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Mach Discussion => General Mach Discussion => Topic started by: Katoh on November 07, 2008, 08:40:04 AM

Title: Spindle Speed Troubles
Post by: Katoh on November 07, 2008, 08:40:04 AM
Hi to All
Ive recently connected a Digispeed DC06 to my router to control a high speed spindle motor.
NO Problems through Mach I can get Start Stop Forward Reverse and spindle speed (big Grin)
The problem arises when I move an axis being Either X, Y, Z the spindle will accelerate with the movement of the axis.
Ive checked the incoming voltage under movement doesn't change. The digispeed uses power from the VFD to use as its 0-10v logic well that doesn't change under movement either. I'm sure I have got the Digispeed configured correctly, according to the manual it does what it should. I thought I may have a floating voltage somewere between the VFD and the control box, I even connected the VFD neutrals to the main neutrals to no success. Ive been told it may be noise? All my cables are shielded and earthed, I don't seem to have a problem with anything else. My assumption is somewere in Mach when an axis is moved its also sending extra signals to the digispeed. Remember with no axis movement but the machine powered up it works like a dream.
Please any suggestions, Ideas I'm running out.
HELP
Title: Re: Spindle Speed Troubles
Post by: Chip on November 07, 2008, 01:09:43 PM
Hi, Katoh

This may be causing your Problem.

Check for a stable (locked in)  Pulse Frequency on the Diagnostic Page, It should show a value corresponding to your set hernial speed (25k, 25***, 45k, 44***),

If it's not stable your p-port output will vary during running of g-code and mouse movements, Causing your step-dir spindle output to vary your VFD output.

Look at the Optimization link for windows XP,  http://www.machsupport.com/downloads/XP_Optimization.txt

Do the item's one at a time, As you may not need all of them, May fix it.

Hope this Helps, Chip



Title: Re: Spindle Speed Troubles
Post by: Katoh on November 07, 2008, 07:39:42 PM
Hi Chip
I did a windows optimisation when I first loaded mach. I went through it again and I could not see anything wrong.
I don't really understand kernel speed, but I tried all the different speeds and they all do the same thing. With kernel speed are you after a speed that comes closest to matching what you set? Say if I set it to 35k then in diagnostics it comes in at 33k,
but if I set it to 60K and comes in diagnostics as 60.5k that would be a better option?
Anyhow that's not the problem.
one thing I noticed if I turn on the power to the spindle and the drives first then start the computer as it starts loading windows it will sent what seems to be a small pulse to the steppers and the spindle as the machine gets a little shutter and the spindle fires up for a fraction of a second. Or is this normal?
Title: Re: Spindle Speed Troubles
Post by: Hood on November 07, 2008, 08:01:46 PM
When windows is booting it often queries the parallel port and this can cause your motors to twitch.
That is why most breakouts have a Charge Pump function, they will not allow movement of the motors until Mach is in control of the port.
 There was someone with a similar issue a few days ago and they resolved it, I will see if I can find the thread and post a link if I can.
Hood
Title: Re: Spindle Speed Troubles
Post by: Hood on November 07, 2008, 08:03:51 PM
Heres the post I was thinking about, hopefully it will help you. http://www.machsupport.com/forum/index.php/topic,9377.msg57283.html#msg57283
Hood
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 07, 2008, 09:33:51 PM
hi Hood
Read the thread tried what they found out still no avail.
Funny thing that I just found out The spindle will only increase in speed when the axis movement is forward, backward movement will not increase spindle speed, well at least not noticeable.
Title: Re: Spindle Speed Troubles
Post by: jimpinder on November 08, 2008, 04:53:55 AM
You don't say whether this increase in speed is while the axis are moving, i.e. it slows again when the axis are stopped - or just carries on at the higher speed.

You don't say whether  you are using LPT1 port or Smooth Stepper, or what.

I was wondering if there is some fault in your port output which is causing some "cross signalling". Try altering the pin number that the PWM speed signal to the Digispeed goes out on and see if the problem persists.

