Microstep Settings for High Resolution Stepper Motors

[bLiTzJoN]

I picked up some .45 deg steppers for a delta printer upgrade. All seems to be fine keeping at 1/16 with interpolation enabled:

M350 X16 Y16 Z16 E16 I1;
M92 X320.00 Y320.00 Z320.00 E410.00;

I'm wondering if I should consider changing my settings, or even disabling interpolation given the resolution. Thoughts? They are a bit noisy when homing. I'm still calibrating and haven't tried printing anything yet.

[bLiTzJoN]

I lowered my homing speed from 1800 to 1200 and that seemed to quiet down considerably. Perhaps some speed values cause some harmonics.

[T3P3Tony]

@blitzjon As far as I know not many (or maybe any) people here have experience with those motors. As a general rule we recommend using interpolation for noise reduction rather than to increase accuracy. As the interpolation is done in the stepper driver there is no performance downside to enabling it. It will be interesting to see if you get a noticeable difference with and without it enabled using these motors.

[engikeneer]

@blitzjon I think you've hit the midband resonance of your steppers there. From my understanding, that is a speed related resonance determined by the motor and the system its connected to, not a torque ripple that high microstepping/interpolation can deal with. Someone who knows more might be able to explain it a bit better....

[T3P3Tony]

@engikeneer @bLiTzJoN

if it is mid band resonance there is a good description here:
https://www.geckodrive.com/support/step-motor-basics/mid-band-instability.html