis DRO
  ‘Message "CurrentKneePos=" & CurrentKneePos & " OffsetDifference=" & OffsetDifference ‘***Use this line for debugging

‘***Calculate the new knee machine coordinate value based on tool length difference
TargetKneePosition = KneeRefPosition - OffsetDifference

  ‘Message “Target Knee Pos = " & TargetKneePos ‘***Use this line for debugging

‘***If the knee is currently higher than it needs to be, we first
‘***move it down, to ensure the final move is always UP.  This ensures
‘***backlash is taken out, and provides more consistent positioning.
If TargetKneePosition > CurrentKneePosition Then
  Code “G53 G0 C“ & (TargetKneePosition + ClearAllow)
  While IsMoving ()
    Sleep 100
  Wend
End If

‘***Now move the knee UP to its final position
Code “G53 G0 C“ & TargetKneePosition
While IsMoving ()
  Sleep 100
Wend

'========================================================================================
' End of Knee Positioning Code
'========================================================================================

‘***If G91 was in effect before then return to it
If CurrentAbsInc = 0 Then
  Code "G91"
End If

‘***Put previous Axis Scale factors back
Call SetOEMDRO(59,XScale)
Call SetOEMDRO(60,YScale)
Call SetOEMDRO(61,ZScale)
Call SetOEMDRO(62,AScale)
Sleep(250)

End Sub
  
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 24, 2018, 04:20:49 PM
Couple of small errors in that code, fixed now - i'm calling axis scale factor DRO for A axis but i'm using C axis  and i called my hidden DRO an OEMDRO where it should be UserDRO I think.


So, presuming this code mostly works, if i check OEMLED(812) (C Ref Led) a value of 1 would indicate if the knee has been homed yes?
My reason is so that i can abort the tool change macro somewhere as it could be dangerous unless the knee is homed and its exact position known.

Is it worth also zeroing my UserDRO when the knee is homed - a latent value in this DRO could be dodgy if it was from a previous job, I can check for a zero value in the macro and abort.
Maybe also zero the UserDRO when the LoadFile button is pressed?

I'm just trying to look for pitfalls before they happen and possibly building the fix in - seems there can be quite a lot can go wrong when you have mixed length tools and the knee going up and down along with the Z axis etc :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 25, 2018, 05:09:49 AM
Ok, major changes below, my learned friend and mentor has enlightened me to a simple way by just comparing old and new tools, seems to make more sense now and needs no DRO's adding etc.

I have also made the last 3mm of move at F100 rather than G0 all the way so it gives the best chance of hitting the spot.


Code: [Select]
Sub Main()

If GetSelectedTool() = GetCurrentTool() Then Exit Sub ‘***Do nothing if current tool is called again

If GetOEMLED(1866) Then Exit Sub ***Ignore M6 calls LED

‘***Get the current G90/G91 state
CurrentAbsInc = GetOemLED(48)

‘***Get Axis Scale factors in use
XScale = GetOEMDRO(59)
YScale = GetOEMDRO(60)
ZScale = GetOEMDRO(61)
CScale = GetOEMDRO(64)

‘***Set All Axis Scales to 1
Call SetOEMDRO(59,1)
Call SetOEMDRO(60,1)
Call SetOEMDRO(61,1)
Call SetOEMDRO(64,1)
Sleep(250)

‘***Get old tool length
OldToolLength = roun(ToolLengthOffset)

‘***Set the requested tool to be the current tool
SetCurrentTool(GetSelectedTool())

‘***Get new tool length
NewToolLength = roun(ToolLengthOffset)

‘***Switch to absolute distance mode
Code "G90"

‘***Move Z axis to machine zero - fully retracted for tool change
Code "G53 G0 Z0”
While IsMoving()
  Sleep(100)
Wend

'========================================================================================
' Start of Knee Positioning Code
'========================================================================================
‘Get the knee position in machine coordinates
CurrentKneePosition = roun(GetOEMDRO(88))

‘***Get the respective backlash clearance allowance for downwards knee moves
If GetOEMLED(801) Then ‘***On  = English Measure INCH
    ClearAllow = 0.125 
Else                   ‘***Off = Metric Measure MM
    ClearAllow = 3.0   
End If

‘***Calculate the knee machine move value based on tool length difference
If OldToolLength > NewToolLength then ‘***We need to RAISE the knee
    Message “Knee Will Lift ” & OldToolLength - NewToolLength ‘***Use this line for debugging
    Code “G53 G0 C” & (CurrentKneePosition - (OldToolLength - NewToolLength)) + ClearAllow
    While IsMoving ()
      Sleep(100)
    Wend
    Code “G53 G1 C” & (CurrentKneePosition - (OldToolLength - NewToolLength)) & “ F100”
    While IsMoving ()
      Sleep(100)
    Wend
End If

‘***If the knee is currently higher than it needs to be, we first
‘***move it down, to ensure the final move is always UP.  This ensures
‘***backlash is taken out and provides more consistent positioning.

If OldToolLength < NewToolLength then ‘***We need to LOWER the knee
    Message “Knee Will Lower ” & NewToolLength - OldToolLength ‘***Use this line for debugging
    Code “G53 G0 C” & ((CurrentKneePosition + (NewToolLength - OldToolLength)) + ClearAllow
    While IsMoving ()
      Sleep(100)
    Wend
    Code “G53 G1 C” & (CurrentKneePosition + (NewToolLength - OldToolLength)) & “ F100”
    While IsMoving ()
      Sleep(100)
    Wend
End If

If OldToolLength = NewToolLength then
    Message “Knee Will Not Move” ‘***Use this line for debugging
End If

'========================================================================================
' End of Knee Positioning Code
'========================================================================================

‘***If G91 was in effect before then return to it
If CurrentAbsInc = 0 Then
  Code "G91"
End If

‘***Put previous Axis Scale factors back
Call SetOEMDRO(59,XScale)
Call SetOEMDRO(60,YScale)
Call SetOEMDRO(61,ZScale)
Call SetOEMDRO(64,CScale)
Sleep(250)

End Sub
   
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on January 25, 2018, 06:39:32 AM
Looking good.
Keep up the good work.


Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 25, 2018, 01:19:30 PM
Hmm, after spending an hour trying to figure out why it does nothing, i filled it with msgbox calls to examine why

"ToolLengthOffset" seems to do nothing at all and returns zero, this is why the macro failed.

what is the correct way to get tool length offset???

Title: Re: Bridgeport Knee Mill Conversion?
Post by: Overloaded on January 25, 2018, 01:37:58 PM
 ???
page 28-29

GetTooParam
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 25, 2018, 01:49:51 PM
Just found it, thanks.

Was reworking it with this method as you replied...

NewToolLength = roun(GetToolParam(GetCurrentTool, 2))
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 25, 2018, 02:41:43 PM
 :D ;D :D ;D

This code version works perfectly, it's one impressive addition to the mill, just increased it's usability 200% I think, she's now got 350mm of Z clearance under code control  8)

Of course, with every new feature there are new ways to mess things up of course -
do not enter a new tool manually in the "Current tool" DRO,
do not jog the knee manually once you have ref'd the Z axis and set the first tool or probe,
always enter the 1st tool/probe manually in the current tool DRO
probably a million other ways to make balls-up :)

I think a good addition will be to add some code to check that the new knee position is still a negative number as the axis runs out of travel at zero :)

One thing that did fail is the Index Homing on the knee - keeps throwing "Index not within allowed distance" error which means the index pulse is out of range, will have read the manual on this one.


Code: [Select]
Sub Main()

If GetSelectedTool() = GetCurrentTool() Then Exit Sub ‘***Do nothing if current tool is called again

If GetOEMLED(1866) Then Exit Sub ***Ignore M6 calls LED

‘***Get the current G90/G91 state
CurrentAbsInc = GetOemLED(48)

‘***Get Axis Scale factors in use
XScale = GetOEMDRO(59)
YScale = GetOEMDRO(60)
ZScale = GetOEMDRO(61)
CScale = GetOEMDRO(64)

‘***Set All Axis Scales to 1
Call SetOEMDRO(59,1)
Call SetOEMDRO(60,1)
Call SetOEMDRO(61,1)
Call SetOEMDRO(64,1)
Sleep(250)

‘***Get old tool length
OldToolLength = roun(GetToolParam(GetCurrentTool, 2))

‘***Set the requested tool to be the current tool
SetCurrentTool(GetSelectedTool())

‘***Get new tool length
NewToolLength = roun(GetToolParam(GetCurrentTool, 2))

‘***Switch to absolute distance mode
Code "G90"

‘***Move Z axis to machine zero - fully retracted for tool change
Code "G53 G0 Z0”
While IsMoving()
  Sleep(100)
Wend

'========================================================================================
' Start of Knee Positioning Code
'========================================================================================
‘***Get the knee position in machine coordinates
CurrentKneePosition = roun(GetOEMDRO(88))

‘***Get the respective backlash clearance allowance for downwards knee moves
If GetOEMLED(801) Then ‘***On  = English Measure INCH
    ClearAllow = 0.125 
Else                   ‘***Off = Metric Measure MM
    ClearAllow = 3.0   
End If

‘***Calculate the knee machine move value based on tool length difference
If OldToolLength > NewToolLength then ‘***We need to RAISE the knee
    Code “G53 G0 C” & (CurrentKneePosition - (OldToolLength - NewToolLength)) + ClearAllow
    While IsMoving ()
      Sleep(100)
    Wend
    Code “G53 G1 C” & (CurrentKneePosition - (OldToolLength - NewToolLength)) & “ F100”
    While IsMoving ()
      Sleep(100)
    Wend
End If

‘***If the knee is currently higher than it needs to be, we first
‘***move it down, to ensure the final move is always UP.  This ensures
‘***backlash is taken out and provides more consistent positioning.

