Rotating color mixing nozzle - 3D Printer hotend

Описание: Rotating mixing nozzle to print with different colors.
The color change is only done by rotating the nozzle to expose different colors on the outer perimeter.
Usually mixing nozzles vary the extrusion ratio to change the color. This comes with the disadvantage of needing to purge the nozzle first.
And even then you still end up with a toothpaste effect which will cause the color to shift based on the direction of the printing path.
Rotating the nozzle will let you counteract this color shift + color change is almost instant.
Extruding all filaments at the same ratio is also good for a consistent (and higher) flow rate + no idling filaments that get cooked in the hotend.


Biggest challenge with a rotating nozzle is twisting the filament inputs.
Bowden tubes can be twisted some, so you end up having 2-3 full rotations of freedom with the current setup.
Which is good enough considering that you can 'unwind' the nozzle on travel moves. (could do so on printing moves as well, but you'll end up with a small extrusion artefacts from pausing there)
If you really wanted infinite rotation you could rotate the filament spools and put extruder+heater wires on a slipring.
But rotating whole filament spools over your hotend isn't the most elegant solution. But I can't think of a simpler way.


Printer runs Marlin, configured with a 4th A-axis for nozzle rotation

Mapping of texture to nozzle angle is done via python script inside of Blender.
Leveraging lots of nozzleboss addon code here, which already has color to gcode logic built-in.