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Messages - metlcutr55

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21
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« 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.

22
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« 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.........
 










23
General Mach Discussion / Re: running mill and lathe?
« on: October 02, 2015, 01:52:17 PM »
regarding the swapping of cables, although the situation is not exactly the same, i have a lathe and a mill that share rs232 communication with the same

computer, i ran the computer output into a cheap but industrial grade A-B switch, turn the switch to A, the mill is connected, to B and the lathe is connected.

maybe this is a possible solution.

24
General Mach Discussion / Re: Mach3 Major Bug?
« on: June 23, 2015, 11:46:10 AM »
another thread about mach leaving me pulling my hair.

im just a guy with an old dos based knee mill cnc and an old fanuc engine lathe.  both controls down, too old, dont want to fool with them,
i want to go to mach and an external motion control device and modern computer with modern software.  something i can put
together thus learning the internals so i (with help) can maintain my own stuff rather than calling the $$ fanuc man.

every time i think im ready to move a little, i get cold feet.  i sense that most of the many many problems seen on these forums
come from someone wanting to couple a laptop to a $10 chinese bob, and drive steppers stolen from god knows where and
wired improperly.  so i get inspired, until i see a post like TP's above.

other very knowledgeable folk on this forum have seemingly incorporated mach3 into machine tools and are very satisfied.

leaves me very confused.  what version of mach3 is the least buggy, and what are those bugs?  can i at least depend on
one version to act in a stable manner if i am willing to avoid certain programming techniques?  is mach4 really better?  reading
the mach4 forum section leaves me pulling my hair too.  is there any mach version buttoned down and ready to roll, if the machine
is properly built from good quality components?  TP said "the competition zoomed right by..", TP, do you mean that systems
like Eding, usbcnc, others may be better alternatives than mach?

are there any threads i have missed that serve as a faq for all the above questions?

i welcome all input, in this thread, on this forum, or via pm.
thank you,
ken


25
Show"N"Tell ( Your Machines) / Re: Nice Router Build
« on: July 20, 2013, 09:15:59 PM »
jmho, ymmv, but i cant help but think that that design would be many fold more rigid if:

the builder had used rectangular tubing on the base of the gantry sides that extended to the top and bolted to it all the way.  even if the rect tubing was open on the back face to clear the stepper.  a pair of triangular gussets on both sides of the machine added now running from the tops of the rect tubing to the tops of the endplates would be much more rigid.  i might even tie the 2 backsides of the triangle hypotenuses together with 2 straps ea for more rigidity. an "x" shape would be better.

a sawcut aluminum "x" connecting the 4 corner edges of the alum endplates would help too.  even a solid plate but that would be more cumbersome.  a pair (front and back) would help even more so.  maybe the back not needed since it looks like the spindle mount hangs on extruded shaped tubing. i might put a brace in the middle of the extruded tubing linking them, and check that the distance from guide tube to guide tube is the same in the middle as it is on the ends.

id bet the machine would hog faster, be more accurate in corners finishing, and run quieter and give better tool life.  again, jmho, ymmv.  im not a machine builder, but i did stay in a holiday inn express.....heh....on a more serious note, i have a cnc bridgeport in the garage, not so rigid, and run a large horizontal workcenter for my day job, very rigid, trust me rigid is good.  perhaps your demands dont justify this, just trying to help.

ken










26
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hi Hood!

i am still leaning towards that kit as is, for a couple reasons.  1st being my lack of electronics knowledge, thinking a very plain mach install is within my capabilities, messing with servo drives and controllers with multiple parameter inputs may be too much for me.  i am happy with the dc brush motors on my mill and hope the kit motors would be comparable in quality.  second being cost.  id try stepper but i am not liking the motor noise i hear on various vids.  i see the kit as the next step above steppers, if i can just get this lathe cutting again, i can modify the system to use a motion controller instead of the parallel port, and/or add better motors/drivers later, after ive made a lil $$.

what penalties will i pay going this way, simple brush servos, parallel port control, no external controller, "basic" mach3, vs doing it up as you have described?

