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Unload filament heating also the bed.  

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Unload filament heating also the bed.

After a print completed, and both the bed and extruder got cold, I selected "Unload filament" and picked PET. To my surprise, I saw the LED on the bed turn on, and the bed got heated too. 

Why does the bed need to be heated if only the extruder is needed for the unload?

Is this a bug, a feature or this is how it works?

Thank you, 


Posted : 27/07/2020 3:33 am
RE: Unload filament heating also the bed.
  • Hello Roy,

    This action  is design Intent, but the designers have given you tools to negate the issue. 

    I use palette2 S Pro with My Prusa, and the Palette 2 slicer (Canvas) Always leaves a short stub of filament sticking out of the extruder, so I added the line shown below to My Custom Gcode, End Gcode, and now the filament is always ejected at the end of the print with no extra heat cycles. 

    Palette end Gcode sample
    G1 E-100 F1000: Eject Filament Stub
    M106 S0 ; turn off cooling fan
    M104 S0 ; turn off extruder
    M140 S0 ; turn off bed
    G1 X0 Y200 ; part removal
    M84 ; disable motors
    M900 K0 ; reset linear advance to off by default

    NOTE, the command could probably go anywhere in the End Gcode, but I chose to put it before the extruder was turned off... 
    if you put the line, in red, in your end Gcode, the filament will always be unloaded for you. (NOTE2! this is a Mk3/3S thread, 
    If you had a Mini, or a Mk2 with MMUv1 you would need to include a longer unload distance to account for the Bowden length. 

    Or you could set a small Gcode on your SD Card that  Heats the extruder for you, ejects the filament and cools the extruder, 
    You could even add bleeps, to let you know when the filament is being ejected to save you having to monitor the LCD and press additional buttons. 


  • Or you could choose "Settings>Temperature>Nozzle" and then choose your temperature. 

    Or you could go to the Prusa Slicer Github page and re open the issues that have been raised by other people on this subject. 
    GitHub is where the Developers monitor issues. 

    regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 27/07/2020 12:40 pm