Pins 2 - 9 are one address on the port, pins 1,14, 16 and 17 are a seperate address. The "dir" output on your spindle drive (bottom of Ports and Pins/Motor Putputs) should be configured port 0, pin0 since it is not used.
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 08, 2008, 07:16:03 AM
Hello Jimpinder
The spindle will increase speed while the axis is moving, once the axis has stopped the spindle will then go back to its set speed setting.
The digispeed is wired from BOB NO2 I have two BOB's on the machine. I don't have problems with Bob 2 as it running other functions and also an axis that are running fine.
The way I have configured the DCO6 is as follows
In the Ports and pins.
Spindle Step pin 16 active low, Dir pin 1 active low both Port 2.
In the outputs Output 1 Pin 17 active low port 2
This was advised for me straight from Peter Homann the maker of the Digispeed.
While the machine is at rest You can give it the command say "S7350 M3" and the spindle will turn CW at 7350rpm which is have its Max Speed the digispeed will have an output value of 5v, Give it the command "M4" and the spindle will stop and turn CCW at 7350 rpm Increase speed via Mach and it will increase all the way to 14700rpm digispeed will have an output value of 10v. No problem there.
Lets say spindle speed set at 7000rpm jog the machine forward either X, Y, or Z and the spindle increases speed. Jog the machine Backward and the spindle stays at a constant, (or I cant notice a difference if there is One)
I have taken the the power supply for the digispeed of a 5v terminal on BOB2, I have tried taking the power from BOB1 still no difference.
The BOB's are CNC4PC c10
Title: Re: Spindle Speed Troubles
Post by: jimpinder on November 09, 2008, 05:02:08 AM
I have no experience of the cnc4pc c10 boards, so I can only say we have heard of problems with them on the forum before.

I have a feeling that the common wires are something to do with the problem, and I think they reverse some of the input/output functions - i.e. a +5v input gives a 0v output from the board.

You do not need a Bob board attached to the Digispeed, your computer is powerful enough to drive it directly - mine does - so try running a single wire from the pin to your digispeed and cutting out the electronics on the Bob. You should be able to access the input side of the LPT1 wire on your Bob. See if this gives the correct performance. If it does, then this shows where the fault is.

You really need to trace the PWM signal from the computer to the Digispeed with an oscilloscope to see how it is corrupted. That is difficult if you don't have an oscilloscope - I don't either.
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 09, 2008, 06:17:51 AM
Hi Again jimpinder
I had a good chance this afternoon to do some other tests and try different things. Firstly I took all the power and neutrals to the digispeed from a separate power source, no good. I am in the unique position as well were I am running two BOBs of Se perate Ports. I swapped the digispeed to the other port still to no success. I tried using different pin no.s to no avail.
I think there is something more menacing than a small glitch were I disabled the the spindle in the ports and pins motor outputs config. and the spindle still fires up with the same problem. I am really starting to lean to that the Digispeed board itself is faulty or has some glitch in it. Not sure to replace it with a C6 speed control from CNC4PC or try another Digispeed.
I can get hold of an Oscilloscope (I think if its still there)but I wouldn't have clue how to use it or what I'm looking at.
Title: Re: Spindle Speed Troubles
Post by: Peter Homann on November 09, 2008, 10:34:48 PM
Hi Again jimpinder
I had a good chance this afternoon to do some other tests and try different things. Firstly I took all the power and neutrals to the digispeed from a separate power source, no good. I am in the unique position as well were I am running two BOBs of Se perate Ports. I swapped the digispeed to the other port still to no success. I tried using different pin no.s to no avail.
I think there is something more menacing than a small glitch were I disabled the the spindle in the ports and pins motor outputs config. and the spindle still fires up with the same problem. I am really starting to lean to that the Digispeed board itself is faulty or has some glitch in it. Not sure to replace it with a C6 speed control from CNC4PC or try another Digispeed.
I can get hold of an Oscilloscope (I think if its still there)but I wouldn't have clue how to use it or what I'm looking at.

Hi,

If you can use an oscilloscope, connect it to the step input on the DC-06. Enable the spindle and set a spindle speed so you get a constant smooth step frequency.( At some frequencies the step pulse jitters about a small amount as Mach cannot produce a pulse stream at all frequencies, so adds in extra pulses where needed.)

Then while monitoring the scope, move an axis and see if the step pulse stream changes frequency.

Do the above test with the spindle drive powered up and with it turned off. Let us know what you find.