If OldToolLength < NewToolLength then ‘***We need to LOWER the knee
    Code “G53 G0 C” & (CurrentKneePosition + (NewToolLength - OldToolLength)) + ClearAllow
    While IsMoving ()
      Sleep(100)
    Wend
    Code “G53 G1 C” & (CurrentKneePosition + (NewToolLength - OldToolLength)) & “ F100”
    While IsMoving ()
      Sleep(100)
    Wend
End If

If OldToolLength = NewToolLength then
    ‘Message “Knee Will Not Move” ‘***Use this line for debugging
End If

'========================================================================================
' End of Knee Positioning Code
'========================================================================================

‘***If G91 was in effect before then return to it
If CurrentAbsInc = 0 Then
  Code "G91"
End If

‘***Put previous Axis Scale factors back
Call SetOEMDRO(59,XScale)
Call SetOEMDRO(60,YScale)
Call SetOEMDRO(61,ZScale)
Call SetOEMDRO(64,CScale)
Sleep(250)

End Sub
   
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 25, 2018, 04:54:47 PM
One more - make sure you don't have any G43 active - i modified the post processor to always output G43 H0 for any tool, having TL comp active as well as knee comp could be good fun :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 26, 2018, 04:33:01 AM
Ok, lets try this flavour - it uses a hidden DRO or a #Var to store the position of the knee when the Z axis is referenced to work zero.

Its a much safer version i think as i can then move the knee anywhere i want anytime and it still knows where to go in the M6 routine.



Code: [Select]
Sub Main()

If GetSelectedTool() = GetCurrentTool() Then Exit Sub '***Do nothing if current tool is called again

If GetOEMLED(1866) Then Exit Sub '***Ignore M6 calls LED

Tool = GetSelectedTool()'***Set the requested tool to be the current tool
SetCurrentTool(Tool)

Code "G53 G0 Z0" '***Move Z axis to machine zero - fully retracted for tool change
While IsMoving()
  Sleep(100)
Wend

'***Get the respective backlash clearance allowance for knee moves
If GetOEMLED(801) Then '***On  = English Measure INCH
  ClearAllow = 0.125  
Else                   '***Off = Metric Measure MM
  ClearAllow = 3.0    
End If

'***Lookup the offset in the tool table, T100 is our 3d Haimer Probe
ToolOffset = GetToolParam(GetCurrentTool(), 2)
ProbeOffset = GetToolParam(100, 2)
OffSetDifference = ProbeOffset-ToolOffset'***Calculate the difference between the probe and the new tool - can be negative or positive

'***Calculate the new knee machine coordinate value based on tool length difference
KneeRefPosition = GetUserDRO(1012) '***Get the knee ref position - set when pressing "Z Zero" at probing stage, this is a hidden DRO
TargetKneePosition = KneeRefPosition - OffsetDifference

'***Rapid to a position lower than needed to allow for a final slow move up
Code "G53 G0 C" & (TargetKneePosition + ClearAllow)
While IsMoving()
  Sleep(100)
Wend

'***Now move the knee UP slowly to its final position
Code "G53 G1 C" & TargetKneePosition & " F100"
While IsMoving()
  Sleep(100)
Wend

End Sub
      
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 26, 2018, 06:44:08 AM
Just to check my sanity with the new method I hacked up a little demo in VB6, one of my favourite apps, it uses the same calculations and variables as the macro will and shows the result with two sliders representing the knee/bed  ;) ;)

(http://davekearley.co.uk/wp-content/uploads/2018/01/IMG_2078.jpg)

Works perfectly, now just have to decide to go with hidden DRO or user variable.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: olf20 on January 26, 2018, 06:57:23 AM
I too have a knee mill. I'm no way close to what you
guys do. I really like following your project. Just little
tid bits gives me idea's that makes my life just a little
easier.
Great job!!
Following;
olf20 / Bob
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 26, 2018, 07:00:34 AM
Its good fun :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 27, 2018, 07:39:51 AM
The new macro works nicely, i went with a #var in the end (179) as i believe the low numbers 100-199 are not persistent?

Some rough videos...

Messing with tools...
https://youtu.be/npuQk2Ao7UY (https://youtu.be/npuQk2Ao7UY)

Z axis repeat homing...
https://youtu.be/sGrpzJVhkSk

Y axis repeat homing...
https://youtu.be/fLXJXyGhipw

X axis repeat homing...
https://youtu.be/SUt1NiHZYIg

C axis repeat homing...
https://youtu.be/55VjHRgzt9s

Can't really ask for better i think from an old manual Bridgeport converted to CNC :) :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 27, 2018, 08:24:14 AM
Ok now the first issue....

works ok manually as in the video and my trials this morning.

I put a code file on it, the front plate for my knee axis drive, nice simple job, 4 tools.

Set my Haimer probe in the Current tool box as before, set tool 100, set my references to zero.

Run code and get "Softlimit warning" on Z min, presumed it was confused with the new knee offsets maybe so chose to override the warning and with hand over e-stop watched as the knee lifted nicely, motor started then the Z axis ploughed happily into the work, e-stopped in time to stop damage apart from a scratch where the collet chuck touched the surface.

So, clearly I have goofed up and my first thoughts are the G43's in the file. I am confused here as to exactly what is needed - I first thought that having TC/G43 in the file will apply TC AS WELL as the knee having moved = crash or miss completely.

Now I have it set as G43 H0 as i read that H0 was the same as not having G43 so should be safe - Am i wrong??

The post was modified to output H0 regardless.

I cant think of any other reason for the tool to plunge to the work way past the Z call depth which was Z25 and i e-stopped at Z-170 odd.

Heres the code start...

Code: [Select]
(KNEE MOUNT FRONT PLATE)
(T3  D=6. CR=0. TAPER=90DEG - ZMIN=-2. - CENTER DRILL)
(T10  D=6.1 CR=0. TAPER=118DEG - ZMIN=-12. - DRILL)
(T11  D=8. CR=0. - ZMIN=-11. - FLAT END MILL)
(T15  D=10. CR=0. TAPER=45DEG - ZMIN=-1.5 - CHAMFER MILL)
N10 G90 G94 G91.1 G40 G49 G17
N15 G21
N20 G53 G0 Z0.
N25 G90

(END FACING)
N30 M5
N35 M9
N40 T11 M6
N45 S3000 M3
N50 G54
N55 M7
N65 G0 X-1.02 Y-4.706
N70 G43 Z25. H0
N75 Z2.
N80 G1 Z-10.2 F500.

H0 can only be zero right?
Really confused now - any ideas??

I'm gonna nip out and try deleting the G43 line altogether...
Title: Re: Bridgeport Knee Mill Conversion?
Post by: olf20 on January 27, 2018, 08:43:41 AM
In one of your videos I see you have a modified
screen set with a large tool path display. Any
advise on how to accomplish. I have done some
mods to my 1024 display.
Thanks
olf20 / Bob
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 27, 2018, 08:44:44 AM
Hi this is the 2010 screen set from Ger21 on here. :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 27, 2018, 08:49:04 AM
I think i have found the culprit - G54 work offset.

I modified the "Zero Z" button from a system function of "Zero Z" to a macro call.

In the macro i have used DoOEMButton(1010) which i presumed was the zero call, it does zero the DRO but leaves the G54... values in place.

Anyone know what button call would zero ALL the Z axis work offsets?? I always use the probe to set Z zero and never apply a work offset to that axis.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 27, 2018, 09:15:37 AM
Its not G54.

Something somewhere is modifying the z axis.

I called T100, set the probe, zeroed my Z axis and the knee ref
Then checked the G54 and that had the correct offset in it for the z zero
Next i called T11 which is shorter, the knee lifted correctly to compensate
Then pressed start (no tool fitted) and the z plunged happily off the scale and i hit stop.
Look back at current tool pro and it showed T11 correctly but the Z axis was about 100mm off - the code was calling Z2.0 but Z2 is way off below where it can go as the numbers are so way off.

Now, i am only using #var 179 and i don't think that is connected with Z DRO at all, calling button 1010 in my Z zero macro seems to set things correctly.

I'm at a  loss now as to what is going wrong, is it possible the T11 M06 call is applying tool offset internally somehow even though i have deleted ALL G43 lines from the code???

