Motor idle noise ?

nraynaud

oops, I just changed my power supply from 12 to 24V, and now I have noisy idle motors too. What's funny is that the volume changes with the position, I suspect it's the microstep position I'm hearing.
I have an anycubic i3, here is a picture of the motors:

here is my configuration:

; Configuration file for Duet WiFi (firmware version 1.17 to 1.19)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Wed Nov 15 2017 23:36:04 GMT-0700 (MST)

; General preferences
M111 S0 ; Debugging off
G21 ; Work in millimetres
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves
M555 P2 ; Set firmware compatibility to look like Marlin
M208 X0 Y0 Z0 U0 S1 ; Set axis minima
M208 X210 Y210 Z200 U200 S0 ; Set axis maxima

;DUAL Z
M584 X0 Y1 Z2:3 U3 E4 P3

; Endstops
M574 X1 Y1 Z1 U1 S0 ; Set active low endstops
M558 P0 X0 Y0 Z0 H2 F60 T6000 ; Set Z probe type to switch, the axes for which it is used and the dive height + speeds
G31 P600 X0 Y0 Z0 ; Set Z probe trigger value, offset and trigger height
M557 X15:195 Y15:195 S20 ; Define mesh grid

; Drives
M569 P0 S1 ; Drive 0 goes forwards
M569 P1 S0 ; Drive 1 goes backwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M569 P4 S1 ; Drive 4 goes forwards

; M350 X32 Y32 Z32 E16:16 I1 ; Configure microstepping with interpolation
; M92 X160 Y160 Z800 E92.6:92.6 ; Set steps per mm
M350 X64 Y64 Z64 U64 E16:16 I1 ; Configure microstepping with interpolation
M92 X320 Y320 Z1600 U1600 E92.6:92.6 ; Set steps per mm
M906 X1100 Y1100 Z800 U800 E1000:1000 I50 ; Set motor currents (mA) and motor idle factor in per cent
M84 S2 ; Set idle timeout

M566 X600 Y600 Z12 U12 E300:300 ; Set maximum instantaneous speed changes (mm/min)
M203 X30000 Y30000 Z1200 U1200 E1800:1800 ; Set maximum speeds (mm/min)
M201 X2500 Y2500 Z500 U500 E3000:3000 ; Set accelerations (mm/s^2)

; snip -----8<---- 8<---

The irony that I wanted to go to 24V to reduce the noise is not lost to me...

nraynaud

Can I fiddle with the M350 command live in the web interface when the motors are running (at idle)?

I am trying to change the M350 S parameter and I don't hear a difference.

fma

@dc42, what registers are set when using I999? And what params affect the motor noise?

dc42

@nraynaud said in Motor idle noise ?:

Can I fiddle with the M350 command live in the web interface when the motors are running (at idle)?

I am trying to change the M350 S parameter and I don't hear a difference.

I would not expect the M350 settings to make a different when the motors are not moving.

dc42

@fma said in Motor idle noise ?:

@dc42, what registers are set when using I999? And what params affect the motor noise?

See this thread https://forum.duet3d.com/topic/5392/does-m906-set-rms-or-peak-current. The TOFF parameter appears to be the most important one.

fma

Thanks! I will ask further questions on this thread...

nraynaud

@dc42 yes, I realize it's not smart. decay is all about the end of the step.

is there a parameter that randomizes the microstep PWM frequency? I don't know what it would be called, dithering or spread spectrum or something of the like.

dc42

@nraynaud said in Motor idle noise ?:

@dc42 yes, I realize it's not smart. decay is all about the end of the step.

is there a parameter that randomizes the microstep PWM frequency? I don't know what it would be called, dithering or spread spectrum or something of the like.

Yes there is a random off-time bit, but it doesn't seem to help much if at all.

nraynaud

I feel a bit disappointed, the silent driver is not really silent, the stall detection is not really usable to reduce the speed of the extrusion, are there other things I need to know?

dc42

@nraynaud said in Motor idle noise ?:

I feel a bit disappointed, the silent driver is not really silent, the stall detection is not really usable to reduce the speed of the extrusion, are there other things I need to know?

I'm sorry you are disappointed. Most Duet users find their printers are much quieter after upgrading the controller to a Duet.

Idle noise seems to happen most often when using 24V power and low inductance motors. As described in the other thread, reducing the TOFF time in this case often helps.

Regarding extruder stall detection, what exactly were you hoping to achieve, what did you try, and what didn't work for you?

nraynaud

@dc42 thanks, I'll try the TOFF when I feel confident about messing with the registers.

I have not tried anything with stall detection, because reading the documentation it seems that it only work at higher speed, and extruders ain't speedy. but my initial thought was to detect extrusion stall and reduce the program speed automatically. Yesterday I was printing very coarse and very fast, and the extruder started skipping and reducing the speed was enough for it go again.

dc42

You can configure motor stall detection to pause the print, see the M915 command in the GCodes wiki page. Then you could reduce the speed before you resume it. Not automatic, but it would go some way towards what you want to achieve.

UnderDoneSushi

@dc42

Hey guys,
So I actually just started converting my Printrbot Simple Metal to an E3D v6 and a Duetwifi. I am also having the stepper motor idle noise after homing. I have tried it with 2 different types of stepper motors.

Kysan - http://www.kysanelectronics.com/Products/Detail.php?recordID=7850
And an Aliexpress random - http://www.handsontec.com/dataspecs/17HS4401S.pdf

The Aliexpress stepper motor wasn't attached to the printer, it was just set up on the table and it makes the noise. Another thing I just noticed was when homing one axis by itself (Y-axis for example) the others motors make the buzz/hum after homing (probably not the extruder stepper motor). Let me know if my settings need to be provided.

wilriker

@underdonesushi said in Motor idle noise ?:

The Aliexpress stepper motor wasn't attached to the printer, it was just set up on the table and it makes the noise.

What I found in my tests it makes a lot of difference if and how the motor is attached. So testing the stepper on the table and optimizing it there will probably lead to you having to do the same tuning again after mounting the motor. Basically every change in motor setup will have an influence e.g. on the weekend I change my Z motors from wired in series to wired in parallel and I had to find a new TOFF value to make them silent in idle again.

See Reducing Stand-Still Noise for a guide on how to tune this.