Re: [CAD_CAM_EDM_DRO] Resonance in steppers

rosnekcaj wrote:

> I am losing and gaining position error as my system goes through the
> gcode I feed it. I suspect it may be due to stepper reonance. Is
> there any gcode that would pinpoint that this is the problem. In
> other words how can I find the sensitve velocity that triggers the
> resonance.

You don't mention your software, but assuming it has a feedrate
override, run the same program with different feddrate
percentages. This should scale all speeds in the program.
If the position shift is the same for multiple runs at one
speed, but varies at different speeds, that would indicate a
resonance problem. If the error seems to be really random, or
is not affected much by the feedrate override, then it may be a
step pulse to direction timing problem.

With properly tuned Gecko drives, there is so little stepper hum
that you aren't sure it is even a stepper system. With some
other drives, especially of the non micro-stepping variety, the
stepper whine is quite audible at almost any speed, and becomes
REALLY loud right near the resonance. If you hear a rising
whine followed by a loud GRRRONK noise (best I can do spelling
it out) that is resonance. If there is little whine and no
grinding noises, you probably do NOT have a resonance problem,
but either a problem with noise on the step line or a timing
problem between step and direction.

Jon