SOLVED Hemera Under Extrusion Despite Tuning



  • Hello All, I am having an issue with major under extrusion with my Hemera on a Duet 3 6HC. I have done the esteps calibration for the extruder and verified it is correct, but I am still seeing heavy under extrusion when printing. I've made sure my thermistor values are correct, done a PID tune, and played around with the temperature a bit to no avail. (195C-200C, which has worked with this specific PLA before.) Any help would be greatly appreciated.

    Here are some photos:
    rear of benchy

    Here is my current config.g:
    ; Configuration file for Duet 3 (firmware version 3)
    ; executed by the firmware on start-up
    ;
    ; generated by RepRapFirmware Configuration Tool v3.2.3 on Wed Feb 17 2021 16:50:37 GMT-0700 (Mountain Standard Time)

    ; General preferences
    G90 ; send absolute coordinates...
    M83 ; ...but relative extruder moves
    M550 P"CR 10" ; set printer name

    ; Network
    M552 P192.168.0.99 S1 ; enable network and set IP address
    M553 P255.255.255.0 ; set netmask
    M554 P192.168.0.1 ; set gateway
    M586 P0 S1 ; enable HTTP
    M586 P1 S1 ; enable FTP
    M586 P2 S0 ; disable Telnet

    ; Drives
    M569 P0.0 S0 ; physical drive 0.0 goes backwards
    M569 P0.1 S0 ; physical drive 0.1 goes backwards
    M569 P0.2 S0 ; physical drive 0.2 goes backwards
    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 X80.00 Y80.00 Z400.00 E398.00 ; set steps per mm
    M566 X900.00 Y900.00 Z60.00 E120.00 ; set maximum instantaneous speed changes (mm/min)
    M203 X6000.00 Y6000.00 Z180.00 E1200.00 ; set maximum speeds (mm/min)
    M201 X500.00 Y500.00 Z20.00 E250.00 ; set accelerations (mm/s^2)
    M906 X800 Y800 Z800 E1300 I30 ; set motor currents (mA) and motor idle factor in per cent
    M84 S30 ; Set idle timeout

    ; Axis Limits
    M208 X0 Y-18 Z-8.70 S1 ; set axis minima
    M208 X285 Y292 Z400 S0 ; set axis maxima

    ; Endstops
    M574 X1 S1 P"io0.in" ; configure active-high endstop for low end on X via pin io0.in
    M574 Y1 S1 P"io1.in" ; configure active-high endstop for low end on Y via pin io1.in
    M574 Z1 S1 P"io2.in" ; configure active-high endstop for low end on Z via pin io2.in

    ; Z-Probe
    M558 P0 H5 F120 T6000 ; disable Z probe but set dive height, probe speed and travel speed
    M557 X15:215 Y-3:195 S20 ; define mesh grid

    ; Heaters
    M308 S0 P"temp0" Y"thermistor" T100000 B3950 ; configure sensor 0 as thermistor on pin temp0
    M950 H0 C"out1" T0 ; create bed heater output on out1 and map it to sensor 0
    M307 H0 B0 S1.00 ; disable bang-bang mode for the bed heater and set PWM limit
    M140 H0 ; map heated bed to heater 0
    M143 H0 S150 ; set temperature limit for heater 0 to 150C
    M308 S1 P"temp1" Y"thermistor" T100000 B4267 ; configure sensor 1 as thermistor on pin temp1
    M950 H1 C"out2" T1 ; create nozzle heater output on out2 and map it to sensor 1
    M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit
    M143 H1 S305 ; set temperature limit for heater 1 to 305C

    ; Fans
    M950 F0 C"out6" Q500 ; create fan 0 on pin out6 and set its frequency
    M106 P0 S0 H-1 ; set fan 0 value. Thermostatic control is turned off
    M950 F1 C"out7" Q20 ; create fan 1 on pin out7 and set its frequency
    M106 P1 S1 H1 T45 ; set fan 1 value. Thermostatic control is turned on

    ; Tools
    M563 P0 D0 H1 F0 ; 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

    ; Custom settings are not defined

    ; Miscellaneous
    M501 ; load saved parameters from non-volatile memory
    M911 S10 R11 P"M913 X0 Y0 G91 M83 G1 Z3 E-5 F1000" ; set voltage thresholds and actions to run on power loss



  • @linuxinstalled
    did it work before?
    Did you change anything in the slicer settings?
    Did you tune in the spring of the filament-pressure bearing? (I once forgot to retighten it after filament-change, so it's on my list of checkpoints)

    Also try to extrude by hand. It should not be too hard to push filament through. Maybe you have to clean the filament path and check the teflon liners.



  • @linuxinstalled double check what diameter is set in your slicer.

    Are you using volumetric extrusion?



  • @linuxinstalled said in Hemera Under Extrusion Despite Tuning:

    M566 X900.00 Y900.00 Z60.00 E120.00 ; set maximum instantaneous speed changes (mm/min)

    My settings for Hemera on this line are:
    M566 X900.00 Y900.00 Z24.00:24.00 E1200.00

    also acceleration on mine is 500 instead of 250:
    M201 X1500.00 Y1500.00 Z200.00:200.00 E500.00
    maybe this will help?



  • an easy test to rule out the slicer is try a different slicer.

    prusaslicer is easy to setup and test.



  • Ladies and Gentlemen, we got 'em.

    For reference of those who see this post in the future, this was a conversion of a CR 10 to a Duet controller with a new hemera. None of these components had been tested before, so it was all new.

    In order to account for these changes, I created a new profile for the printer in Cura. My mistake was not checking the "extruder" portion of the configuration.

    It was set to a filament diameter of 2.85mm instead of 1.75mm. This explains why I could somewhat fix the issue when I set my extrusion factor to 150%.

    After making the change, and reslicing, the first few benchy layers appear to have the issue fixed.

    Thank you to all of you who posted with ideas for help. Luckily it appears this solution was simple.


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