Cheers,

Peter.




Then

Title: Re: Spindle Speed Troubles
Post by: Katoh on November 10, 2008, 12:07:17 AM
Hi Peter
After a lot of searching and reading through different forums, I came across something interesting not directly related to my components but put me on the right track. Firstly I hound with the C10 CNC4Pc BOB pins 1 14 16 17 only will give you an off/on control they dint have full motor functions. I tried pin 8 off BOB1 for the step comment to the digispeed and "SUCCESS the spindle speed will not fluctuate with axis movement. Now I'm left with the tuning of the motor in regards to the 0-10v output from the digispeed. I have set the motor tuning to 1000steps and velocity to 1450 which is nearly max.
I used 1450 as my spindle has a max speed of 14500rpm. In pulley setup i used pulley one min speed 0 max 1450 ratio 10.
The only trouble I have now is when you set the speed at max 1450 you get 10v, but when you set the speed at 725 1/2 speed you get 9v to confuse me further set the speed at 145 1/10 and I get  1v. can anyone tell me if and what Ive done wrong.
I also asked a question Earlier about Kerniel speed and what that should be set at? Or how do determine whats the correct correct speed 25kHz 35kHz 60 KHz ect.
Title: Re: Spindle Speed Troubles
Post by: jimpinder on November 10, 2008, 04:43:18 AM
I thought the CNC boards might be the problem - glad to see you have it fixed. I was on a bit of a wrong track, becasue I was thinking you were using PWM control, not step and direction - but we didn't get that far anyway.

Do not worry yourself about the "kernel speed" This is the base speed the computer runs Mach at. Mach works perfectly at 25 kHz. If your computer is capable then you can run it faster, I run at 35 kHz (I must admit, I have not seen much difference between 25 and 35).

As far as motor tuning is concerned with spindle speed, then  if you read the Mach instructions, there is a full explanation, and Mach can set your speeds automatically, if you have some form of tachometer fitted. This is a simple signal from the spindle to the computer once per rev. and from that Mach3 computes the speed.

You may need different speeds for different jobs - e.g I turn steel - 6.5 inch diameter wheels - a "slow" job. I also, on the same machine turn brass - a "high speed" job, and my machine also has a milling head so I look to 4000 rpm and maybe above for that,
The trouble is my electric motor - which is 3 phase, will only turn to a certain maximum. On the other hand, if I slow it down too much say below 50% of it's maximum, I loose torque (power) and cannot cut properly. You must, therefore make use of a gearbox or pulleys to control the spindle at speeds at which the motor is comfortable.

The speed  of each motor/pulley combination is known (certainly the maximum speed) and Mach 3 can set the output from the computer to give the required speed. It will also tell you if you are trying to go too fast (or too slow) on a certain pulley set.

Start with Pulley 1 (See Config/Pulleys) and set the speed from 0 to your maximum. Select Pulley one on the settings page. You should find that (even without a tachometer) that Mach3 has a reasonable stab at setting the right speed. If you fit a Tachometer, Mach can keep to within 2 or 3 rpm of the selected speed.





