Viesturs trešd., 2026. g. 6. maijs, plkst. 16:10 — lietotājs Marco (<[email protected]>) rakstīja: > > On Wed, 6 May 2026 12:09:21 +0100 > andy pugh <[email protected]> wrote: > > > This typically means that the scales are set wrongly so that more > > steps per second are being requested than are physically possible > > within the constraints of the step length and step space. > > I've set > > # X, Y > STEP_SCALE = 320 > # Z > STEP_SCALE = 400 > > That should be correct for my machine. But maybe not. I've tried to > adapt the default values to match my machine to the best of my > ability. My current INI and HAL are attached. > > I'm a bit confused about the PID stuff. My steppers don't have any > sort of feedback. How can a PID work without feedback? Is that PID > code even required for my setup? I've tried to uncomment it, but the > issue remains. So maybe it has nothing to do with that. > > The actual problem (on all axes) is that I can jog once, twice maybe > three times and then get: > > joint 0 following error > emc/task/taskintf.cc 976: Error on joint 0, command number 108 > > The command number changes every time and of course the joint number > if I try jogging the other axes. Any ideas? >
I tried some quick maths and theoretically your step length and step space should be fine for your scale and maxvel (1 step = 10 us, so 1 mm = 320 steps = 3200 us = 3.2 ms and theoretical maxvel at this timing is 1000/3.2 = 312.5 mm/s). First thing I would check is making sure that the drives are happy with the increased step frequency you are reaching - reduce microstepping and step_scale accordingly as well as steplength and stepspace. Second thing is about PID parameters - IMHO P=300 will not be correct (and the behavior you describe makes sense - actual following error accumulates until it reaches the limit). Increase ferror and min_ferror by a factor of 10 or even 100 and check if you can jog for larger distances. This thread seems relevant about PID and open loop steppers: https://www.forum.linuxcnc.org/38-general-linuxcnc-questions/31046-open-loop-stepper-pid Viesturs _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
