Dual switching extruder

  • I just received my dual switching extruder from Makertech I purchased on Kickstarter. It uses a servo to switch from one extruder to the other. I know I can make it work with Marlin but no idea how to take the Markin instructions and make work on my Duet Maestro. I have finally gotten away from Marlin and upgraded all 4 of my printers to Duet Maestros and love them. I do not want to go back to Marlin in one just to use this new setup. I am confident I have everything set up on the extruders and hot ends but not sure about the tool change/servo code. I know the offset numbers for the hot ends and their angles for servo but not sure how to set up my M280 code and tool change. I assume once this is correct just a matter of slicer settings which I use S3d. Any help would be appreciated as only been using Maestro boards for a couple months now and still learning the code.

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    First you need to connect the servo to the Maestro. If you are not using a BLTouch then you can use pins 11, 12, 13 of the 13-pin expansion connector (they are Servo, +5V and Ground respectively).

    Next, find the correct M280 commands to move the servo to the correct position. Using the connections above, the command is M280 P64 Snnn where nnn is the required servo angle. Make sure that the angles you use are within range of the servo, because if they are not then the servo motor will run continuously, and eventually burn out.

    Now you can put those M280 commands in your tpre0.g and tpre1.g tool change files so that they are run automatically when you change tool. See https://duet3d.dozuki.com/Wiki/ConfiguringRepRapFirmwareCartesianPrinter#Section_Tool_change_files. Note, there is a bug in firmware 2.02 whereby if no tool is selected and a M109 command is received, a tool is selected implicitly but the tool change files are not run. This will be fixed in firmware 2.02. Meanwhile, you can work around it by putting T0 in your start.g file.

  • Thank you I was using a BlTouch but new setup uses an inductive probe so I will wire servo to where the BLTouch pin control was wired. I have all the mechanics done and will finish the wiring and programming this week. I hope this finally gives me a dual extrusion option as tried almost everything else.

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