Title: Re: Spindle Speed Troubles
Post by: Katoh on November 10, 2008, 08:01:52 AM
Hi Jimpinder
Many thanks to yourself , Hood and Chip for the replies and suggestions.
The spindle is running as Sweet as Sweet can be.
Just so I ramble on a bit I should start another thread but Ill keep going with this one.
To those who are interested My Machine is.
3200mm long x 1800mm wide by 1200mm high moving gantry router.
Its X axis has a cut of 2700mm Y, 1250mm and Z, 260mm
It is run by 5x 900z/In steppers run by G201 Geckos and fed with 40amps of 48VDC.
Its constructed of Steel framing with Aluminum Gantry and aluminum parts machined on a Friends CNC also running Mach.
The spindle is a Fimec 3.5Kw (5hp) 380volt direct drive controlled with an AcTech VFD.
The machine is very happy running at 3000mm/min (118"/min) and is capeable of 6000mm/min(236"/min) without loosing steps.
the X axis is driven by Duel Rack and Pinion, the Y and Z 3/4" ball screws.
All three Axis are guided by Igus Drylin-W linear glides. (100%dust resistant and extremely accurate.)
Its Taken me just over one year to build and still not complete as I have plans for a 4th axis and Vac Table.
The Machine weighs approx. 1100Kg (2420Lb)
Ill postsome photos at completion. If any one wants more info about it please just ask me Ill be more than happy to share what I have done and learnt.
Title: Re: Spindle Speed Troubles
Post by: Hood on November 10, 2008, 08:12:53 AM
Sounds like a nice router, looking forward to the pics and you dont have to wait until its finished, its often nice to see machines as they progress :)
Hood
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 10, 2008, 08:32:52 AM
Thanks Hood
Ok Ill Take some pics and post them tomorrow night. If I can work out how to get the pics on the forum.
Title: Re: Spindle Speed Troubles
Post by: Hood on November 10, 2008, 08:37:40 AM
On the reply page you will see an additional options tab (lower left) you can use that to browse your drive for the images.
Hood
Title: Re: Spindle Speed Troubles
Post by: HimyKabibble on November 10, 2008, 11:45:57 AM
Hi Peter
After a lot of searching and reading through different forums, I came across something interesting not directly related to my components but put me on the right track. Firstly I hound with the C10 CNC4Pc BOB pins 1 14 16 17 only will give you an off/on control they dint have full motor functions. I tried pin 8 off BOB1 for the step comment to the digispeed and "SUCCESS the spindle speed will not fluctuate with axis movement. Now I'm left with the tuning of the motor in regards to the 0-10v output from the digispeed. I have set the motor tuning to 1000steps and velocity to 1450 which is nearly max.
I used 1450 as my spindle has a max speed of 14500rpm. In pulley setup i used pulley one min speed 0 max 1450 ratio 10.
The only trouble I have now is when you set the speed at max 1450 you get 10v, but when you set the speed at 725 1/2 speed you get 9v to confuse me further set the speed at 145 1/10 and I get 1v. can anyone tell me if and what Ive done wrong.
I also asked a question Earlier about Kerniel speed and what that should be set at? Or how do determine whats the correct correct speed 25kHz 35kHz 60 KHz ect.

I spent a lot of time setting up my spindle with a C10, and found the setting rather "fiddly".  Pulsewidth setting will significantly affect the response, as will steps/unit, and you have to play with both to get the response you're after, and to get the "S" values scaled as you desire.  In my case, I wanted the "S" values to range from 0 to 900, corresponding to 0Hz to 90Hz on my VFD.  I did eventually get there, albeit with some non-linearty.  But, on the days it beahves well, the error is less than 10%, and that is mostly at the very low end, where it's really not critical.  In the more usual operating range (40-90 Hz), the error is typically only a few percent.  Sounds to me like you may be getting a fairly linear response except at the top end, which suggests you're reaching 10V output well before an S value of 1450.  You can re-scale that response by reducing the steps/unit, so the output reaches 10V at an S value just short of 1450.  You'll have to determine the correct value mostly by trial and error.

Regards,
Ray L.
Title: Re: Spindle Speed Troubles
Post by: Peter Homann on November 10, 2008, 08:14:36 PM

Pulsewidth setting will significantly affect the response, as will steps/unit, and you have to play with both to get the response you're after, and to get the "S" values scaled as you desire.

Regards,
Ray L.

Hi Ray,

When I way developing the DigiSpeed DC-06,  I designed in circuitry that eliminates the step pulse from affecting the output voltage. The charge pump of the 2907 reacts to the energy in the step pulse, so if the step pulse is fed directly into the chip and the pulse width varies, then so will output. To eliminate this the DC-06 feeds the 2907 with a constant step pulse width regardless of the pulse width sent from Mach3.

When setting the max velocity of the Spindle axis in setup tab, a common problem that many do is provide too many steps, resulting in the maximum output voltage being reached before the maximum RPM setting in Mach is reached. This is then seen as a non-linear response in the actual vs desired speed.

