Extruder stopping mid print, fixed after reboot

Rseur · 15 Apr 2025, 08:21

Hi,

I am suddenly running into the issue described by the title. During a print (after an irregular amount of time) my extruder stepper will stop rotating. When pausing the print to manually extrude I get the warning:

"Warning: Driver 4 warning: phase A may be disconnected, phase B may be disconnected" (also happens on Driver 3)

When I reboot the Duet 2 Wifi board that I am using, everything works fine again.

I have checked to following items to see if they cause the problem but they appear to be fine:

Stepper motor (windings measure 2.2 ohms)
Bad cable (no cable break, no bad crimps, and no bad, discolored of burnt connector, checked with different cable)
Swichting TMC stepper driver (both driver 3 and 4 have this issue)

The printer has been working fine for a couple of years now. I have cooling fans for the extruder motor and Duet PCB.
I am printing at speed 45 mm/s, acceleration 1100 mm/s2, jerk 10 mm/s with a bowden setup with linear advance enabled.
Extruder motor is NEMA17 0.9 deg/step running at 900 mA with 16 microstep. (I will post full config in below)

What annoys me most is that resetting the whole board fixes it .
I found some other posts on this forum but that did not help me solve my problem unfortunately.

; Configuration file for Duet WiFi (firmware version 3.3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.3.15 on Sat Dec 17 2022 17:53:26 GMT+0100 (Central European Standard Time)

; General preferences
G90 ; send absolute coordinates...
M83 ; ...but relative extruder moves
M550 P"Dbot" ; set printer name
M669 K1 ; select CoreXY mode

M80 C"pson" ; allocates the pin and sets the pin in the power on state.
M81

; Network
M552 S1 ; enable network
M586 P0 S1 ; enable HTTP
M586 P1 S0 ; disable FTP
M586 P2 S0 ; disable Telnet

; Drives
M569 P0 S1 ; physical drive 0 goes forwards
M569 P1 S1 ; physical drive 1 goes forwards
M569 P2 S1 ; physical drive 2 goes forwards
M569 P4 S0 ; physical drive 3 goes forwards
M584 X0 Y1 Z2 E4 ; set drive mapping
M350 X16 Y16 Z16 E16 I1 ; configure microstepping with interpolation
M92 X200.00 Y200.00 Z10666.67 E315.00 ; set steps per mm
M566 X9000.00 Y9000.00 Z60.00 E1700.00 ; set maximum instantaneous speed changes (mm/min)
M203 X12000.00 Y12000.00 Z180.00 E1200.00 ; set maximum speeds (mm/min)
M201 X3000.00 Y3000.00 Z20.00 E1000.00 ; set accelerations (mm/s^2)
M906 X1200 Y1200 Z1700 E900 I30 ; set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

; Axis Limits
M208 X0 Y0 Z0 S1 ; set axis minima
M208 X370 Y330 Z300 S0 ; set axis maxima

; Endstops
M574 X1 S1 P"!xstop" ; configure switch-type (e.g. microswitch) endstop for low end on X via pin !xstop
M574 Y1 S1 P"!ystop" ; configure switch-type (e.g. microswitch) endstop for low end on Y via pin !ystop
M574 Z1 S1 P"!zstop" ; configure switch-type (e.g. microswitch) endstop for low end on Z via pin !zstop

; Z-Probe
M950 S0 C"exp.heater3" ; create servo pin 0 for BLTouch
M558 P9 C"^zprobe_in" H5 F120 T6000 ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X-30 Y2 Z1.83; set Z probe trigger value, offset and trigger height
M557 X30:330 Y30:300 S75 ; define mesh grid

; Heaters
M308 S0 P"bedtemp" Y"thermistor" T100000 B3950 ; configure sensor 0 as thermistor on pin bedtemp
M950 H0 C"bedheat" T0 ; create bed heater output on bedheat and map it to sensor 0
;M307 H0 B1 S1.00 ; enable bang-bang mode for the bed heater and set PWM limit
M307 H0 R2.445 K2.543:0.000 D5.36 E1.35 S1.00 B0
M140 H0 ; map heated bed to heater 0
M143 H0 S120 ; set temperature limit for heater 0 to 120C
M308 S1 P"e0temp" Y"thermistor" T100000 B4275 C7.06e-8 ; configure sensor 1 as thermistor on pin e0temp
M950 H1 C"e0heat" T1 ; create nozzle heater output on e0heat and map it to sensor 1
;M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit
M307 H1 R1.895 K0.337:0.000 D5.08 E1.35 S1.00 B0 V11.8
M143 H1 S280 ; set temperature limit for heater 1 to 280C