Something is messing with the Z dro I think,

Stuck now. :(
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 27, 2018, 09:19:30 AM
Its not G54.

Something somewhere is modifying the z axis.

I called T100, set the probe, zeroed my Z axis and the knee ref
Then checked the G54 and that had the correct offset in it for the z zero
Next i called T11 which is shorter, the knee lifted correctly to compensate
Then pressed start (no tool fitted) and the z plunged happily off the scale and i hit stop.
Look back at current tool pro and it showed T11 correctly but the Z axis was about 100mm off - the code was calling Z2.0 but Z2 is way off below where it can go as the numbers are so way off.

Now, i am only using #var 179 and i don't think that is connected with Z DRO at all, calling button 1010 in my Z zero macro seems to set things correctly.

I'm at a  loss now as to what is going wrong, is it possible the T11 M06 call is applying tool offset internally somehow even though i have deleted ALL G43 lines from the code???

Something is messing with the Z dro I think,

Stuck now. :(


Edit...
No it didn't, just thinking here, G54 in Z zero would be the distance from Z machine zero to the work zero??
Well its not, G54 was reading something like 190mm when the actual distance was something like 40mm

Does setting Z zero internally apply TLC to the G54 offset??
That might explain it if it did??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 27, 2018, 09:22:23 AM
I also cant see why it works ok in manual calls with no code loaded (see video) but fails when in code mode????
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 28, 2018, 05:57:09 AM
Ok, i'm getting closer :)

It seems if i call all tools my the MDI it works, but will verify this with a repeat TC code program in a minute.
When you call a tool by MDI using M6T100 the Z DRO does NOT change.

Now, before i always set my Haimer probe by typing 100 in "Current Tool" DRO on the 2010 screen-set - do this and the Z DRO gets TLC applied to it - this is the cause of my issues i think, looks like the "Current Tool" DRO runs G43 H********* when you press enter on it - thus the cause of my lost Z travel.

I'm off to run some more tests but it feels like I will have to remove the "Current tool" DRO for safety reasons and do it all MDI, no biggy.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 28, 2018, 06:26:37 AM
Nope, failed again :(

I manually ran through my whole tool rack, 20+ tools using MDI TxxM6 G0Z0 and every time it worked perfectly 100% tool on the TOM.

Loaded up the code, soft limit on Z Min warning, bypass, crash(e-stopped to avoid) The Z axis just dives.

Here is the screen after i stopped - the Z axis is at +85 and the code is calling for Z2 ??
(http://davekearley.co.uk/wp-content/uploads/2018/01/IMG_2087.jpg)

The Offsets screen...
(http://davekearley.co.uk/wp-content/uploads/2018/01/IMG_2088.jpg)

The Z of 186mm is about right - i had the z at about +30 when zeroing with the Haimer which is about 150mm long.

So, i'm stuck again - it works well in manual but can't run code :(


Have attached the exact code file below.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 28, 2018, 06:59:44 AM
Probably digging myself in deeper here but could it be how i have my tool table setup?

I measure all my tools in a height-setter which feeds the result straight back to Mach TT, all tools have a height including the Haimer probe.

Now, i just went back and put the probe back in the spindle, and the Z was off by exactly the height of the probe - this is why it crashes.

BUT why only in code and not manual - it works perfectly in manual.

So confused now.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on January 28, 2018, 07:11:13 AM
hi,

is it possible that your are doing th TLC twice ?

1. with the c-axis (knee)
2. SetCurrentTool(Tool) (m3 internal TLC)

just thinking while i went through your post's.

Thomas
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 28, 2018, 07:15:11 AM
I was unaware what setcurrenttool actually did - that may be a lead there, thanks.

If i leave setcurrenttool out, any idea what would happen??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on January 28, 2018, 07:22:35 AM
do a little test to see what Setcurrenttool does.


-load 1024.set
-put in the tooltable  height 10.0 for tool1
-enter tool 0 in the tool Information dro
-push zerro z button
-enter tool 1 in the tool Information dro
-watch z coordinates

Thomas
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on January 28, 2018, 07:25:38 AM
If i leave setcurrenttool out, any idea what would happen??

i think, as far i have walked through your code,it will work like you expected,
because the TLC is done by your c-axis.

Thomas
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 28, 2018, 07:27:22 AM
That was my conclusion, off to try as soon as i stuff this sandwich down :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 28, 2018, 08:40:29 AM
If i leave setcurrenttool out, any idea what would happen??

i think, as far i have walked through your code,it will work like you expected,
because the TLC is done by your c-axis.

Thomas


NAILED IT!

Well spotted, TPS,

removed the Setcurrenttool line and it all fell into place :)

You can use the "Current tool" DRO anymore as it has no idea what the current tool is but i can live with that, i guess it could be fixed by adding a line to the macro that sets a pseudo current tool DRO on =screen to show the last selected tool call.

But its all working, part made, no mess ups.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 28, 2018, 09:13:07 AM
I've now split the code - the M6Start drops the knee 50mm to make tool change easier when going from short to long, the M6End then does the calculations and sends the knee where it needs to go.

It's conservatively set at 400mm/min at present, i couldn't see the point of working the bevel gears too hard, time is not my enemy on machines.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on January 28, 2018, 01:35:22 PM
glad to read, that i was able to set the "correct Trigger".  ;)

Thomas
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 28, 2018, 01:40:52 PM
glad to read, that i was able to set the "correct Trigger".  ;)

Thomas

Not as glad as i am ;)

That line was there when i started so i presumed it was some sort of vital Mach jiggery-pokery and left it there - proves what they say about presumption ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on January 28, 2018, 01:44:30 PM
I measure all my tools in a height-setter which feeds the result straight back to Mach TT, all...

would be interested, how you do this, could you please describe.

Thank you Thomas
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 28, 2018, 01:57:50 PM
Ooh, thats a way back, pretty certain its in this thread though.

I have an encoder, a basic linear way(nylon block in channel) the encoder connects to a 2.5mm pitch belt in a loop, along the loop is connected an angle bracket facing an R8 socket.

The encoder is connected to an ENC module for the CSMIO, Mach3 has a macropump macro that looks at the input from this encoder and displays it on my screen-set, real-time. The screen has a "Zero" button and a "Set" button. The angle is lowered onto the socket on the setter, zero is pressed and the tool fitted, angle is lowered onto the tool tip and "Set" is pressed - this copies the encoder DRO to the tool table and then shows the table so you can give it a name etc.

Takes seconds to do, you can load tools in the middle of code if you forgot one or break one etc. The actual "height" displayed is irrelevant, its in an R8 socket which always locates on a set part of the taper just as the spindle does, the Haimer probe i use for TOM setting is also measured and entered - all my work is relative to this "tool".

The only cost was for the ENC module, the rest is all junk-box bits. It was a fun project basically, but quite useful.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on January 29, 2018, 01:43:28 AM
thank you fore the Information,
Looks like to be my next Little Project, after the retrofit of my TongIl TNV40 is finished.

Thomas
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 29, 2018, 01:49:23 PM
5min video of a simple part run-through on the mill. Uses 6 tools: centre, 8mm drill, 5.4mm drill, 10mm mill, chamfer, M6 tap.

Its only air-cutting - the Z zero is 50mm above bed just for video. No fine tuning has been done yet, the bed drops 50mm to change tools but may get away with less etc.
Seems to work very nicely I think :)

https://youtu.be/5YkC6-ewrHE (https://youtu.be/5YkC6-ewrHE)

Since doing the video I have upped the main spindle to 4000rpm/133Hz on the VFD, opinion seems to be that it'll be ok at that as its not too far above original speed.
Surprisingly, at that speed, the power meter shows it takes 48% or 1.4Hp just to run the fan and turn the spindle!
Might be worth taking the fixed fan off and fitting a pancake fan on top.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: olf20 on January 30, 2018, 06:46:26 AM
Looks great Dave! You will have to start another
project. I really like following your mods.
olf20 / Bob
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 30, 2018, 06:48:13 AM
LOL, not much left to modify now :(

I do have a plan on the back-burner for an ATC on the mill but its a way off yet.

I want to make another control panel for the mill - the one made is nice and ergonomic with its slant keyboard etc but it makes a great chip collector :(  Need a vertical KB i think.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on January 30, 2018, 04:47:41 PM
Or chip control!!!!!!
Try one of the rubber roll up keyboard they are immune to chips.


Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on January 31, 2018, 02:07:47 AM
I could try chip control but i cant think of any system that would work apart from a massive enclosure that will not detract the bonus of having a fully open flexible knee mill :) Its got more travel than many VMC's do, a much longer bed at 48" and i sometimes hang stuff over or off the sides ")

Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on January 31, 2018, 07:04:12 AM
I have seen a shower curtain and rectangular curtain rods used to good effect.
Inexpensive, disposable and removable in about 10 seconds.


Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 01, 2018, 04:32:23 AM
Learn something every day.

Been messing around with a project, engraved aluminium signs, test subject is 360x80mm.