The way to tue a DC-06 correctly is to do the following;

1. Determine the maximum speed of your spindle, for this example assume 10,000rpm.
2. Set your Max pulley speed in Mach to 10,000
3. Set the steps/unit  to 1000 in the spindle axis of the motor tuning tab and set the velocity to its max value allowed
4. run the spindle with the desired rpm set to 10,000. This will run the motor as fast as possible.
5. Adjust the output voltage attenuation potentiometer so that the output voltage is set to the maximum recommended for the VFD or motor controller.
6. leaving the desired speed set to 10,000 go into the motor axis tuning tab and start reducing the max velocity until the motor rpms start to drop.(you will need to in and out of the motor tuning tab to do this.

The point at which the rpms just starts to drop is where the output control voltage is just managing to reach the 10V required to drive the motor at max speed. With this setup you should get a reasonably linear relationship between the desired and actual speed.

Also note that these speed controllers are basically open loop and can be affected by external factors. For example a cold motor/drive-train may have more drag on the system than one that is warmed up, and therefore the speed my read slightly less until it has been running for a while.

I hope this helps,

Cheers,

Peter.

Title: Re: Spindle Speed Troubles
Post by: Katoh on November 11, 2008, 03:26:49 AM
G'Day Ray
Just as Peter describes setting up the spindle speed is spot on. Jimpinder sets it Exactly the same.
what I did I set The the steps in the motor tuning tab (spindle) to 1000 and then used Max velocity The step size I left at 2us and Dir at 2us which is recommended to run your Geckos. I found if you change it in one area Say spindle it will change them in all of them Xaxis, Yaxis Etc. So I left them at 2 for each Step and Direction.
Next Go to pulleys set it at your max speed ( I Dint Know your Set Up So Ill Speak For Mine Only) in my case 14700 min 0 the ratio 1.
Through mach I set spindle speed max (MDI Area) type s14700 <enter> then type M3 spindle enabled speed at max. I went to the Digispeed and measured the voltage coming out, I adjusted the "adjuster Have a mind blank cant think of The name of it" on the digispeed itself to give me 10v. Then went back to mach and set speed at S7350 exactly 1/2 went back and measured the voltage it was around 9v. Then went to motor tuning  Spindle and decreased the Velocity only. 1st try was around1/2 velocity  went back and checked what the voltage was it was about 4.6 set at 7350 via mach. getting close.
Do you get the drift just kept going back and forth only changing the velocity setting in the motor tuning till I got 5v at 1/2 speed 7350 and 10v at max speed 14700. then did a check went from 1470 speed gave me 1v, 2940 speed gave me 2v and so on till I got to max speed.
Took me about 6 goes but all I changed was velocity in motor tuning spindle that's all. (in my case for a router spindle speed +/- 10% is nothing but I got it down to nearly exact.
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 11, 2008, 06:15:02 AM
Hi All
Ive taken the photos of the machine but cant seem to post them. Ever time I go to -post them the forum comes back with sorry that topic used or something?. I cant get the Pics on.
Title: Re: Spindle Speed Troubles
Post by: Hood on November 11, 2008, 06:46:38 AM
Sounds like you need to rename them as there has already been a pic posted with the same name.
Hood
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 11, 2008, 07:03:55 AM
Ok Pic F1k front view, R1k rear view, G1k Gantry, Cbk Control Box note the bottle is not part of the CNC but used by the operating parrameter.
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 11, 2008, 07:06:25 AM
Just a couple of more pics
Title: Re: Spindle Speed Troubles
Post by: Hood on November 11, 2008, 07:29:02 AM
Looks an impressive machine and very nicely put together, great to see neat wiring  it shows a lot of thought has gone into it :)
You better watch you dont get too close to the dust extraction ;D

