gap fill causes stepper to spasm

  • I have an issue where the extruder stepper cannot push filament on small rapid movements, like gap fills between thin walls. MCU temp doesn't exceed 47 degrees. Walls look smooth. I can see the stepper throwing itself back and forth sporadically, unevenly, when it tries to do gapfills. The same slicer used with this print had no issues with two other printers. Extruder used is a zesty nimble.

  • Hi,

    A Zesty Nimble should work fine on a Duet. I have two printers setup with Nimbles and am they work very well.

    But we need more info on your printer and your firmware settings.

    Please post your config.g file and the info about the related hardware, like the stepper motor.


  • Stepper is a standard, boring stepper. No distinctive markings, labels or form factor.

    ; Configuration file for Duet WiFi (firmware version 1.20 or newer)
    ; executed by the firmware on start-up
    ; generated by RepRapFirmware Configuration Tool on Wed Jul 25 2018 20:40:36 GMT-0400 (EDT)
    ; General preferences
    G90                                  ; Send absolute coordinates...
    M83                                  ; ...but relative extruder moves
    M555 P0                              ; Set firmware compatibility to look like native output
    ;*** The homed height is deliberately set too high in the following - you will adjust it during calibration.
    ; M665 R132.4 L266.7 B115 H250.7             ; Set delta radius, diagonal rod length, printable radius and homed height
    M665 R129 L266.7 B116 H253
    M666 X0 Y0 Z0                        ; Put your endstop adjustments here, or let auto calibration find them
    ; Network
    M550 PRanKossel                      ; Set machine name
    M552 S1                              ; Enable network
    ;*** Access point is configured manually via M587
    M586 P0 S1                           ; Enable HTTP
    M586 P1 S0                           ; Disable FTP
    M586 P2 S0                           ; Disable Telnet
    ; Drives
    M569 P0 S0                           ; Drive 0 goes backwards
    M569 P1 S0                           ; Drive 1 goes backwards
    M569 P2 S0                           ; Drive 2 goes backwards
    M569 P3 S0                           ; Drive 3 goes backwards
    M569 P4 S0                           ; Drive 4 goes backwards
    M584 X0 Y4 Z2 E3		     ; reassign tower B stepper due to stalling
    M350 X16 Y16 Z16 E16 I1              ; Configure microstepping with interpolation
    M92 X80 Y80 Z80 E3000                ; Set steps per mm
    M566 X1000 Y1000 Z1000 E500         ; Set maximum instantaneous speed changes (mm/min)
    M203 X600000 Y600000 Z600000 E450    ; Set maximum speeds (mm/min)
    M201 X3000 Y3000 Z3000 E500         ; Set accelerations (mm/s^2)
    M906 X1000 Y1000 Z1000 E1200 I60     ; Set motor currents (mA) and motor idle factor in per cent
    M84 S10                              ; Set idle timeout
    M572 D0 S0.05	;pressure advance (experimental)
    ; Axis Limits
    M208 Z0 S1                           ; Set minimum Z
    ; Endstops
    M574 X2 Y2 Z2 S1                     ; Set active high endstops
    ; Z-Probe
    M558 P4 H5 F120 T6000                ; Set Z probe type to switch and the dive height + speeds
    G31 P600 X0 Y0 Z14.825                ; Set Z probe trigger value, offset and trigger height (measured Z = 14.65)
    M557 R115 S20                        ; Define mesh grid
    ; Tools
    M563 P0 D0 H1 F2                     ; 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
    ; Heaters
    M305 P0 T100000 B4138 C0 R4700       ; Set thermistor + ADC parameters for heater 0
    M143 H0 S120                         ; Set temperature limit for heater 0 to 120C
    M305 P1 T100000 B4138 C0 R4700       ; Set thermistor + ADC parameters for heater 1
    M143 H1 S280                         ; Set temperature limit for heater 1 to 260C
    ; Fans
    M106 P2 S0 I0 F500		     ; Set fan 2 value, PWM signal inversion and frequency.
    M106 P1 S1 I0 F500 H1 T45            ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on
    ; Automatic saving after power loss is not enabled
    ; Custom settings are not configured
    ; MCU temperature correction
    M912 P0 S-3.2

  • Do you have the same problem with pressure advance disabled?


  • Seems better now. Wow, that was simple.

  • Moderator

    @Mentaluproar said in gap fill causes stepper to spasm:

    M566 X1000 Y1000 Z1000 E500

    Likely due to the low E jerk.

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