Testing two setups in Fusion - on the Bridgeport standard and on the high speed head.

Standard has 4 tools reducing in size from 8mm to 1.5mm
High speed has two tools - 5mm and 2mm

Fusion was giving simulation times of 2.34hrs for standard and 2.35 for high speed with ramps, i changed the ramps to plunges and times dropped to 1.18 and 1.20 so a massive waste on ramping down.

I need to check these figures out because it would indicate that i do not need a high speed head at all as the old BP is faster (at 4000rpm) Very odd indeed. I know i reduced the rates on the high-speed as its not 100% rigid being canted out from the spindle but if its the same end result i would be better off using the BP spindle as i have repeatable tooling mount then so no repeated touch-offs.

I'm not sure how successful a 1.5mm three flute HsCo tool will be on the old girl but i have a box of them so can try it :)

Need to crunch my numbers again in HSMAdvisor. Can it be just as simple as faster but less feed-rate due to rigidity vs slower but more aggressive cuts????
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on February 01, 2018, 06:42:11 AM
It is all about the MRR. Whatever gets the most material removed in the shortest time assuming the end product is usable.


Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 01, 2018, 06:50:36 AM
Clearly a lot to learn.

I just tried a 2d Adaptive path with HSM speeds, processing time went up to 2.30hrs for just the first tool (5mm) with thousands of retracts etc, would be hard on the machine i think. Picture attached.


Title: Re: Bridgeport Knee Mill Conversion?
Post by: olf20 on February 01, 2018, 07:51:35 AM
Can you use a roughing tool path, then do the cleanup.
I do this with aluminum projects all the time. I'm making
some award medallions for my grandson. Roughing 1/4 em
then 1/8 for finish and cutout.
olf20 / Bob 
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 01, 2018, 07:58:23 AM
Ah, so you say go for standard path on roughing then 2d adaptive on the cleanup tools??

I'll have a play.....



Edit, nope, 2d adaptive does not have "rest" machining so spends hours cutting air :)

I never thought a simple job would have so many variables.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Overloaded on February 01, 2018, 08:38:28 AM
Very nice job on the mill conversion Dave, I'm envious of your commitment and dedication.
Also, thanks for prompting me to research Adaptive strategies, namely this in-depth explanation of Adaptive Clearing.

https://nexgencam.com/hsm-tips-tricks/item/understanding-hsmworks-adaptive-clearing-toolpaths

Thanks again,
Russ
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 01, 2018, 08:54:55 AM
Thanks for the compliment Russ,

I'm only scratching the surface in Fusion. I'll have to print that link as they have done the page in white on black and i can't read that, gives me bad headaches, looks good though.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 02, 2018, 05:58:14 AM
Hmm, this little tester is teaching all sorts of things :)

I change tools to two-flute aluminium ones and stuck to my slower BR head at 4000 rpm, machining time is now down to a staggering 23minutes plus tool-changes

I went for 10mm to hog the bulk out, then Rest machining with 5mm, 3mm, 1.5mm - I think that gives a good step-down in tools, adding the 3mm really took the time down.

Now, what i cant figure out is why not all the letters get machined - two pictures attached, one shows the path on a letter "a" with the 3mm tool, the gap is shown in the last picture at over 2mm but the 1.5mm tool refuses to go there so the gap is left joined?

There is no finishing allowance - all paths are to final size.

Any ideas???
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on February 02, 2018, 06:04:59 AM
If your step over plus your tool diameter is greater than the space between features then it will not go through that apace..


Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 02, 2018, 06:35:48 AM
Hmm, baffled now, i presumed it would be slotting that gap?

Just tried reducing the step over to 0.43 and full depth (2mm) and it makes no difference.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 02, 2018, 06:43:24 AM
It does not look like its connected with step over - the 1st tool is 10mm and it happily passes through a 10.15mm gap.

One big difference is that the 1st path is standard, the others are "rest" machining????

In fact its worse than i thought, there is a lot of unmachined area, see the "u" in the picture attached - it just cuts two small areas inside and leaves the rest.??

That would explain the short run time a bit.

Very odd
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 02, 2018, 07:35:58 AM
Ok, i'm clearly not getting this ;)

It seems i need to be using 3d Adaptive paths, these have rest machining as well.

Tried that and as the tools get smaller it adds an ever increasing workload of finer and finer paths where it tries to perfect the previous path, this adds hours to the time so is pointless.

Trawl the 'tube and mr NYCNC had it but "fixed" it by making stock-to-leave+tolerance bigger on each tool - this may work for two tools but i have 4 and by the time it gets to T4 i am leaving 0.43mm of stock - this means too much for a cleanup pass with the 1.5mm tool at the end.

Baffled now, i did not think this would be so advanced.


Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 02, 2018, 09:28:45 AM
Ok, never mind, i'm binning this project as i've spent far too long on it and got nowhere :(

I also see some of the letter spacing is too close for a 1.5mm tool but there is no way in F360 to adjust that and importing text into F360 is full of bugs too. Clearly not the app for engraving even if it is "mill" engraving.

I might have a play with aspire but have to fix a new post as that app is tuned for my high-speed setup.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on February 02, 2018, 09:34:45 AM
if you post your drawing,
i will put it through my estlcam and see what happens.

Thomas
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 02, 2018, 09:41:03 AM
if you post your drawing,
i will put it through my estlcam and see what happens.

Thomas


Here you go, thanks
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on February 02, 2018, 09:53:41 AM
can you Export this to stl ?
estlcam does not suppurt Fusion files.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 02, 2018, 10:02:33 AM
Hi

it does .step or .iges not .stl

Also the fusion servers are down now, cant export so will try later if either of those types are usable??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on February 02, 2018, 10:32:46 AM
here:

https://forums.autodesk.com/t5/fusion-360-design-validate/how-to-export-to-stl/m-p/6340331#M56468

i found something how to get a stl file.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 02, 2018, 10:49:59 AM
Hmm, tried that and it just made the model disappear - saved nothing.

Now Fusion is crashed again, I dont think its a "Fusion" day today, the servers are down and the app just refuses to work offline.

I will look tonight if servers are back up
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on February 02, 2018, 05:57:21 PM
Hi

it does .step or .iges not .stl

Also the fusion servers are down now, cant export so will try later if either of those types are usable??

This is why I don't want any of my machining stuff in the cloud.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 03, 2018, 02:52:56 AM
That is my one big 'grind' as well, i dislike the cloud a lot, but if it means i get to play with stuff like Fusion 360 for nothing then i'll have to suck it up ;)


I'll try when i get back in later today
Dave
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on February 03, 2018, 09:32:22 AM
IIRC there used to be a way to keep your data local to your PC but it is been a long time since I looked.


Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 03, 2018, 10:34:25 AM
Here we go, should be .stl :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on February 04, 2018, 06:57:39 AM
here we go.
that is was Estlcam did, in two different strategy's.

Thomas
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 10, 2018, 08:38:26 AM
Very educational day :) Made my first assembly of parts designed and cam'ed by myself in Fusion and run on my Bridgeport CNC :)

Lots of errors of course, all spotted before running, mostly WCS choices but all easily corrected and parts made without a hint of damage to the old girl ;)

I can easily say that the powered knee axis taking tool length comp is brilliant, transforms the machine. Also the custom file load code works flawlessly in taking out the G43 lines.

An added bonus I discovered is that I do not need to call T100 when setting my height probe - any tool can be in the system and it still works! This seems to be because my knee routine reads the tool table directly for T100 length I think, whatever the reason, this is a major boost as forgetting to set the height for the probe was dangerous before :)

BUT (always a but) I'm getting the blasted ePid errors again, every single time i move an axis manually, any axis, while in the M6 loop - its the M6end code that triggers it, ANY code in M6end and it's ePid time :(

This is serious as it messes up the knee positioning routine a bit and also is just not right so needs fixing.

Now, I could put the TLC code back in the M6start BUT that can be dodgy as if going from long to short tools, the knee will come UP before you have a chance to pull the old tool out = crash possibility. As i have it now, the machine stops, you change tools and then the knee moves.

SO, i must fine a way to fix the ePid faults - any ideas guys??

