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Help with servo motor tuning needed!
Hi there
Having gotten fed up struggling with Mach3 Probing issues I am giving Simcnc a go, This is on a Plasma table.
The X axis auto tuned fairly easily, however the Y axis will not autotune, which was also the case in Mach3, I did read at the time that rack and pinion can be difficult for auto tuning.
I did get all axis's tuned reasonably well manually within the csmio pluggin in Mach3, but unfortunately those numbers do not seem to translate into SimCnc.
I did have my servo drives set up for torque control mode, but saw in Simcnc manual, encoder output section that I should be using Speed control mode?
I did make the switch to speed control, and re-tuned the servo drive, and then tried auto tuning in Sincnc, which did seem less violent,
but is still unsuccessful in completing autotuning, it just gets stuck raising Vaff (i think! the one on the right of the autotuning screen) , it will just keep raising that until i cancel autotuning.
The result is massive overshooting of the axis.
Any Tips on how to manually tune the motors?
"tried auto tuning in Sincnc"
Hello, I am an amateur in CNC, I also have Chinese servos. I have a question: when you talk about auto-tuning, is it on your servo controller that it is done? Because in SimCNC, unless I am mistaken, there is no "auto."
There is an auto tuning for axis/ motors in Simcnc, at the bottom of the configuration tab, it worked well for x axis, Y axis seems more difficult as it is a rack and pinion type.
My servo drive has its own auto tuning function also. You have to get the servo drive tuned correctly first before trying to tune your control software
But i think i have found a large part of the problem, although auto tuning in my servo drives software appeared to work, i was able to make vast improvements tuning manually, small increments at a time in the servo drive, and then switching back to mach3 PID tuning,
I think my Z axis servo drive was tuned far too gently if that makes sense, and was causing PID faults as the drive was reacting too slow to what mach3 and simcnc where expecting.
Although I now have another problem that the drive starts creeping as soon as its powered up, but only when its in Velocity mode, it doesn't do it in Torque mode for some reason, which is unfortunate as it seems much much smoother in Velocity mode.
Man... I didn't see autotune since now... I'll try that tomorrow.
I'm not sure what you mean by "drive start creeping"; my servo starts to make noise when the "position loop gain" in my driver is too high." (For my case, high value = more responsive position.)
diden't have torque mode or Velocity mode
Quote from clifford Bichan on 28 April 2024, 16:26
>>> I did get all axis's tuned reasonably well manually within the csmio pluggin in Mach3, but unfortunately those numbers do not seem to translate into SimCnc.
>> I did have my servo drives set up for torque control mode, but saw in Simcnc manual, encoder output section that I should be using Speed control mode?
The CSMIO/IP-A controller only works with drives operating in velocity mode.
>> but is still unsuccessful in completing autotuning, it just gets stuck raising Vaff (i think! the one on the right of the autotuning screen) , it will just keep raising that until i cancel autotuning.
This means that your axis is not very sensitive to sudden accelerations.
This may be caused by enabled speed filters in the drive or too soft tuning.
Quote from clifford Bichan on 28 April 2024, 16:26Any Tips on how to manually tune the motors?
This is a very extensive topic that cannot be covered in a few sentences.
Please see the article for Mach4, it is virtually identical to simCNC:
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