Run 2 separate mixing Hotends

What is the easiest way to get 2 diamond hotends to run with 5 extruder per hotend.
Exceeding the firmware limit of 6 extruder.
Is there a way to mirror the extruders if I have separate motor drivers for them
and never print with more than 6 extruder at once?
I'm not looking for in excact solution, just the easiest approach with existing firmware.


  • V1 firmware has no support for 2 mixing extruder at all so that becomes already difficult plus the limit to 6 extruders.
    V2 firmware has no extruder limit, but due to lack of owning a printer with such an extruder I did not write a module for mixing extruder. But due to the module nature it would then much easier to solve. 
    One other problem that might arise is that the gcode commands to configure it also assume only one extruder. But that needs to be solved for V2 anyway since it is possible then.

    But why would one need 2 mixing extruders if you can mix any color with one?
  • Since the diamond only mixes passivley, it's best to have as many individual colors as possible.
    Does V2 allow me to add 12 extruders and only mirror extruder 7-12 to 1-6, since I only print with one diamond at a time?
    Then depending on which diamond hotend to use, set enable signal of 1-6 to high and 7-12 to low. Steps and dir still get send to all 12 extruders.
    (some minimum extra hardware need to control the enable signals)
  • As said V2 has no mixing extruder module at the moment, so no it does not support it.

    At the moment you would need to heavily modify V1 to have extruder 17-32 use same mixing ratios but use other motors. For own mixing rations there is not enough memory in eeprom I think. So I think you need to make a switch based on extruder id which set to use. Something like that. Or you write the V2 module and can do pretty much what you like.  How good are your programming skills in C++?

    Which board has so many outputs. btw?

  • Ah okay, misunderstood the part about V2 not having a mixing module yet.
    My programming skills aren't good enough for a C++ implementation.
    This will probably be a G-code post processing script with M42 P.. S.. codes for now.
    Not sure if there will be enough pins on my ramps board, didn't check because changing to a board with more pins would be the easiest part I guess.
    Right know I'm running a 6 extruder hotend with a Ramps+CNCshield (4 extra drivers) and using the Aux-2 pins and sacrificing one endstop pin.

Sign In or Register to comment.