Random Pulses to Motors when Idle

[offthewall]

I’m getting random pulses to my steppers when my machine sets idle, and sometimes when I’m running a part. Seems to be in the X axis, and every now and then in the Y axis. I’m running a Taig machine with their step & direction add on board with Mach 3. Could it be a setting in Mach 3, or shoould I be looking somewhere else. It moves the axis slightly when it gets the surge.

Thanks for looking.
Steve

[ger21]

Run the mach3 driver test (drivertest.exe) and see if you get a flat line. It could be a windows service causing glitches n Mach3.

[Zappautomation]

May also be electrical noise, are you using shielded cables for the signals?

I’m getting random pulses to my steppers when my machine sets idle, and sometimes when I’m running a part. Seems to be in the X axis, and every now and then in the Y axis. I’m running a Taig machine with their step & direction add on board with Mach 3. Could it be a setting in Mach 3, or shoould I be looking somewhere else. It moves the axis slightly when it gets the surge.

Thanks for looking.
Steve

[neilw20]

While it is sitting idle and pulsing occasionally, unplug the parallel cable.
If it stops, blame signal levels.
Bet if you exit Mach3 with the cable in you will soon rule out Mach3 causing the problem.
Mach3 is ROCK SOLID.
You have some form of earthing problem.
Try a different cable. Some cables are poorly made and skimp on earth circuits.
3.3v signal levels from later PC also erode the noise margin.

[offthewall]

Thanks for all of the suggestions. I did run the drivertest.exe, and although I didn’t get a dead flat line the variance was from low of 38 and a high of 45. When you say shielded cables, do you mean the parallel cable, or the motor cables? I will try all of the great suggestions.

Thanks Again!!

[neilw20]

PC cable should be shielded to stop interference corrupting your control signals.
No gain will be had by shielding your motor cables for your problem.

[offthewall]

Thanks Neil. I’ll switch that out with a shielded cable.

Steve

[neilw20]

If you are getting random pulses when stationary, you can straight away split the problem by un plugging the cable.
If you get no random pulses with the cable unplugged, then they are probably not being introduced by the machine.
Plug the cable back in and unplug it from the PC.
Still good? If no, blame the Machine/Cable combination.
Yes, start to blame the PC.
Conquer and destroy.
Each result is not always 100%. Don't just think 'THERE IT IS!'
Because results can be less than 100% then the decisions must be too.
Don't just jump to conclusion you need a new cable.
It is more likely an earthing problem, and have to eliminate one section at a time.
Trying things just leads (no pun intended) to error. Analyze the problem and you WILL fix it.