i am waiting to hear from my electronics guy about getting the non x-z motion items on my lathe rolling less the fanuc.

i see little input here on this board about vendors and their level of kit support.  i see mostly negative input on cnczone about this question.  i welcome pm's from folk about this question, tho myself, i tend to air such maters publicly, a good job deserves a pat on the back, and vise versa!

thanks all for reading.

ken

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27
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hope my previous post was not too wordy as to put people off.  the more i think about this, i see it as 2 separate issues.  control of all the non x-z motion items, and control of the x & z with mach3.  i believe i will get my electronics-electric guy over here and see what we can do about getting the spindle to turn, and the brake, coolant & oiler to work without the fanuc stuff in place, and see what i will need to convert the power for all these items and get them properly switched.

once my lathe is working again but without x & z motion, i will attempt (with help if needed) the basic install of a kit and mach3.  if i can accomplish this, i will have functionality again, i can always control the spindle, coolant etc manually, and use mach cnc and jog to move the x & z.

3 issues i guess, i will want the stuff to all work together but i can attack these issues one at a time, likely 1st an index for threading, then the mpgs, etc etc.

i took a few pics inside the cabinet, ill post them in case anyone has comment.  ill try to make them thumbs but im not exactly sure how.  hoping to reuse a lot of this stuff.


from shop 003 by metlcutr55, on Flickr


from shop 004 by metlcutr55, on Flickr


from shop 005 by metlcutr55, on Flickr


from shop 006 by metlcutr55, on Flickr


from shop 007 by metlcutr55, on Flickr

once again, im really interesting in anything anyone has to say, about the kit ive "chosen", about vendors, etc etc


thanks
ken

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28
i have had issues with sticky, imprecise homing switches on my mill at times.  by clamping a tooling ball in my rear table t slot far to the x+ side as possible (this puts the ball in the general direction where my x-y home on my machine) and leaving it there, i can always go to the ball, indicate it, and set x-y zero.  then by using a tool holder with a flat ended rod i can go to x-y zero and set a z zero using a flat block or a shim top of the ball to the flat rod face.  it should be simple from there to find a pseudo xyz home for your machine near the limits of travel. if you set the tooling ball xyz zero each time you start up, travel to the pseudo home and re-zero, then when using your work offsets g54 thru g58 and g59 p1 thru g59 p253 as your work coordinates, you will always have a known reference point on your machine to re-check to, and your work coords should always be valid after using this "rube goldberg" homing scheme.  do learn to use your work and tool offsets, they are what make cnc machining a precise repeatable process with minimum headache.  hope this helps.

i have also considered adding a bored hole to my table to fit a tooling ball with a ground stem and flange, so the tooling ball can be inserted, picked up, then removed.  have not done it yet.

29
Show"N"Tell ( Your Machines) / long time gone, not forgotten
« on: April 01, 2013, 09:34:17 PM »
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long time since ive posted, doesnt mean ive given up.  been reading a lot, have learned a lot, but has also brought up more questions.  looking at Peter Homanns website, he has diagrams showing his breakout boards connected to both gecko stepper and servo drivers.  i have confidence after comparing these that the difference is not that great and i can handle a brush servo install as well as a stepper install and i think thats the way i want to go.  it doesnt appear that Peter's webstore is aimed at a servo kit as large as i will need for this lathe, so i have been looking at Automation Technologies, Motiontek, and CNC4PC for a kit.  i like the plug in approach used by CNC4PC as well as the drivers which seem to be the "CNC Drives from Hungary" that Hood has spoken of.  this kit has held my attention:
 http://www.cnc4pc.com/Store/osc/product_info.php?cPath=64_96&products_id=551,
 id request a 2 axis version.  Hood's comment of my old fanuc motors being about 1.9Nm continuous, these kit motors look about 85% of that, should be close enough.  im hoping to keep identical motors on the x and z, the x motor may be an issue because of space.  maybe a physically smaller motor, or perhaps have my buddy Perley the fab guy over with his tools of destruction for some sheet metal modification.

