Motors make noise in stealthchop, but not in spreadcycle

micheldb14

My motors are making a rattling sound when I'm using them in stealthchop mode. I have made 2 videos so you can hear it (it's louder in real life).

Stealthchop (tpwmthrs 40 (187.5 mm/sec)):
https://youtu.be/2dgEB6JUaco

Spreadcycle (tpwmthrs 1000000 (0.0 mm/sec)):
https://youtu.be/saUcV5DO0IA

The gcode im running just moves my X axis left and right at speeds from 30-120mm/s in steps of 10 mm/s

In the first video (stealthchop) the first pass (30mm/s) is really silent, the second pass(40mm/s) adds a bit of a rattling sound and the third pass(50mm/s) makes an really annoying rattling sound. at the higher speeds the sound is less again.

When I set the motors to spreadcycle only (tpwmthrs 1000000 (0.0 mm/sec)) the rattling sound is gone.

The motors I use are :

Model No.: 17HS4401
Step Angle: 1.8 deg.
Motor Length: 40 mm
Rated Current: 1.7 A
Phase Resistance: 1.5 Ω
Phase Inductance: 2.8 mH
Holding Torque: 40 N.cm
Detent Torque: 2.2 N.cm
Inertia Of Rotor: 54 G. cm²
Lead: 4

Does someone know how I can fix this?

Veti

do you have 24v or 12v? for stealthchop2 you really want 24v

micheldb14

My power supply is 24V.

Veti

it could be that you are hitting a resonating frequency in stealthchop mode.

things to try.
nema Motor Vibration Damper. (either rubber or cork versions)
different nema motors.

micheldb14

I have tried another type of stepper motor and it does the same thing.
https://youtu.be/G53r7m0D6W4 (ignore the sounds of the belt)

Isn't there a way to change the frequentie in the software or something?
I would like to stay away from dampers if it isnt really nessesary

Veti

stealthchop is doing autotune on the first move.

then those values are stored in the chopper control registers. (C value of M569)

i have not played around with those myself,

micheldb14

I still have the same problem so all help is still welcome!

micheldb14

@Veti
I can't find anything about this on internet. Also I can't really see a C value in my M569 commant.
this is what my M569 reports:
M569 P0: Drive 0 runs in reverse, active low enable, step timing fast, mode stealthChop, ccr 0x00053, toff 3, tblank 0, hstart/hend/hdec 5/0/0, tpwmthrs 1000000 (0.0 mm/sec)