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Author Topic: Progressive Move Error with X and Y  (Read 35621 times)

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Offline Sage

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Re: Progressive Move Error with X and Y
« Reply #90 on: August 28, 2008, 09:48:07 AM »
By the looks it you moved the Y-axis BOB hardware to a completley new set of parallel port pins and it works. So that most likely means the BOB hardware is fine for the Y-axis. That pretty much points to the parallel port being bad or possibly wiring on the BOB for those pins (4or5). Not sure what happens on the board.

Your next move to test the Z-axis completley baffles me. You've really confused the issue (for me). But there may be some useful information buried in there none the less.
From what I can see you have taken a good pin (2) which was working fine on the X-axis and used it along with a pin (4) that could have contributed to the Y-axis not working and discovered that it doesn't work for Z-axis either. You may be safe to assume that pin (4) s the culprit.
Do you see the common problem here? Remember I suggested to look for what's common when you try stuff?
 The only problem with your approach is you've introduced a different set of hardware i.e. the Z-axis to test the pins. That inroduces another possible unknown.
 Forget about the Z-axis for now. Use your good stuff (X-axis) to test the susicious stuff. When you finally find another set of good pins by testing them with known good hardware like the X-axis then use those new pins to drive Z-axis and leave the X and Y on whatever works for them (what you have already found that works).
  The approach now would be to continue proving that pin(4) in the problem. You should probably try it with know good hardware like making the X-Axis use it. Leave the Y-axis on the other known good pins.

Try this slight modification to what has proven to work.

X-Driver Step   -   4 (was pin 2 and was working fine)
X-Driver Dir                   -   3
Y-Driver Step   -   8
Y-Driver Dir                   -   9

In this example the X axis will probably screw up because pin 4 is being used to step it.
If that works for some strange reason try pin(4) as the X-Direction signal and put 2 back as the step. Direction doesn't do much but I suppose if it were picking up noise the driver might toggle back and forth a step or two instead of going in one direction.

Gong further, pin 5 was also a possible contributor to the Y-axis not working it should be tested in a like manner i.e move JUST pin (5) to a know good confirguation.

Baby steps targeting a particular signal is best to avoid confusion.

Sage


« Last Edit: August 28, 2008, 10:03:40 AM by Sage »
Re: Progressive Move Error with X and Y
« Reply #91 on: August 28, 2008, 10:03:59 AM »
Sage,
    That could be a bad recommendation, depending on which version of the CNC4PC BOB he has.  The earlier ones used *very* slow optos on some outputs (30-60 uSec rise times), so cannot be used for step signals at any reasonable step rate.  The board is marked as to which ouputs are appropriate for faster signals, like step, and which are not.  If he has the current rev of the board, this is not a problem, but with an old one, it definitely is.
    Also, your conclusion in the first paragraph that "the BOB hardware is fine" is a bit hasty,IMHO.  I was able to perform similar tests on my machine, and ruled out the BOB as a result.  In the end, the problems WERE caused by the BOB, which acted up mostly only when multiple axes were running.  It was a number of noise problems and design issues on the BOB itself.  Replacing the BOB has completely cured the problems.

Regards,
Ray L.
Regards,
Ray L.

Offline Sage

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Re: Progressive Move Error with X and Y
« Reply #92 on: August 28, 2008, 12:29:05 PM »
HimyKabibble:

You could be right. But the difference between you, cmnewcomer and me is is that you both have the hardware in front of you. I'm just trying to convey reasonable troubleshooting princples (which appeared to be lacking) so he can draw some reasonable conclusions as quickly as possible.  If you put the thing in front of me I'm sure I'd come to the right conclusion about what's going on pretty quickly. I've been doing electronic maintenence for 32 years.
  Following the principals I'm trying to convey and keeping accurate track of the results without confusing the issues, the conclusions would be the same anyway. If pin 4 is one of those that cannot handle the high speed it would be weeded out as not working for that function. Eventually you'd end up with a set of pins that work. (He's already 2/3 of the way there). Assuming of course the BOB has 3 pins (XYZ) that are up to the task. Maybe it doesn't. You can tell him that.

Sounds like you've had EXACTLY the same problems. If that's the case then scrap the BOB and get on with life. Life is short. Running the machine is more fun than troubleshooting any day. Spend the extra money and go with the PMDX 132 which can take 4 Gecko's. I've Had absolutley no issues with mine.

Feel free to take over and coach since you know about the inherent problems with the board. I wasn't aware that the BOB might be a piece of crap.

Sage

« Last Edit: August 28, 2008, 12:43:01 PM by Sage »
Re: Progressive Move Error with X and Y
« Reply #93 on: August 28, 2008, 08:56:43 PM »
Ray,

I'm using shielded cables for the steppers and my limit/home switches and I have a good case ground which uses equipment ground.  My CNC4PC board is the C11 Multifunction Board Rev 3.1.  Not sure if that's good or bad.

I justed completed testing and eliminated pins 4 and 5 on the breakout board.  So X used 2 and 3, Y used 8 and 9, and Z used 6 and 7 where even is step and odd is dir.  After 5 full runs of the program there was no error!!  So it appears that I either have a bad breakout board or a bad parallel cable.  It appears that when both pins 2/3 and and pins 4/5 are connected, there is some type of coupling or cross talk.

