High power heater cartrdige PID settings?



  • Hello all,

    I'm having a little bit of difficulty getting the best PID settings for my current printer setup.

    Setup:
    Duet
    24V
    DyzeEnd Pro with a 60W heater cartridge
    PT100
    Water cooled

    I've run Autotune to 450deg C at 0.75PWM and the following figures were presented to me with a warning that the unit can reach 1060 deg C.

    GAIN: 1035
    Temp Constant: 378.5
    Dead Time: 3.6

    When I bench test these they worked well, I also setup start gcode for my less power hungry filaments which simply sets the PWM to 0.5. All this worked really well.

    However when I put these figures into my printers config I keep getting heating up errors telling me the unit is not heating up fast enough.

    Now I have deleted the config.overide from both machine as too be honest I don't know why it is there.

    • Could it be that somwhere else there is more failsafe PID settings which I'm missing?

    • Has anyone else experienced this? If so what can be done to fix it?

    Any help would be greatly appreciated.

    Cheers,

    Andre


  • Moderator

    If you're changing the PWM factor after the tuning that could explain it. You could run PID tuning at 75% and at 50% and then load those tuned values as needed.

    I've run Autotune to 450deg C at 0.75PWM and the following figures were presented to me with a warning that the unit can reach 1060 deg C.

    That 1060c figure is based on 75% power, and in a failure situation you would be getting 100% power, so that 1060c is lower than what you might actually get. 60w will slag your hotend in a failed on state. So definitely have some precautions in place.



  • Thank you very much for the reply.

    I'll try that.

    With regards to the config.override in the systems folder do you know what that is for?



  • @C6D see https://duet3d.dozuki.com/Wiki/Gcode#Section_M501_Read_stored_parameters and also M500 to store them. Emulates marlin and repeteirs eeprom function, sort of.


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