I am using a 12V supply. I think you're right about it being related to supply voltage. As a test, I turned the trim pot on my supply to 16V and played with the x - motor. At a current of 2000mA was able to comfortably get the x - motor to move at 23 rev/sec; about 180 mm/s on my machine.

If I remember the behavior of inductors correctly, my y - motors are now getting 6 V each and I should be able to get 12V to each motor if I rewire them to be in parallel. I'm going to look into either rewiring them or or getting a 24V power supply.

I just got my DuetWifi up and running, and have had several very successful prints. But I am having some issues with torque on my motors, and can't seem to find a post that answers my question.

Background and Details

• Lead screw driven cartesian machine, fully custom built.

• DuetWifi running firmware 1.17e, WiFi server 1.02, and Web interface 1.12-RC1

• x and y motors are model 17hs19-2004s1. Single motor in the x axis using drive 1 and two motors in the y axis in series using drive 2.

• z motor and extruder motors are model 17hs13-0404s. single z motor and single E motor for dual extruders.

Current speed, acceleration, etc settings:
M569 P0 S1 ; Drive 0 goes forwards
M569 P1 S0 ; Drive 1 goes forwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M569 P4 S1 ; Drive 4 goes forwards
M584 X1 Y2 Z0 E4:3 ; Apply custom drive mapping
M350 X16 Y16 Z16 I0 ; Configure microstepping without interpolation
M350 E16:16 I1 ; Configure microstepping with interpolation
M92 X400 Y400 Z1600 E418.5:418.5 ; Set steps per mm
M566 X15 Y15 Z1200 E120:120 ; Set maximum instantaneous speed changes (mm/min)
M203 X4000 Y4000 Z300 E1200:1200 ; Set maximum speeds (mm/min)
M201 X250 Y250 Z250 E250:250 ; Set accelerations (mm/s^2)
M906 X1600 Y1600 Z800 E800:800 I30 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

My Question
My motors (all of them) seem to lose all torque at any speed higher than 3.75 rev/s. I have tried all microstep options, tried increasing and decreasing my current, and even tried removing all load from the motors. Even under no load (other than internal friction), the motors stall and skip, sometimes turning backwards. I have the motors wired exactly as pictured in the wiki.

My theory is this is related to the TMC2660's stallguard feature, which is heavily outlined in its datasheet. However, I can't find a way to set the parameters of that here on duet3d.com.

Any help or advice would be greatly appreciated.