Hood
Title: Re: Spindle Speed Troubles
Post by: HimyKabibble on November 11, 2008, 10:10:40 AM
G'Day Ray
Just as Peter describes setting up the spindle speed is spot on. Jimpinder sets it Exactly the same.
what I did I set The the steps in the motor tuning tab (spindle) to 1000 and then used Max velocity The step size I left at 2us and Dir at 2us which is recommended to run your Geckos. I found if you change it in one area Say spindle it will change them in all of them Xaxis, Yaxis Etc. So I left them at 2 for each Step and Direction.
Next Go to pulleys set it at your max speed ( I Dint Know your Set Up So Ill Speak For Mine Only) in my case 14700 min 0 the ratio 1.
Through mach I set spindle speed max (MDI Area) type s14700 <enter> then type M3 spindle enabled speed at max. I went to the Digispeed and measured the voltage coming out, I adjusted the "adjuster Have a mind blank cant think of The name of it" on the digispeed itself to give me 10v. Then went back to mach and set speed at S7350 exactly 1/2 went back and measured the voltage it was around 9v. Then went to motor tuning Spindle and decreased the Velocity only. 1st try was around1/2 velocity went back and checked what the voltage was it was about 4.6 set at 7350 via mach. getting close.
Do you get the drift just kept going back and forth only changing the velocity setting in the motor tuning till I got 5v at 1/2 speed 7350 and 10v at max speed 14700. then did a check went from 1470 speed gave me 1v, 2940 speed gave me 2v and so on till I got to max speed.
Took me about 6 goes but all I changed was velocity in motor tuning spindle that's all. (in my case for a router spindle speed +/- 10% is nothing but I got it down to nearly exact.


That's pretty much what I went through on mine.  The only added confusion was I have a SmoothStepper.  It first took a while to realize the step pulsewidth timing in Mach3 had no effect, and then a bit to find a good pulsewidth setting in SS config.  The tuning can actually be done with either the pulsewidth or the steps/unit, since both have a similar effect (the C11 is basically integrating the pulses, so either more pulses, or wider pulses will have the same effect).  Once I got the pulsewidth into a reasonable range, and understood how the C11 and the SS worked, it was not terribly difficult to get the result I wanted.  The only problem now is some days it does not work correctly on power-up, and seems to need some time to settle down and start operation correctly.  That I still need to sort out.

Regards,
Ray L.
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 11, 2008, 05:03:31 PM
Hi Ray
Just one thing I have noticed with mach, I have also found sometimes if you type in M3 or M4 Or M5 it wont recognise it and comes back with an error. All I do is shut down Mach and restart it and it works fine, Don't Know why. I Haven't tried it yet but I'm going to see if theres a difference in starting Mach First and then powering up the CNC or doing it Vice Verse. Could Be interesting to see.
Title: Re: Spindle Speed Troubles
Post by: HimyKabibble on November 11, 2008, 06:04:55 PM
Hi Ray
Just one thing I have noticed with mach, I have also found sometimes if you type in M3 or M4 Or M5 it wont recognise it and comes back with an error. All I do is shut down Mach and restart it and it works fine, Don't Know why. I Haven't tried it yet but I'm going to see if theres a difference in starting Mach First and then powering up the CNC or doing it Vice Verse. Could Be interesting to see.

I've seen more than my share of "quirks" in Mach, but that's a new one by me!

Regards,
Ray L.
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 11, 2008, 09:41:09 PM
G'Day Ray
I just tried a few things and found something interesting. If I switch the power off to the computer and then switch on (doesn't matter if the CNC is powered on or off, load mach, go to MDI screen and type s1000 it comes back with line 2 - unspecified error down the bottom will show syntax error, on the spindle speed it will put in 1000, if you click on spindle start the spindle will start. stop the spindle and type m3 nothing happens or type m4 still nothing. So what I have to do then is close mach shutdown windows and restart load mach and everthing is fine.
You could be experiencing the same problem without knowing it because it doesn't seem to do it all the time. were you load mach run your code and the spindle does stupid things. try before you run any code just starting and stopping the spindle using m3 or m4 command and see what happens. if you get the same thing it must be a computing/program problem.
As I said earlier it wont do it all the time, when I tested then it did it 4 times in a row before I got it to work properly.
Title: Re: Spindle Speed Troubles
Post by: HimyKabibble on November 11, 2008, 11:29:09 PM
That's completely different from the problem I've had.  M3/M4/M5 always work correctly.  The only problem is occasionally first thing in the AM the speed is off.  Just let it run, and it will settle down to the correct speed.  I'm pretty sure it's a analog flaky in the BOB.

