Adding two custom extruders to reprap firmware and DWC

  • I'm building a multi extruder machine with tool switching. I successfully set up a duet wifi with a duex5 expansion board but I would like at least one or two more extruders. I know from reading that it is possible to hook up two external stepper drivers to the CONN_LCD pins on the duet 2 wifi and have figured out the hardware wiring from a previous forum posting. The only issue I have now is how to add them in the reprap firmware. I'm unable to add any more additional extruders through the configurator web tool. I tried simply manually changing the config.g file to two extra defined drives and that created a visual change in the DWC of adding two extra selectable drives in the Tools section of settings which I could click on. However whenever I try to create tool I get an error message that says "bad drive selection". Is there a hard-set limit to how many extruder drivers can be configured in the reprap firmware and if so is there any way around this? Does anyone have experience creating their own custom firmware?

  • Moderator

    @usescoasters See this page:

    You may be able to add two extra steppers on CONN_LCD (they map to drives 10 and 11, and are supported in firmware), but do you have spare connections for temperature control and heaters?

    Please post your config.g, and response to M115 so we know what firmware version you are on.


  • I do have enough open pins left on the duex5 board to actually connect the heating elements and temperature sensors of the extra nozzles themselves. My tool heads are as follows: 1) single nozzle stock extruder, 2) dual nozzle E3D chimera hotend, 3) M3D quadfusion mixing head -basically one nozzle with four motors independently pushing filament in. That adds a total of 4 required heating elements and temperature sensors. With the duet wifi and duex5 board combined I have more than enough thermistor and heater connections left over to fit two more extruder nozzles. As I understand it, it is possible to add two more to the duet with external stepper drivers. I just don't know how to configure the firmware tool.
    Here's my altered config.g fileconfig.g

  • Moderator

    @usescoasters firmware version? Send M115, post response.


  • administrators

    When you run M584 without parameters, what does it report?

    When you send M98 P"config.g" are there any error messages?

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