Wiring and extruding using an e3d toolchanger, without a Duex.



  • I've got an idea, that I'm sure isn't original, for printing with more than two filaments, using a Duet 2, without the Duex, and I want to not only show some of my working, but confirm that this is indeed possible, and more importantly sensible.

    The first part is to wire the E0 and E1 motors to a design derived from Prusa's multi-material extruder. One works as a selector, the other drives the selected Bowden tube.

    0_1538058779051_screenshot.973.jpg

    The second part is to wire each additional hot end after the second one using a 2a DC-DC SSR (or mosfet?) using the pins on the expansion header as a signal, and the thermistor pins as normal.

    0_1538058789978_1280px-DuetWifi_expansion.jpg

    Is there anything obvious that I am somehow not factoring in, that would make this impossible?


  • administrators

    That looks entirely feasible. You will need a mechanism to home the selector motor, such as an endstop switch or stall detection. You won't have enough fan outputs to control the tool fans individually.

    The heater outputs are low=on.



  • @dc42 said in Wiring and extruding using an e3d toolchanger, without a Duex.:

    That looks entirely feasible. You will need a mechanism to home the selector motor, such as an endstop switch or stall detection. You won't have enough fan outputs to control the tool fans individually.

    The heater outputs are low=on.

    Yeah; for the fans, I was actually contemplating a design to have one fan on the effector, and a fan each on the docks, to keep the changed tool as minimalist as possible. But I suppose I'd just have to run them all, or none at all.

    And good point on the endstop for the selector.

    Am I right that I understand low=on to mean low amps, ie, they are appropriate for a signal, but not for heating?


  • administrators

    @mortarart said in Wiring and extruding using an e3d toolchanger, without a Duex.:

    Am I right that I understand low=on to mean low amps, ie, they are appropriate for a signal, but not for heating?

    Noi, it means that they output a low voltage (logic low, close to 0V) when the heaters are supposed to be on, and a higher voltage (around 3.3V) when they are supposed to be off.



  • I suppose I could just use the programmable fan outputs to trigger SSRs.


 

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