The uc100 seems to be a good well supported motion controller, I would suggest if possible to try to reduce the controller frequency from 100khz to maybe 50khz, given even if you changed the ustep resolution to 10ustep, that has a maximum frequency of only about 33khz.

You can try other things like 10ustep resolution although that will double your steps per unit to 5080... that may help with resonance... but I don't think it will help with maximum velocity or acceleration


Also check your lookahead is set to about 200 lines on the general configuration tab.

What version of Mach3 are you using?
0.66 is not favoured....install 0.62 although difference I believe is in the control of mpgs... but worth a shot

Rob

Should read .... 5080 x 2 = 10160 steps per unit....

I will give those suggestions a try and see how it behaves!

I've set the UC100 to 50kHz, works fine. Haven't notice a difference between 100kHz or 50kHz.

For step and dir pulse settings to 20, it doesn't let me set it higher. It reverts back to 15?

Micro steps are usually set with DIP switches on the stepper driver module, but it sounds like you're trying to change this in a configuration screen.  Try adjusting it on the driver module itself.

Stephen "Highspeed" Kruse

It was the pulse width that was being discussed not microsteps

Ah, ok. Thanks.

Highspeed

I know its an old thread, but my question is kinda same and I dont want to start a new thread.
I use a common PRC 5axis bob, with 25khz, and 2M542 drivers, 48V power supply and a bit smaller motors than the OP - 2phase, 3.08V, 2.8A, resistance 1.1, inductance 3.6, 1.89 Nm. No matter how I tune it in motor tuning - slow like 400 mm/m or 1200 mm/m, and no matter what accel, they stall after a while, loosing steps. I chose half current. I am aware that the 48V power supply isnt the best choice for these motors, but thats what I got.
I did set them to 5 micro steps, leadscrew is 2.5mm, 1000 steps per min, multiplier is 2.5 (belt). I tried all possible combinations in motor tuning with step pulse 1-5 and dir 0-5 (not over 5), but no luck. stalling.
I would like to get the fastest rapids possible, cutting feeds have to be slow. but to wreck every part I tried to make for like 10 days......its frustrating.
Thanks for help

Hi,
it sounds like you have experimented enough with the steppers and drivers to be reasonably confident that the fault is not the steppers/drivers. You may have to
revisit that decision but maybe you should consider other possible faults.

You haven't specified that you are using a parallel port, I don't know anything about your 'common PRC BoB', but will presume it has parallel port input. If that is the case
then if the parallel port is stalling or stuttering in any way missed steps and outright stepper motor stalls result.

May I suggest run DriverTest.exe and post the results, 'Good or Excellent' is not an adequate report, we need to see either the graphic line and/or the numbers describing the jitter.
A screen shot is good. Use the 'Additional Options' to the lower left of the text input pane to attach and preference is that you use Paint or similar to scale the image to around 600kB.

Craig

dont have the internet in my shop, so I took a pic.
common prc bob, cheap 5axis breakout board that is sold on ebay. I use the same bob, drivers and steppers on my mini lathe, and its under linuxcnc, with 1200 mm/min rapids. on my mill, I cant go over 500 mm/min without the stalling.