one of the places ive been reading a lot has been the mach1mach2cnc yahoo board.  lot of interesting topics there, lots of opinions, but has been a lil scary for me.  makes mach3 seem like it can sometimes be an unstable problematic control system.  i guess the discussion there centers around problems and solving them, likely the large majority of successful m3 installs are not discussed there, and i am just paranoid.  just need my lathe to do what it did before, turn, face, bore and thread.  chamfers and radii.

since i have confidence of my understanding of the lathe axis' cnc motion control, i think i want to shift my attention to controlling the other things the lathe must do:  i have a big cable full of 3 phase power coming into the main switch.  somehow all that juice makes the fanuc stuff run, makes the spindle go, the mechanical spindle brake work, the 2 speed spindle motor (this is not a servo motor) switch hi-low, run in 2 directions and stop, the oiler and coolant pump run.  once in jog mode, theres an x and a z mpg that work as crank handles, and are tempered by a feedrate selection switch.  and theres also a joystick thats tempered by the same switch and allowed me to move x or z  or x and z simultaneously.  those mpg handwheels also work independent or together, and having the joystick and the handwheels aid greatly in "manual" operation of the lathe, as does the coolant toggle switch and spindle ccw-off-cw lever, and the feedrate rotary.  i know these can be mach controlled, but if youve been a "manual" engine lathe guy, you prefer to keep them.

as i see it now i need to gain understanding of the stuff in the above paragraph.  ill think it has much to do with my lathe converting the 208 3 ph to smaller voltages and amperages and more, that will drive relays that will activate contactors (there are a whole lot of them in the old control cabinet) that will distribute all this power in graduated doses to proper destinations.

ive learned a lot about the stuff in paragraph 1 from reading and watching vids.  hardly anything about the stuff in paragraph 3.  as i said when i started, small steps.  no screwdrivers or soldering irons in my near future, can you folk point me to reading and vids that will help me understand the stuff in paragraph 3 and how it will interface with with the stuff in paragraph 1?  will the vendors in paragraph 1 be helpful with this?  there must be opinions of these vendors, if so id love to hear them, if posting to this forum is inappropriate, pm me and thanks!

regarding the mach1mach2cnc board, the questions that most come to mind are, just parallel port or smoothstepper/other pulse gen?  lot of questions about difficulty of interface and support documentation.  tough for a noob.  and i find myself wondering about the best build for the lathe that will work well in mach3 but be an easy conversion over to mach4.  it may take me a long while to get this done, thats ok not in a hurry.

the more you folk have to say about any of this the more i learn and the better i like it.  thanks!!







30
Ray and Paul, thanks for the info on steppers, exactly what i was looking for.  i am the noob here, a good machinist who has to (wants to also) retro his old fanuc control lathe to mach3, and knows not much about steppers.  thats the direction i was leaning, i am not so sure now, i am getting some input that servos are not that much harder to do, and the concern i still have about steppers is heat and noise.  perhaps these are also myths, i do not know.  i am guessing steppers for my lathe would have to be in the 1800 oz in range, servos perhaps a bit smaller.  i will disagree with Paul in 1 small aspect of vertical mill use.  90% of my work here at home takes place in a kurt vise, i bet steppers would drive my mill fine and be plenty quick enough (although it came with servos in the 1 hp range, i am not sure of this but its what others more savvy than i have told me)  the other 10% might be noticeably quicker with the servos, that work can often span the 33" x 16" xy range of the table and includes many holes and features.  my servo driven mill rapids at 120 or 150 ipm in xy, cant remember right now, and it accelerates very quickly.  the beast horizontal i run at my day job rapids 1700+ ipm, and the advantage over my home mill running at less than 10% of this is obvious on jobs with lots of rapid moves.

Leif, thank for letting me play in your thread, Ray and Paul thanks for the info.  Paul your point on engraving was a good one, tho it shouldnt affect my lathe much.  now off to research the myth? that a mach3 driven single pulse per spindle rev threading system may have its limitations and what they may be.

a very happy holidays to all !!

ken
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