I'm running Mach 062 BTW, very loathe of trying other versions as i cant risk upsetting rigid tapping etc which works ok.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on February 10, 2018, 11:10:05 AM
Hello,
had the same thing with this ePid fault.

i can see you are using CSLAB as well.

here the original answer from CSLAB as i went into this ePid Thing:

--- This fault can be activated by:
---  Bad Mach3 version. Bersions newer that 03.043.045 of Mach3 can cause ePID fault.
--- We recommend to use versions of Mach3 03.043.022 to 03.043.044. We always use 03.043.022 version as it's the most reliable in our opinion.


regards Tom

PS i "downgraded" to 03.043.022 and the ePid Thing is gone

i have written this a couple of sides earlier, i am running now without this epid Errors.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: metlcutr55 on February 10, 2018, 11:10:31 AM
great thread Dave, been following with interest.  my knee mill has a bad control which I hope to get going with either mach or uccnc this spring when the garage thaws out.  just a comment which I hope will be helpful.  mine is a 10 x 50 acra mill with square ways, and it rapids at 70 ipm.  when I bought it, it was at 100 ipm, but I had some control issues and slowing it helped.  thought yours was moving slower than this, just a little input to help.  fwiw, mine has a rolled ballscrew driving the knee, with a pulley and belt where the knee handle would go.  worked great.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 10, 2018, 11:16:16 AM
Hello,
had the same thing with this ePid fault.

i can see you are using CSLAB as well.

here the original answer from CSLAB as i went into this ePid Thing:

--- This fault can be activated by:
---  Bad Mach3 version. Bersions newer that 03.043.045 of Mach3 can cause ePID fault.
--- We recommend to use versions of Mach3 03.043.022 to 03.043.044. We always use 03.043.022 version as it's the most reliable in our opinion.


regards Tom

PS i "downgraded" to 03.043.022 and the ePid Thing is gone

i have written this a couple of sides earlier, i am running now without this epid Errors.

Thanks, does it work ok with CS's rigid tapping routine?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 10, 2018, 11:18:41 AM
great thread Dave, been following with interest.  my knee mill has a bad control which I hope to get going with either mach or uccnc this spring when the garage thaws out.  just a comment which I hope will be helpful.  mine is a 10 x 50 acra mill with square ways, and it rapids at 70 ipm.  when I bought it, it was at 100 ipm, but I had some control issues and slowing it helped.  thought yours was moving slower than this, just a little input to help.  fwiw, mine has a rolled ballscrew driving the knee, with a pulley and belt where the knee handle would go.  worked great.

Thanks, in this case its not speed related but a glitch in code somewhere that does not like manual movement while in the M6 loop, code moves are ok if called in a M6 macro.

I still have the old screw in my knee, seems ok for now.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on February 10, 2018, 11:27:05 AM
Thanks, does it work ok with CS's rigid tapping routine?

Never tryed:
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 10, 2018, 11:32:16 AM
Hmm.

There is another option just passed to me by a friend - have the machine make all the moves itself, ATC style, all i do is change the tool and press start.

I have most of the code in place for this, commented out, so i can try it easily.

One day it might get an ATC so could be well worth trying this.

The ePid only seems to come with manual moves so it may work.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on February 11, 2018, 06:16:55 AM
here:

https://www.machsupport.com/forum/index.php/topic,29032.0.html

is a thread about the same Situation.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 11, 2018, 07:39:46 AM
Thanks TPS, I think this just highlights some of the hidden things lurking behind Mach3 and external controllers / plugins - i guess once Mach development stalled, nothing could be done to fix them, and never will now.

I see the answer was to dump the xml and downgrade to 022 but that gave another issue with overrides it seems.


I tested the machine in pseudo-ATC mode today - let the machine make ALL the moves and i just change the tool - it works perfectly which is good and i can run with that now as its easier than reaching for the keyboard every tool change :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 11, 2018, 11:12:19 AM
Well, that was an educational, worthwhile couple of hours spent in Fusion....

I have some aluminium parts i make regularly, i do these on the high-speed setup using single-flute bits designed for aluminium. Run time is 26mins, paths created in Aspire.

I moved the part to Fusion, imported the DXF and run the CAM, same amount of tool changes, changed to 2-flute tools still recommended for aluminium. Run time 29:30.

Now, allowing for the massive drop in spindle speed from 24,000 to 4,000 I think that is very impressive, what helps is the two-flute tools plus the fact that due to the canted-out design of the high-speed head I have to baby the feed rates or it starts vibrating badly - no amount of fiddles seem to help this, you just have to go easy on it whereas with the main spindle I can whack the feeds up to proper limits - the tools are only 5mm and 2mm so she wouldn't even notice.

I need to do a test run to prove it but the other significant bonus is that i can use repeatable tooling instead of setting Z height 3 times for each part - this will likely save the lost 3 minutes :) :)

I was impressed anyway ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 12, 2018, 03:02:54 PM
Things are moving fast here :)

Now i need to engrave some aluminium parts, i'm thinking a drag-engraving tool for it?

Anyone know if you can output drag-engraving paths in Fusion?
They need the spindle off.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: olf20 on February 12, 2018, 08:32:40 PM
I've done a fair amount engraving. The results with
a v bit are always superior to anything I have found
so far.
Just my experience.
olf20 / Bob
Title: Re: Bridgeport Knee Mill Conversion?
Post by: RICH on February 12, 2018, 09:46:53 PM
I personally like to use a high speed rotary tool attached to the Z axis.
The Z axis should have no backlash and be very repeatable . Some work the cut depth is only a few thousands deep. I use several rotarys which run over the range of  18000 rpm to 65000 rpm. The higher ones are air driven.

Here is a link to some small engraving work done a long time ago.
http://www.machsupport.com/forum/index.php/topic,13398.msg87957.html#msg87957

This link shows soom engraving done on custom mirrors for a chopper.
http://www.machsupport.com/forum/index.php/topic,6187.msg40704.html#msg40704
http://www.machsupport.com/forum/index.php/topic,6189.msg40706.html#msg40706

I don't use V bits since they just don't hold up well in metal  and the cut becomes wide very quickly limiting
size of the engraving. Play around trying different ways to cut engraving.

All depends on what you want to so. A friend uses a spring assisted drag tool and does does nice work with it.

Don't know what Fusion has available these days. No need for anything fancy as you can use 2d pathing for flat work.

RICH
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 13, 2018, 02:21:35 AM
Thanks, i have Fusion sorted.

Its just a matter of finding a tool that will give quick and easy results on aluminium, I have a reasonably fast spindle at 24k but find the micro engraving bits far too delicate - this is what made me look towards drag engraving. They use drag on Zippo lighter cases, was on TV the other day and the result was perfect, of course they didn't say what tool ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: RICH on February 13, 2018, 11:58:43 AM
Maybe consider using a dental round bur. They come in different sizes and for fine engraving I use FG1/4 ( .5mm dia).
Do a search as you can find some paces that sell them in lots of ten @ around $1.50 each.

RICH
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 13, 2018, 01:51:40 PM
Thanks,

my main issue with rotary is that the material is not machined and there is no option to  machine a totally flat face on it, Its the side of some aluminium angle which usually appears concave slightly.

With the drag tools being spring loaded i would hope they work better?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: RICH on February 14, 2018, 07:42:46 AM
Dave,
The ball rotary burs I use have 6 cutting edges on the 0.019" diameter. They machine the material.
Drag seems to not work well  at very small size in terms of quality of the engraving.

Depends on what you want in the end and surely a spring loaded drag tool will do depending on the size and quality of the work to be done.

RICH  
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 14, 2018, 07:58:34 AM
Thanks Rich
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 15, 2018, 02:07:01 AM
Back to the main topic ;)

I have a possible option on a QC30 spindle for my mill, I have been weaned off the idea of TTS tooling by a friend so need to move to an ATC suitable spindle that has repeatable tooling - QC30/BT30

Can anyone verify this is a sane move :) IIRC the QC30 will accept BT30 holders without the locking ring (its missing anyway) ??

Also IIR you can pull the spindle on a BP out from the nose without touching the head??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 15, 2018, 04:22:35 AM
In reply to myself, yes you can pull the spindle easily but only if the screw holding the Z drive adaptor does not protrude into the spindle cavity in which case it blocks the top bearing and the Z drive will need to be stripped.

Question - can i re-use the bearings on my R8 spindle on the QC30 spindle??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on February 15, 2018, 05:47:49 AM
Only if you can remove them by pressing on the inner race. If you have to press on the outer race, the pressure will damage the bearings.


Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 15, 2018, 05:55:55 AM
I was advised if you heat them gently they should drop off.

Without stripping it, i don't know if the inner race is accessible due to the spindle nose.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on February 15, 2018, 04:40:57 PM
Theoretically if you can get the inner race to expand faster than the spindle then yes they should drop off.
I will take a look at my spares and see what I can see.


Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 16, 2018, 03:53:31 AM
Spindle is here :)

Looks good and apart from being a bit dusty the bearings might actually be worth refitting after a clean and lube, just to see if they will run, they feel ok.

So, with the QC30 nose, the locking collar is retained -can this be used to press off the bearings if heat fails??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on February 16, 2018, 06:46:48 AM
It looks like to press those bearings off you will have to push on the outer races and that will more than likely ruin the bearings. Remember that these will be running your tooling and we want to keep the tool within tenths and not holding up somebodies utility trailer.
Be very careful with the threaded part since it is cast iron and can be broken very easily, DON'T ask how I know.

Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 16, 2018, 06:49:09 AM
Thats a PITA, destructive removal :(

Will try some heat first, if not then its new bearing time if i can find a suitable part
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on February 16, 2018, 06:55:14 AM
The factory bearings are BIG $$$$$$$. I picked up some on eBay for a lot less. I believe that they are a 7207 AC bearing. Make note of how the old ones come off and reinstall the new ones the same way. Also look into getting some Kluber grease for the bearings. Very expensive but worth it in the long run. Someone may have an alternate suggestion instead of the kluber.


Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 16, 2018, 08:24:44 AM
Would this happen to be a suitable pair...

https://www.thebearingcompany.co.uk/product.php?id_product=7419

Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on February 16, 2018, 05:36:21 PM
They look OK and P4 should be OK. I would only buy spindle bearings from a know manufacturer, i.e. not Chinese "German" bearings.
If these are overseas no-name bearings I would be very weary. Also verify against the numbers on your bearings. If you can find the specs of your original bearings that will give you a target to shoot for.

Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: vista_joe on February 17, 2018, 01:27:29 AM
I just discovered your thread today so I joined the forum to give you a thumbs up.

WOW - you have really done a lot on your Bridgeport.  Great Job!

I have a BOSS 5, QC30, original steppers, geckodrives, vfd, 4th axis with servo...  I also realized very quickly the limitations due to the limited quill travel and am interested in adding a stepper or servo to the knee as you have done.  Can you share the list of parts you used?  I assume you also did the mounting bracket in Fusion360?  That would be great to see as well.

You indicated you want to add an ATC.  I'm anxious to see how you implement that with QC30 (if that is your plan). 

Joe
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 17, 2018, 03:13:55 AM
They look OK and P4 should be OK. I would only buy spindle bearings from a know manufacturer, i.e. not Chinese "German" bearings.
If these are overseas no-name bearings I would be very weary. Also verify against the numbers on your bearings. If you can find the specs of your original bearings that will give you a target to shoot for.

Mike

thanks, i'll verify the source.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 17, 2018, 03:18:51 AM
I just discovered your thread today so I joined the forum to give you a thumbs up.

WOW - you have really done a lot on your Bridgeport.  Great Job!

I have a BOSS 5, QC30, original steppers, geckodrives, vfd, 4th axis with servo...  I also realized very quickly the limitations due to the limited quill travel and am interested in adding a stepper or servo to the knee as you have done.  Can you share the list of parts you used?  I assume you also did the mounting bracket in Fusion360?  That would be great to see as well.

You indicated you want to add an ATC.  I'm anxious to see how you implement that with QC30 (if that is your plan). 

Joe

Sounds like yo have a nice machine there, i've spent way too much on mine but i cant fit a normal VMC in plus i like the big bed I have, VMC's always seem cramped ;)

I'll be using the QC30 spindle with BT30 holders and a drawbar, should fit as i have been told plus it makes ATC a lot easier.

I used a 700w AC servo on the knee, it takes a fair bit of torque (I measured 8-10Nm) to get it moving, plus it matches my other drives, Belt is HTD5x15 and i'm using the stock Bridgeport bevel gears and screw.

I'll find a pic of the bracket but it was very easy.
I'll be using the
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 17, 2018, 07:04:56 AM
I got the bearings off the spindle - this way....

Remove the locknut and washer, place splines in lathe chuck with packers to protect, get blow lamp, run lathe at low speed, aim heat at inner race-the spinning shaft ensures even heating. After a few minutes the bearing just slides off with a gentle start from a rubber hammer, rinse and repeat for each bearing but make sure to allow the shaft to fully cool between each cycle.

The bearings appear to be in good shape and i will refit them if only just to see if it works. I cleaned in a three-bath wash of white spirit going from dirty to clean then dried-off with paper towel and soaked in spindle oil (these will be going back with oil not grease), they feel slick and very smooth so i see no reason not to refit.

If it grinds itself to bits in a day then now i know how easy to change them it will only mean minimal down-time.

I have a feeling the hard part is going to be getting the spindle out of the quill - pretty certain I fitted a longer screw to hold the Z axis drive which will block removal of the spindle assembly. If that is the case it means stripping the Z drive down which is a bigger PITA.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on February 17, 2018, 02:03:38 PM
Nice to see that you were able to remove them without destruction. I will keep this method in the back of my mind the next time I have to do somethinglike this.

Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 17, 2018, 02:39:53 PM
I was surprised too, seems the critical temperature is 125c no more, i also blew air down the spindle to try keeping it cooler.

No damage, no sweat and all parts reusable.

To reassemble, I borrowed a baking tray from the cook room ;) wrapped the bearings in tinfoil, set my powder-coat oven to 120c, put a lump of 1/4" scrap steel on the tray, bearings on top and gave it 20 minutes.

I mounted the spindle vertically in the vise, gripping on the drive dogs, donned a pair of welding gloves and the bearings just fell on, no hint of pressure needed. I realigned the little "o" marks on the inner and outer races and also between top/bottom bearings, tightened the locking ring and left to cool, retightened and lock-tabbed it.

These were original bearings, specially ground and marked with codes, the tubes were measured and both were equal.

Spindle feels very smooth and is now wrapped in cling-film awaiting fitting.

I need to make a drawbar - one piece or two joined ?? Its a hell of a lot of turning if one piece ;)

Anyone know what thread is in a BT30 holder??
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on February 17, 2018, 08:46:54 PM
Have done bearings before it is sometimes amazing how much a bearing will expand (without damage) with some heat being applied. And just how strong a shrink fit can be.
IIRC "BT" holders are metric and CAT are imperial. The drawbar in my BTC-1 is two piece. If drawbar is being activated by an impact gun I am not sure you could get away with a two piece unit.

My son just made a drawbar for his M-head mill and he made it out of one piece. His is shorter than what you need. It fit on the Monarch CK-12 no problem.

Dave, you said you were not going to grease the bearings this time you were going to oil them IIRC. How are you going to supply them with oil on an ongoing basis??

Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 18, 2018, 03:13:24 AM
The head on my mill is the original style with oil cups - one for the bearings via a pipe cleaner drip-feed and the other was for the quill feed mechanism.

It's a total loss system - oil goes in, oil comes out but at least they get oil.

If i fit new bearings then they will likely be greased for life but you still need oil in there for the quill sleeve or it will seize - you cant mix oil and grease so just fitting greased bearings is not the end - you need to redirect the drip-feed to the quill sleeve or cap it off and use the down-feed oiler to lube the quill. To do this right needs a head strip IMHO.

I won't be using an impact wrench - this is BT30 tool-hoding so there is less need to rack the drawbar up mega-tight, when i get going on the power drawbar it will likely be a geared stepper motor system.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 20, 2018, 01:26:23 PM
A box full of very nice tool holders turned up yesterday, on special from my tool supplier :)

Also made the drawbar for the new spindle.

Now i just have to make a gap to pull the head apart....
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on February 20, 2018, 08:45:26 PM
Looking good.
Can't wait to see it in operation.

Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 23, 2018, 07:02:08 AM
QC30 spindle and BT30 drawbar fitted :)

Pretty easy task after all. Whether the bearings will hold up i don't know but they sound ok and did not get hot after 30mins of variable speed idling.

Of course, some idiot ordered the wrong tool holders and didn't notice, ER16 instead of ER20 :(
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Tweakie.CNC on February 23, 2018, 07:46:44 AM
Quote
Of course, some idiot ordered the wrong tool holders and didn't notice, ER16 instead of ER20

There is no answer to that Dave - just keep taking the medication (in my case Beer - and lots of it  ;D )

Tweakie.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 23, 2018, 07:50:55 AM
Turns out there was a reason for my insanity - the supplier does not do an ER20 :) Their range goes ER16-ER25-ER32 so i just ordered ER32 and the next one down :)

My stuff is ER20 & ER32

Easy fix is to order some ER25 chucks and ER16/ER25 collets - sorted.



If anyone is interested I will have a lot of nice R8 stuff for sale soon, will pop it in the forum section before it goes to the 'bay.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on February 25, 2018, 08:22:16 AM
Assessing spindle runout...

Yes we all know zero is nice but in the real world, on an old Bridgeport we also know that's not going to happen ;)

Measuring inside the QC30 spindle socket, I get these TIR figures...

Near mouth = <0.005mm
Half way up = <0.01mm
Near top = 0.01mm

Measuring an ER32 collet holder....

Near mouth = 0.04mm
Mid way = 0.01mm
Near top = <0.005mm

Seem ok??

This is not taking into account the collet/tool yet, this is with budget tooling.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on March 30, 2018, 12:05:40 PM
Still working on this :)

I have most of the parts for a power drawbar assembled now.

My idea is to let gravity do the down stroke - the theory is that it will make installing tools easier if the drawbar can lift a bit when the tool is loaded. If not then i can either use an air downstroke with air lift, or air downstroke with spring lift.

No ideas about control yet, I have various tiny PLC's on the shelf - would make it easy possibly to add the ATC later or i can add to my CSMIO setup. First off will just be a button or two and solenoid valves.

I'm using two valves - i want the wrench to drop first, then the power to be applied. The wrench can stay down until the next tool is fitted i think.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on March 31, 2018, 10:38:50 AM
Ok, so i finally got i all bolted up and the new drawbar made, mounted on the mill and, well clearly I still have work to do :(

The idea of allowing the wrench to fall will not work as the mechanism is not slack enough to let it - ok so we go to plan B and use air to push it - this works ok.

