Looking to add pneumatic extrusion for bio-printing on duet wifi



  • hey guys, first post here, as i said in the title i am looking to add a pneumatic extrusion for bio printing materials which would include control for a 24v air pump a pressure transducers (analog out put for pressure) and
    a digital pressure regulator.
    ideally i would like to be able to control these using custom g-code commands.
    my background is primarily in ME but i have a background in python, can someone tell me if this is even possible or if i need a custom PCB that would be extremely helpful


  • administrators

    The air pump could be driven from a fan output if its startup current is low enough, or from a heater output with the addition of an external flyback diode otherwise. However, if you need to use pressure sensors and regulate the pressure, then you would need to interface them to the Duet and modify the firmware to handle them.

    Alternatively, you could use an Arduino or similar to handle the pressure regulation, and send it commands from the Duet.

    There are several GCode commands and parameters in RepRapFirmware that may be suitable for commanding the pressure:

    • M571 (set output on extrude)
    • M3 (spindle or laser control)
    • P parameter of the G1 command
    • S parameter of the G1 command if you switch the firmware into laser mode

    HTH David



  • which method do you think would be easier.. modifying the firmware (i would be very lost) or running commands through an Arduino


  • administrators

    @satchel17_ said in Looking to add pneumatic extrusion for bio-printing on duet wifi:

    which method do you think would be easier.. modifying the firmware (i would be very lost) or running commands through an Arduino

    Then I suggest you put the code to read the pressure sensor and regulate the pressure on an Arduino. A 3.3V Arduino will be easier to interface to the Duet than a 5V one.


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