; Fans
M950 F0 C"fan0" Q25000 ; create fan 0 on pin fan0 and set its frequency
M106 P0 S0 H1 T45 ; set fan 0 value. Thermostatic control is turned on
M950 F1 C"fan1" Q500 ; create fan 1 on pin fan1 and set its frequency
M106 P1 S1 H-1 ; set fan 1 value. Thermostatic control is turned off

; Tools
M563 P0 D0 H1 F0:1 ; define tool 0
G10 P0 X0 Y0 Z0 ; set tool 0 axis offsets
G10 P0 R0 S0 ; set initial tool 0 active and standby temperatures to 0C

Phaedrux · 16 Apr 2025, 05:51

Firmware version?

@Rseur said in Extruder stopping mid print, fixed after reboot:

checked with different cable

Phase disconnected usually means what it says, so I would suspect an intermittent break in the cable, especially seems likely if the cable chain has been in use for a long time. But you say you've tested with a new cable?

Rseur · 17 Apr 2025, 07:50

@Phaedrux

I am running with version 3.4.5:
FIRMWARE_NAME: RepRapFirmware for Duet 2 WiFi/Ethernet FIRMWARE_VERSION: 3.4.5 ELECTRONICS: Duet WiFi 1.02 or later FIRMWARE_DATE: 2022-11-30 19:36:12

I tested with a different cable from another motor to see if it would trigger the same warning on the extruder motor. It did again today. Could be that both cables are bade I guess. So I'll make two new motor cables later today to see if that helps.

The printer is a coreXY Dbot adaption that looks a bit similar to yours. All motors are fixed to the frame and there shouldn't be to much movement on the cables.

dc42 · 17 Apr 2025, 08:25

@Rseur as a general rule, if RRF reports just one motor phase may be open circuit, that usually indicates a wiring issue. If RRF suddenly reports both phases open circuit, then it's likely that the driver has shut down. This could be because it has overheated. In that case it should have reported over-temperature first; however there was at least one version of RRF in which drive rover-temperature reporting stopped working.

As you are running the extruder at a low current, it's unlikely that the driver has overheated. So I am wondering whether there has been an electrostatic discharge event that has triggered the short circuit detection in the driver. Extruding plastic generates static electricity and we know that ESD at the extruder has caused malfunctions in the past.

I suggest you make sure that the extruder motor body is connected to Duet ground (or VIN- which is the same thing). That will prevent static build-up on the extruder motor body, which would be likely to arc across to the stepper phase connections.

droftarts · 17 Apr 2025, 16:27

@Rseur See notes on grounding here: https://docs.duet3d.com/en/User_manual/Connecting_hardware/Power_wiring#grounding

Ian

Rseur · 20 Apr 2025, 17:45

@dc42 @droftarts

Thanks so much for your replies!

I hadn’t grounded the extruder motor casing or hotends yet, seems I missed that detail when I first built the printer. Looking back, it totally makes sense to ground those parts . It does make me wonder what’s changed recently that’s now causing ESD issues, when everything was fine before.

For now, I’ve attached a grounding wire to one of the casing screws on the back of the extruder stepper motor. I haven’t had time yet to ground the hotend properly in a non-janky way, so I will do that later (or when the issue remains I guess)

I’ll be printing the same model a few more times, so I’ll see if grounding just the stepper resolves the issue and report back.

Thanks again for the help

Rseur · 23 Apr 2025, 18:03

Good news!

I printed 3 more of the same 3D model (22 hour print ~500g of plastic PETG) and I have not had this failure since grounding the casing of only the extruder motor. So it seems that the issue was indeed ESD on the stepper driver causing it to go into a failure mode.

Thank you very much for your time and help!