Next, the idea of not starting the impact until the Torx bits mate will not work - the Torx bits jam instead of mating about 75% of the time, might be able to improve this a bit by grinding the profiles a bit, will save that for later.

Next, with the wrench being held down, you cant easily insert a tool as it needs to push the drawbar upwards, but the cylinder is pressing it down so it risks cross-threading etc.

So I guess you MUST release the wrench after the tool is released? - I have no idea of the cycle here, all the videos just show it working, no real detail.

Does anyone know what i am missing here - anyone actually built a power drawbar for a threaded tool holding system like BT30??

Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on April 01, 2018, 08:20:45 AM
what would be to use a hex bolt insteed of torx,
in combination with a long nut it would allow the
screw to go into the nut without any pressure on
the screw.

just thinking.

Thomas
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on April 01, 2018, 08:31:06 AM
Thanks, I have made some progress now,

I had too much control of the wrench - removing the bottom bar has allowed it to move easily now.

The Torx has better torque rating than hex - I have modified the head a bit with the grinder and that has allowed it to mate easier now.

I am trying to find my PLC software disc so i can set up a simple control logic to get it cycling, its here somewhere.........
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on April 01, 2018, 08:40:34 AM
why using an external plc and not the cslab ?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on April 01, 2018, 08:49:38 AM
easier to mess about with until I know exactly what i want, thats all.

not good messing about in the cab i think, also easy to put it all to one side if i need to run the mill.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on April 01, 2018, 09:02:31 AM
i mean a outside hex screw with Long nut.
this would the screw allow to go up when you
insert new tool and you don't have to lift the wrench.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on April 01, 2018, 09:13:35 AM
Nice, thanks

I'll note that if we get to Mk2 ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on April 21, 2018, 09:13:45 AM
Ok so the project is still going on :)

I now have a custom screenset, probe, probing macro's etc all working well.

Today I was bothered by some odd vibration I had since fitting the BT30 spindle, here's a short video of the top...

https://youtu.be/MJAr941aL-U (https://youtu.be/MJAr941aL-U)

So I blamed the DIY drawbar, made another one, just as bad?

Tipped the head over and had a look and the splined portion of the spindle is clearly bent :(

https://youtu.be/jEhYINbUgzI (https://youtu.be/jEhYINbUgzI)

The tool section runs very true so not sure how you bugger a spindle like this??

It was like it when i got as i have had no crashes.

Now, not sure what to do really, it took ages to find that spindle, they are not that common. I have sold all my R8 tooling and only have BT30 now.

Can they be straightened?

I could push it out in the garden and torch it - it seems every time i get ahead she kicks me in the 'nads :(

Any ideas?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on April 21, 2018, 10:15:46 AM
Take you time and straighten it while you look for a better spindle.

Mike.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on April 21, 2018, 12:28:29 PM
Need to find an approved method first, I don't have much in the way of surface plates etc, do have a 20T press though.

Certainly a PITA though.

QC30 spindles are very rare and it cost a lot too.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on April 23, 2018, 02:45:15 PM
Total bend was 1.2mm so pretty bad.

Using my press and some patience, I now have it down to 0.04mm which i think is far enough.

Going to remove the back-gear as well as it gets hot at full speed and makes a racket too, not been used since going CNC anyway.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on April 24, 2018, 03:19:08 PM
All back together, runs smoother now and a bit quieter without the back-gear belt.

:)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on April 28, 2018, 11:24:32 AM
The tool path display - is there a reason the path is so small compared to my display???

(http://davekearley.co.uk/wp-content/uploads/2018/04/toolpath.jpg)

The material is only 5mm beyond the path shown.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 04, 2018, 02:56:35 AM
Ooh, thats a way back, pretty certain its in this thread though.

I have an encoder, a basic linear way(nylon block in channel) the encoder connects to a 2.5mm pitch belt in a loop, along the loop is connected an angle bracket facing an R8 socket.

The encoder is connected to an ENC module for the CSMIO, Mach3 has a macropump macro that looks at the input from this encoder and displays it on my screen-set, real-time. The screen has a "Zero" button and a "Set" button. The angle is lowered onto the socket on the setter, zero is pressed and the tool fitted, angle is lowered onto the tool tip and "Set" is pressed - this copies the encoder DRO to the tool table and then shows the table so you can give it a name etc.

Takes seconds to do, you can load tools in the middle of code if you forgot one or break one etc. The actual "height" displayed is irrelevant, its in an R8 socket which always locates on a set part of the taper just as the spindle does, the Haimer probe i use for TOM setting is also measured and entered - all my work is relative to this "tool".

The only cost was for the ENC module, the rest is all junk-box bits. It was a fun project basically, but quite useful.

Update -

Tool setter has now been shelved.

I have been chasing an odd error that manifests itself as cutters ploughing into my sub-table for no known reason by anywhere from 0.1mm to 0.5mm seemingly at random. After a LOT of testing and help from a friend, it boiled down to the fact that the tool setter i built was not accurate in all positions so the error varied with tool length.

It took many hours of testing with various styles of material top and tool length sensing but the results finally pointed to the setter outputting garbage and garbage in = garbage out as always. The most accurate method was to use the Z axis for tool measurement and tool table loading.

I have got some parts on way to mess about with but also ordered a bed-mounted tool setter that connects to my probe input so i can get back to automated TLO measurements - the price makes DIY pointless really but its from China so won't be here until next week. Supposed to have an accuracy of 0.001mm but i'll take that with a pinch of salt until i test it ;)

A lot of grief was given over this saga, my sub-table now needs resurfacing, the mill was pulled apart, code was checked :( and all attributed to lack of accuracy on the setter - the lesson learnt is that if you are telling a machine something is 50.023mm long then it better damn well be 50.023mm long ;) ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 04, 2018, 03:00:50 AM
The tool path display - is there a reason the path is so small compared to my display???

(http://davekearley.co.uk/wp-content/uploads/2018/04/toolpath.jpg)

The material is only 5mm beyond the path shown.

Yes - the reason is that the tool path display is designed to be square :)

Simple fix = zoom in before running.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 05, 2018, 09:27:29 AM
Impressed myself today.

While waiting for my tool setter to arrive, I built one from bits - 8mm ground shaft, linear bearing, scraps, odd switch from junk box.

(http://davekearley.co.uk/wp-content/uploads/2018/05/probe-done.jpg)

Ok, she's ugly - i wasted no effort on aesthetics, no aerospace grade aluminium was cut and its wired up with croc-clips :)

BUT...

This little bugger has an accuracy of 0.005mm - thats less than 2 tenths of a thou anywhere on the plate surface thanks to the linear support bearing :)

The switch is nothing special, a China import V3 micro with roller lever.

I'll probably end up using the bought one when it comes but shows what can be done with junk.

Hopefully get some time Monday to test it on real tooling and a small job.

:)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 10, 2018, 01:02:05 PM
Got the real height-setter mounted today.

All works nicely, my screen-set now sports a page for tool-setting with table/knee positions, speeds etc

Using CS-Labs M31 probing code.

Job done:)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on May 13, 2018, 09:05:18 AM
The new setter in action, simple and fast :)

Uses CS-Labs M31 coding.

https://youtu.be/YzV89lxtjcA
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 09, 2018, 07:02:34 AM
Mill strikes again :(


Ref all axes and the z fails with encoder too far from index pulse - it has done this before and it's an easy fix, just flip the belt round one step on the pulley and re-ref = all ok.

Went to set new tooling for a job, tell it to go to my tool setter position and find it's about 5mm out in X and 3mm in Y, Z is always Zero/home so that can't be out.

So, i re-homed and it did exactly the same thing, with no other option i reset the the setter ref positions and carried on.

Now, with a little red alarm going off in my head, I thought to check my master height probe position - easy to do as it is always tool 100 so i just set it as tool 99 so i can compare the two positions in the table.

Sure enough it was 3mm off!

So that is X/Y/C axes ALL lost or changed their home/ref position??

No switches have been moved so now i can't trust the machine again.


It's getting worrying now as i have started to use it more and more but yet again I find I can't trust or rely on her :( :(


Anyone have any ideas on what can cause this - don't forget this is a servo machine with CSMIO-IP/a controller and Mach3.

Thanks
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on June 09, 2018, 12:40:54 PM
ok you are doing a Referenz on index pulse.

means the ref Limit Switch is very secondary.

reference on index pulse means go t reference Switch reverse direction and look for the next Zero pulse of Encoder.

Quote
it has done this before and it's an easy fix, just flip the belt round one step on the pulley and re-ref = all ok.

this teels me that you have a seperate Encoder for Feedback Loop, witch is belt driven.

ok if you shift this belt for one step, it is "normal" that yor home pos shifts as well (index pulse !!)

Thomas
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 09, 2018, 01:21:04 PM
Sorry, not enough info

The error with the index was in the Z axis only

The positioning error was in XYC axes

Somehow something changed - i have my setter position stored in the screenset, it has worked well up to today when it was off by a few MM in three axes.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 10, 2018, 03:30:20 AM
Another issue,

I am trying to work a part that needs both sides machining, flipping on X axis, Y is against the fixed vise jaw.

