Diamond hotend with single extruder motor Today I started to google the idea of multimaterial printing. I checked out prusa multimaterial upgrade and while it looks nice, it is expensive and will not probably work with my non-prusa printer.

I discovered there is Diamond hotend, which allows for 3 (or even more) colors at the same time. But everywhere I checked, one extruder motor was used for each color. Since my MKS Gen L motor connections are already all used, I was thinking if it would be possible to handle all of the filaments with single extruder motor.

Basically the motor would have long shaft which will cover all filaments, and I would add some servo that would push a pulley against the selected filament.

I think I would slice it as a multiple hotend setup and then postprocess the gcode in a way, that when tool is changed I would add custom command that would push the pulley against appropriate filament.

I would either need a servo for each of the filemants, or maybe with some clever mechanics one servo in different positions could do all of them.

I am just curious if you think this would be possible to do, since I did not find anyone discussing this idea. Probably because it will require adding custom commands to the firmware.
You might save yourself a lot of engineering by copying the Prusa MMU2.  Here is a github project for someone doing exactly that:  https://github.com/cskozlowski/mmu2

If you look on Prusa's web site, you can find printable parts for the MMU2.