That’s pretty neat!
It looks like adding another stepper motor to spin it would be fairly easy, and I imagine manually adding gcode to do the 120 degree turns would also be simple - but what the ideal tool path would be for 4 axis milling? And how could you create it? And could Marlin handle it?
I guess you can turn your model in fusion 360 twice by 120 degrees and prepare 6 or more 3x job files. Then run them one by one
a more recent one using a hexagon which i thought makes more sense
I’m just gonna throw this out there… you can pick up a complete 4th axis kit using a nema 23 motor, external driver, 3 jaw style lathe chuck for just a few hundred. You’d need at least two spare pins for step/dir directions to the external driver (and knowledge of how to configure marlin for those) but you could add a 4th axis and not even double the cost of your mpcnc.
More info on the 4th axis?