Regards,
Ray L.
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 12, 2008, 12:56:05 AM
Ray
Just an obscure thought. are you using VFD? If so could it be that your Capacitors in the VFD are starting to get a bit dodgy.
Maybe they are not holding there charge or need a bit to get a charge into them. Have you checked first thing that your speed control unit is sending out the right voltage if so I would look at the VFD itself, and probably the first place would be the Cap's.
Title: Re: Spindle Speed Troubles
Post by: HimyKabibble on November 12, 2008, 10:46:45 AM
Ray
Just an obscure thought. are you using VFD? If so could it be that your Capacitors in the VFD are starting to get a bit dodgy.
Maybe they are not holding there charge or need a bit to get a charge into them. Have you checked first thing that your speed control unit is sending out the right voltage if so I would look at the VFD itself, and probably the first place would be the Cap's.

I am using a VFD, but it is less than a year old, and work perfectly from the front panel.  The control voltage coming out of the C11 is squirrelly on occasion.  On one occasion, an S command that should have yielded 1V out, instead gave 8V out.  Over a period of 5-10 minutes, it gradually worked it's way down to where it belonged, and worked perfectly the rest of the day.  It just seems to have morning sickness some days.

Regards,
Ray L.
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 12, 2008, 05:12:04 PM
Hi Ray
WOW that is a strange one, Ive got a bit of a mental block at the moment, but if I think of something through the day Ill jot it down and post it.
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 12, 2008, 08:18:49 PM
Ray
I thought of a couple of other things you may want to check. the 12v from your VFD to the board have you checked that the volts are right first thing at start up. Have you got that 12v isolated from the rest of the control power, especially the neutral? If all is good could You have a bit of moisture around the boards giving you a slight short then once things get a bit warm the moisture goes. or maybe you got a bit of dust, Ive seen a 240v power outlet Arc and short from dust settlement on it. Other than that I do not really Know, It must be what you were saying a problem in the board, could have a slight short and as heat increases so does resistance then works fine.
Title: Re: Spindle Speed Troubles
Post by: HimyKabibble on November 12, 2008, 09:10:02 PM
Ray
I thought of a couple of other things you may want to check. the 12v from your VFD to the board have you checked that the volts are right first thing at start up. Have you got that 12v isolated from the rest of the control power, especially the neutral? If all is good could You have a bit of moisture around the boards giving you a slight short then once things get a bit warm the moisture goes. or maybe you got a bit of dust, Ive seen a 240v power outlet Arc and short from dust settlement on it. Other than that I do not really Know, It must be what you were saying a problem in the board, could have a slight short and as heat increases so does resistance then works fine.

Supply voltage from the VFD is dead-stable.  Entire analog output circuit is totally opto-isolated from everthing else in the system.  It's down to either the SmoothStepper is outputting the wrong step frequency (which I doubt) or the analog output circuit (LM2907) on the BOB is misbehaving.  I just haven't had the opportunity to put the scope on it when it's acting up, to see exactly where the problem is.

Regards,
Ray L.
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 12, 2008, 10:38:14 PM
Hi Ray
Sounds like you got pretty much down to one of two things, I cant really help with either as I don't use C11 board or smoothstepper nor have had any experience with them.
Good luck with that!
I wonder if theres anyone else who has experienced or is experiencing the same problem with the Mach compands M3, M4, M5 as what I am.
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 12, 2008, 11:10:42 PM
Ray
Have you spoken to Arturo. from CNC4PC about this probleme. Id imagine he would have a better idea than anyone else, as the C11 board comes from him.
Title: Re: Spindle Speed Troubles
Post by: HimyKabibble on November 12, 2008, 11:58:22 PM
I've mentioned it to him, but not much he can do until I have more information about the nature of the failure. 

Regards,
Ray L.
Title: Re: Spindle Speed Troubles
Post by: Katoh on November 16, 2008, 12:49:04 AM
Hello to All
Just to finish off this Post, You would have read how we sorted the speed problem by using a different pin assignment, In the case now were mach was not recognising the M3 M4 M5 commands has been fixed as well, Many thanks to Hood for an interesting conversation this morning not all about CNC either. The Problem lies in the Version of Mach 2.63, So to anyone experiencing this trouble please download the latest mach version and install and your troubles will be gone. The only thing is Like me wright down all your settings in mach first so you can reconfigure the new Mach (eg config ports pins, Motor tuning, pulleys ect all Info you have put into config). Sometimes copying and pasting your XML files doesn't always work have a Backup saves a lot of trouble later.
All The Best
Katoh