I tried to wire direct and am unable to get things to work.  I wired the pins from the parallel cable for step and dir directly to the Gecko driver.  I then tried to use the USB 5V for the common connection on the Gecko driver but no luck.  I even connecting to pin 18 on the parallel cable.  I certainly don't understand how the 5v reference is suppose to be wired in regard to the parallel pins. 

Sage, yes, my troubleshooting skills are lacking in regard to electronics.  Way over my head but I do thank you for the suggestions along with everyone else that has helped.  This has been an invaluable source for me.

Best Regards.

Carl

Offline RICH

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Re: Progressive Move Error with X and Y
« Reply #94 on: August 28, 2008, 11:50:47 PM »
Carl,
One thing at a time. One major component of the system at a time. Complete Sage's checkout of the BOB or better yet
just eliminate it from the system for the time being as suggested numerous times. Be simple, get one working good axis and build on what is working.
RICH


Offline Tweakie.CNC

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Re: Progressive Move Error with X and Y
« Reply #95 on: August 29, 2008, 02:49:35 AM »
A word of warning - when wiring direct and bypassing the BoB be aware of the fragility of the LPT port. It only takes a few mA in the wrong direction to destroy the port completely and possibly the mother board as well.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline Sage

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Re: Progressive Move Error with X and Y
« Reply #96 on: August 29, 2008, 08:54:08 AM »
Glad to hear it's working. Enjoy.

PS> Eliminating the BOB was only suggested as a trouble shooting step. As a general rule, be sure to use some sort of BOB. The Gecko's will be fine driven directly since they effectively have a BOB circuitry built in, but all kinds of disaster could happen if you wire external signals directly to the parallel port.

Sage
Re: Progressive Move Error with X and Y
« Reply #97 on: August 29, 2008, 09:57:59 AM »
Ray,

I'm using shielded cables for the steppers and my limit/home switches and I have a good case ground which uses equipment ground. My CNC4PC board is the C11 Multifunction Board Rev 3.1. Not sure if that's good or bad.

I justed completed testing and eliminated pins 4 and 5 on the breakout board. So X used 2 and 3, Y used 8 and 9, and Z used 6 and 7 where even is step and odd is dir. After 5 full runs of the program there was no error!! So it appears that I either have a bad breakout board or a bad parallel cable. It appears that when both pins 2/3 and and pins 4/5 are connected, there is some type of coupling or cross talk.

I tried to wire direct and am unable to get things to work. I wired the pins from the parallel cable for step and dir directly to the Gecko driver. I then tried to use the USB 5V for the common connection on the Gecko driver but no luck. I even connecting to pin 18 on the parallel cable. I certainly don't understand how the 5v reference is suppose to be wired in regard to the parallel pins.

Sage, yes, my troubleshooting skills are lacking in regard to electronics. Way over my head but I do thank you for the suggestions along with everyone else that has helped. This has been an invaluable source for me.

Best Regards.

Carl

Carl,

    You should get in touch with Arturo at CNC4PC, and tell him of your problems, and make sure he knows how old your board is.  Rev 3.1 is pretty old (the new one I just got it Rev 7.0), and the problems you're having are very much like the ones I had with my old Rev 2.0 board.  The Rev 7.0 has been very solid.  The Rev 7.0 boards have a large number of design improvements, over the earlier ones.  I was unable to get my Rev 2.0 board to work reliably, even after doing a large amount of rework to correct its design shortcomings.
    I'm not sure I understand how you tried to directly wire the Geckos.   There should be no pin 18 connection.  No ground connection at all, in fact.  The +5V from the USB port shoudl go directly to the Common terminals of the Geckos.  The signal pins (any of 2-9) should go directly to the step/dir pins of the Geckos.  Those are the only connections you should have.

Regards,
Ray L.

Regards,
Ray L.
Regards,
Ray L.
Re: Progressive Move Error with X and Y
« Reply #98 on: August 29, 2008, 07:48:58 PM »
Rich,

Believe me, I've been trying to bypass the board for quite some time but was not have any luck and didn't want to burn things up.  I finally got Ray's recommendation to use the USB as the 5v source to work.  So with that said, I was able to use pins 2, 3, 4, 5, 6, and 7 direct with no problems.  After 10 full runs without the breakout board, there was no error.  I did not re-zero after each run either!  Just checked the dial indicators and pressed start for the next run.  I realize this was a no load test but at 40IPM I think I can finally declare success!!!!!!!!!

So I'm fairly confident I have a bad breakout board at least when using pins 4 and 5.  While I don't plan to setup a 4th axis immediately, I may eventually convert one of my Carroll Dividing Heads to CNC.  At least I now know how to direct wire if necessary.

I can't thank everyone enough.  Hopefully if I have to post again, it will be a new subject.  Here are a couple of pictures of the setup if interested.

Best Regards.

Carl

Offline Chaoticone

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Re: Progressive Move Error with X and Y
« Reply #99 on: August 29, 2008, 09:51:32 PM »
 :) Good, glad you got that hammered out Carl. Now you can start enjoying all of Machs features. Yeeeeeeee Haaaaaa.

brett
;D If you could see the things I have in my head, you would be laughing too. ;D

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