Y alignment is perfect but X is shifted +0.5mm on the reverse side so the front and back have a step.

I have tried two probes for X ref - electronic and mechanical, same result so it's not the probe or any macro.

The code seems perfect - i simplified it to just two points, the front was perfect and the rear was shifted, the code is easy to read - front X40 rear X-40.

I was previously flipping Y axis and the fault moved to the Y plane instead.

It seems I cannot work one side in X+ and the reverse in X- or Y+ and Y-

Any ideas, this machine is doing my head in, its all pointing towards controller or Mach3 now.

I have one more test to run today but I'm not holding much hope.

All previous work was one sided so no issue.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 10, 2018, 05:52:41 AM
Finished my last test and it just muddies the water more:(


Made a part with two 20mm through bores at known XY offsets, I chose 35mm Y and 25mm X offset.


Without removing the part I then set my XY ref on the centre of the lower left bore and probed the upper right bore for its offset to verify the work,

The offset was verified on the DRO’s as 24.964mm X and 34.997mm Y, pretty accurate i thought


Next, I flipped the part as before, set my XY ref on one bore and probed the other, result was 24.970mm X and 34.984mm Y - still good.

I then set my XY ref on the other bore and probed the first one, result was 24.972mm X and 34.981mm Y - still good.

This tells me i should be able to machine two sides if i use a through-bore as a ref ?

But what i don’t understand is why i can't use the edge as ra ef when all logic says I should?

Probing the holes as above means the machine was in X+ and X- quadrants so is pretty realistic to the work.

I tried both mechanical and electronic probes and got results so similar that the difference is irrelevant to my work so will stick with my electronic probe.

Any thoughts?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on June 10, 2018, 12:05:08 PM
only possibilty witch is left, that your x- probe Routine is not ok, or?
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 10, 2018, 01:21:25 PM
I thought that too, but,,,

There is now a possibility that my head is off-tram despite my thinking otherwise.

I am going to go through it tomorrow and verify before any further testing as it would explain a lot.

Title: Re: Bridgeport Knee Mill Conversion?
Post by: TPS on June 11, 2018, 01:42:06 AM
you can also post your code, if you want.

sometimes 4 eyes see more than 2. ;)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 11, 2018, 02:15:08 AM
Thanks TPS but i proved the code was ok by just making a part with two points - one on each side.

That makes it simple to read and it still came out shifted on the mill.

Will know more once i have checked it over again.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 11, 2018, 01:28:15 PM
Well,,,,

If fixing what i found tonight does not do the job then i’m packing my bags and giving up!

I tested the head tram and it was out about as much as it could have been out!

Badly off in BOTH axes by a frighteningly big amount, more in the X but both very bad, I’ve never had the nod move before, usually just the rotation.

Whatever happened when that cutter loaded up was far more severe than i thought, odd that it failed to break but just have smacked the head a fair bit.

It's back on now and i have cut a customers one-sided job ok, I won’t know about the two-sided issue until Wednesday as jobs piled up again :)

I can’t believe that fixing this issue would not fix the job, fingers crossed.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Fledermaus on June 11, 2018, 04:47:46 PM
Dave

Are you tightening those tramming bolts to 50lbft? I used to find that the head was easily knocked out of tram when I just tightened the bolts to what felt reasonable. I was surprised when I used a torque wrench just how much tighter 50lbft was, and I always torque them now.

Allan
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 12, 2018, 02:07:58 AM
I never knew there was a torque figure!

I have a 10" spanner and just lean on that as hard as i can.

I do have a torque wrench so i'll check tonight.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 12, 2018, 02:08:23 PM
All at 50ftlbs now :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Fledermaus on June 13, 2018, 05:08:24 AM
Dave

The figure of 50 ftlb came from a BP series 1 manual that I found on line. It has proved good for me,.

Allan
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 13, 2018, 05:12:23 AM
Great, thanks.

There was only one that was below 50, all the rest were ok but good to know.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on June 13, 2018, 01:04:18 PM
Happy to say that fixing the head tram has fixed my problems :)
Title: Re: Bridgeport Knee Mill Conversion?
Post by: TOTALLYRC on June 13, 2018, 08:30:34 PM
SWEET!!!!
Mike
Title: Re: Bridgeport Knee Mill Conversion?
Post by: vista_joe on July 10, 2018, 04:03:14 PM
:D ;D :D ;D

This code version works perfectly, it's one impressive addition to the mill, just increased it's usability 200% I think, she's now got 350mm of Z clearance under code control  8)

Of course, with every new feature there are new ways to mess things up of course -
do not enter a new tool manually in the "Current tool" DRO,
do not jog the knee manually once you have ref'd the Z axis and set the first tool or probe,
always enter the 1st tool/probe manually in the current tool DRO
probably a million other ways to make balls-up :)

I think a good addition will be to add some code to check that the new knee position is still a negative number as the axis runs out of travel at zero :)

One thing that did fail is the Index Homing on the knee - keeps throwing "Index not within allowed distance" error which means the index pulse is out of range, will have read the manual on this one.


Code: [Select]
Sub Main()

If GetSelectedTool() = GetCurrentTool() Then Exit Sub ‘***Do nothing if current tool is called again

If GetOEMLED(1866) Then Exit Sub ***Ignore M6 calls LED

‘***Get the current G90/G91 state
CurrentAbsInc = GetOemLED(48)

‘***Get Axis Scale factors in use
XScale = GetOEMDRO(59)
YScale = GetOEMDRO(60)
ZScale = GetOEMDRO(61)
CScale = GetOEMDRO(64)

‘***Set All Axis Scales to 1
Call SetOEMDRO(59,1)
Call SetOEMDRO(60,1)
Call SetOEMDRO(61,1)
Call SetOEMDRO(64,1)
Sleep(250)

‘***Get old tool length
OldToolLength = roun(GetToolParam(GetCurrentTool, 2))

‘***Set the requested tool to be the current tool
SetCurrentTool(GetSelectedTool())

‘***Get new tool length
NewToolLength = roun(GetToolParam(GetCurrentTool, 2))

‘***Switch to absolute distance mode
Code "G90"

‘***Move Z axis to machine zero - fully retracted for tool change
Code "G53 G0 Z0”
While IsMoving()
  Sleep(100)
Wend

'========================================================================================
' Start of Knee Positioning Code
'========================================================================================
‘***Get the knee position in machine coordinates
CurrentKneePosition = roun(GetOEMDRO(88))

‘***Get the respective backlash clearance allowance for downwards knee moves
If GetOEMLED(801) Then ‘***On  = English Measure INCH
    ClearAllow = 0.125 
Else                   ‘***Off = Metric Measure MM
    ClearAllow = 3.0   
End If

‘***Calculate the knee machine move value based on tool length difference
If OldToolLength > NewToolLength then ‘***We need to RAISE the knee
    Code “G53 G0 C” & (CurrentKneePosition - (OldToolLength - NewToolLength)) + ClearAllow
    While IsMoving ()
      Sleep(100)
    Wend
    Code “G53 G1 C” & (CurrentKneePosition - (OldToolLength - NewToolLength)) & “ F100”
    While IsMoving ()
      Sleep(100)
    Wend
End If

‘***If the knee is currently higher than it needs to be, we first
‘***move it down, to ensure the final move is always UP.  This ensures
‘***backlash is taken out and provides more consistent positioning.

If OldToolLength < NewToolLength then ‘***We need to LOWER the knee
    Code “G53 G0 C” & (CurrentKneePosition + (NewToolLength - OldToolLength)) + ClearAllow
    While IsMoving ()
      Sleep(100)
    Wend
    Code “G53 G1 C” & (CurrentKneePosition + (NewToolLength - OldToolLength)) & “ F100”
    While IsMoving ()
      Sleep(100)
    Wend
End If

If OldToolLength = NewToolLength then
    ‘Message “Knee Will Not Move” ‘***Use this line for debugging
End If

'========================================================================================
' End of Knee Positioning Code
'========================================================================================

‘***If G91 was in effect before then return to it
If CurrentAbsInc = 0 Then
  Code "G91"
End If

‘***Put previous Axis Scale factors back
Call SetOEMDRO(59,XScale)
Call SetOEMDRO(60,YScale)
Call SetOEMDRO(61,ZScale)
Call SetOEMDRO(64,CScale)
Sleep(250)

End Sub
   

I know you are no longer using this code but I think the reason you had issues with the Index Homing was a typo in your code.
The line Code "G53 G0 Z0”  contains an incorrect closing double quote.
I ran across this while studying how you are implementing the knee movement.

Great work!!
I should get around to implementing this on my mill later this year.
Title: Re: Bridgeport Knee Mill Conversion?
Post by: Davek0974 on July 10, 2018, 04:15:50 PM
Yeah i got stuck several times with characters that look right but are not, since changing to Notepad++ its much better though :)

The knee axis is brilliant :)