Axis Stops Working

[trwalters001]

Hi All,
I'm running a laser cutter with Mach3 connected directly to a G540. Desktop PC with video card, no other programs running. Drive Test says all is well.
I've got a couple of Gcode files that I'm testing with. One draws a square and the other draws an interpolated circle with G2. I can bring up the system, load in either file and it works great. However, if I change feed rates in the Gcode or jog to a new position, quite often the Y-axis stops working. Jog continues to work fine. If I quit Mach3 and restart it, sometimes the axis starts working again, sometimes not. If I reboot the PC and then restart Mach3, MOST of the time things start working again. In all cases, jog continues to work correctly after the axis quits working under program control. The only other piece of info I have is that it sounds like the X-axis has changed feed rate once the Y-axis stops working. Jog, however sounds right.
I hope someone has some ideas!
Thanks for any advice,
Tim Walters

[Tweakie.CNC]

Perhaps a fresh install of Mach may be the first thing to try.
Initially just try re-installing over the top of the existing version and if that does not cure it then uninstall, delete all traces, having made backup copies of you license .dat and .xml files etc. then a fresh install.
That's what I would try.

Tweakie.

[Hood]

My guess would be you may have a slow jog set so when jogging it is fine but as you feed faster in the code the axis will be going faster than you are jogging and it is stalling. This would indicate your motor tuning is set to aggressively so possibly look at slowing down the Velocity and Acceleration.

Other than that it could be you have the kernel set higher than you need and the pulse is getting poor the faster you jog or you drives may be needing a wider pulse so Sherline mode may help.
Hood

[Hood]

Last part should heave read
 "kernel set higher than you need and the pulse is getting poor the faster you feed with multiple axis

[trwalters001]

Thanks to both of you!
I'll give those things a try as soon as I get home.
Tim

[trwalters001]

Hi All,

Again; thanks VERY much for your help. I wish I could buy you a pint or 6...

I tried the suggestions both of you gave, but no joy. Here's some more info. This is to be added to what I said earlier.

-My kernel speed is 25KHz.
-The DROs and toolpath display work correctly (showing both axes moving even when one axis is not physically moving.)
-The X-axis is definitely changing to a different velocity and acceleration when the Y-axis stops working.
-If I quit Mach3 and restart, it usually takes 2 tries of clicking the desktop shortcut for Mach3 to start again. The 1st attempt seems to be ignored.
-I have found that sometimes the Y-axis continues to work but is considerably out of sync with the X-axis. IOW, if I try to draw my circle, the Y-axis doesn't start moving at all until the X-axis is many degrees into the circle.
-Several times, after successful tries drawing the circle, I could wait a few minutes and try again and the Y-axis had quit working.
-Once the problem showed up, Driver Test would report "Pulsing too fast" before Mach3 took over, and then "System Excellent" afterwards.
-The version I was running was 3.42.40. I installed 3.43.22 over the top of it.
-Each time the problem showed up, I could install the latest version and things would operate correctly for several tries, then goof again.
-I slowed down both axes to 125 IPM with low acceleration. My feed rate is set to 30.
-I have not tried uninstalling Mach3 completely and reinstalling. I'll try that next unless I get different advice.

Thanks again,
Tim

[derekbpcnc]

Hii Tim,

Have you gone through the optimisation steps for XP?
Link here  http://www.machsupport.com/downloads/XP_Optimization.txt



My PC was running like a bag of nails till I did the optimisation and the step below had the greatest effect (for me anyway).
...but go through from the start of the doc linked above....

good luck
Derek.

1. Right Click My Computer and select Properties
2. Click Hardware tab.
3. Click Device Manager Button in the middle.
4. Double click "Computer".
5. Right click on Standard ACPI PC and choose Update Driver.
6. Choose "Install the software from a Specific Location (Advanced)"
7. Click Next.
8. Choose "Don't search. I will choose driver to install."
9. Click Next.
10. Choose "Standard PC" from the listing.
11. Click Next.
12. Click OK.

[Hood]

From your description the axis is stalling.
Have you tried Sherline mode?
Have you checked the voltage being supplied to your drives when axis are moving?
Can you swap X and Y drives around to see if the issue follows the drive?
Is the line in the driver test flat or does it have spikes?

Hood

[trwalters001]

Thanks Derek & Hood,

I've already gotten rid of the ACPI stuff...

I did some research on the Sherline mode. This may be the problem.

The problem with the G540 inputs was discovered and talked about at length in mid-2009. That's the same time I purchased my G540.

There's a very good chance that I have one of the 3% that exhibit the problem.

I'll put it in Sherline mode tonight and see what happens. I've got a "gut feeling" that that's the fix.

(Hood - the Driver Test line is flat with very few, small spikes. If the Sherline mode doesn't fix the problem, I'll swap X & Y and check it out.)

Thanks again!

Tim

[trwalters001]

Hi All,

Apparently, Sherline mode has fixed the problem. Not a single goof in a continuous half-hour of changing feed rates, jogging, different files, anything I could think of.

I really appreciate the assistance from you guys.

Tim