Extruder whirring after Maestro to Mini 5+ upgrade

j3d · 9 Mar 2021, 02:10

Hi everyone,

I've recently upgraded my Duet Maestro to a Mini 5+ after the ethernet controller died. One thing that I haven't been able to figure out is that the extruder motor now makes a strange whirring noise when extruding. This didn't happen on the Maestro, and I suspect it's caused by the change in stepper drivers between the two models.

Video: https://www.dropbox.com/s/xkfhbbf8rjpr45w/extruder_whirring.mov?dl=0

I've tried switching it into spread cycle mode, however the idle noise was driving me crazy, so I switched it back. I assume this is something to do with the driver switching between spreadcycle and stealthchop? The X and Y motors are the same model, and they don't seem to have the issue, so it seems like it arrises when running at a low step rate.

My config is straight-forward:

 M569 P0.0 S1                                ; physical drive 0.0 goes forwards
M569 P0.1 S1                                ; physical drive 0.1 goes forwards
M569 P0.2 S1                                ; physical drive 0.2 goes forwards
M569 P0.3 S1                                ; physical drive 0.3 goes forwards
M584 X0.0 Y0.1 Z0.2 E0.3                    ; set drive mapping
M350 X128 Y128 E64 I0                       ; configure microstepping without interpolation
M350 Z16 I1                                 ; configure microstepping with interpolation
M92 X711.00 Y711.00 Z400.00 E400.00         ; set steps per mm
M566 X900.00 Y900.00 Z12.00 E120.00         ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z360.00 E1200.00     ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z50.00 E250.00         ; set accelerations (mm/s^2)
M906 X800 Y800 Z320 E800 I30                ; set motor currents (mA) and motor idle factor in per cent
M84 S30                                     ; Set idle timeout

The video shows a 50mm extrusion at 5mm/s.

Motor specs:
Voltage: 4.96V
Current: 0.8A
Resistance: 6.2 ohms
Inductance: 10mH
Torque: 2.4 Kg*cm

I'm running on a 24V supply.

Has anyone run into this before?

Phaedrux · 9 Mar 2021, 03:13

@j3d said in Extruder whirring after Maestro to Mini 5+ upgrade:

M350 X128 Y128 E64 I0

Why do you have interpolation disabled? The drivers in the mini5 allow interpolation from any microstepping level, so might as well make use of it.

Also I'd be careful of increasing the microstepping anyway. Check M122 and look for the hiccup count. It should be 0. If you notice more than a handful of hiccups over the course of the print you're likely missing steps and should reduce the microstepping amount. You're really not gaining anything beyond x16 anyway unless it's a very low steps per mm axis to begin with. Perhaps your extruder is.

j3d · 9 Mar 2021, 03:53

Sorry, I included the incorrect config. Here's what's on my board:

 M569 P0.0 S1                                ; physical drive 0.0 goes forwards
M569 P0.1 S1                                ; physical drive 0.1 goes forwards
M569 P0.2 S1                                ; physical drive 0.2 goes forwards
M569 P0.3 S1                                ; physical drive 0.3 goes forwards
M584 X0.0 Y0.1 Z0.2 E0.3                    ; set drive mapping
M350 X16 Y16 Z16 E16 I1                     ; configure microstepping with interpolation
M92 X88.87 Y88.87 Z400.00 E400.00           ; set steps per mm
M566 X900.00 Y900.00 Z12.00 E120.00         ; set maximum instantaneous speed changes (mm/min)
M203 X12000.00 Y12000.00 Z720.00 E1200.00     ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z50.00 E250.00         ; set accelerations (mm/s^2)
M906 X800 Y800 Z320 E800 I30                ; set motor currents (mA) and motor idle factor in per cent
M84 S30                                     ; Set idle timeout

Hiccups for both MainDDARing and AuxDDARing are 0.

Diamondback · 9 Mar 2021, 11:13

I'm interested in this as well. I revived an old CR-10 Mini with a Duet 3 Mini and notice the same weird sound effects, but on all axis. It goes away beyond a certain moving speed, but esp during homing the second time (using smaller speeds) it is very obvious (in addition to the extruder)
As j3d mentions, the sound goes away with using SpreadCycle, but then the idle noise of the motors is incredibly loud.

jay_s_uk · 9 Mar 2021, 11:16

try adding D3 V40 to the M569 command for the affected motors.
Even though the default is stealthchop, RRF has a very low switching speed

j3d · 9 Mar 2021, 22:59

@jay_s_uk That worked great! Will this affect the torque curve? How did I know if this value is too low/too high? I guess by looking at the steps/mm output when you run M569 Px?

jay_s_uk · 9 Mar 2021, 23:00

@j3d you should be fine as running in stealthchop is fairly typical

Veti · 10 Mar 2021, 05:06

since your motors are rated at 0.8A they will get hot when you run them at at.
reduce the current to about 75% of the rated current.

also for extruder i found that spreadcycle produces better results.

i run all my stepper in stealthchop except the extruder.

	M569 P0.0 S1 ; physical drive 0.0 goes forwards
	M569 P0.1 S1 ; physical drive 0.1 goes forwards
	M569 P0.2 S1 ; physical drive 0.2 goes forwards
	M569 P0.3 S1 ; physical drive 0.3 goes forwards
	M584 X0.0 Y0.1 Z0.2 E0.3 ; set drive mapping
	M350 X128 Y128 E64 I0 ; configure microstepping without interpolation
	M350 Z16 I1 ; configure microstepping with interpolation
	M92 X711.00 Y711.00 Z400.00 E400.00 ; set steps per mm
	M566 X900.00 Y900.00 Z12.00 E120.00 ; set maximum instantaneous speed changes (mm/min)
	M203 X6000.00 Y6000.00 Z360.00 E1200.00 ; set maximum speeds (mm/min)
	M201 X500.00 Y500.00 Z50.00 E250.00 ; set accelerations (mm/s^2)
	M906 X800 Y800 Z320 E800 I30 ; set motor currents (mA) and motor idle factor in per cent
	M84 S30 ; Set idle timeout