MK4S MMU3 to CORE ONE MMU3

The mount is attached to the prepared holes on the back of the printer using 2 M3 screws and 2 hex nuts, which can be taken from the spare parts bag. The PTFE tube passthrough is mounted to the top lid of the printer. You will need to drill four 3 mm holes, then install the passthrough mount, and finally drill a 4 mm hole through the central opening for the PTFE tube.

The new MMU mount is attached in the same way as the original MMU mounts for the MK4S.

IMPORTANT! The mounts are mirrored, so it’s necessary to distinguish between the right and left one (this is marked directly on the model).

The MMU is angled at 30 degrees to ensure smooth filament flow. In my case, I used a Y splitter (from this solution) inside the printer so I could still print without the MMU by feeding filament from a side spool holder.

With this setup, you need to go to Settings → Hardware Settings → MMU and set the PTFE length to approximately 880 mm.

The large distance between the MMU and the nozzle causes the filament to unload outside the buffer. I solved this by using a buffer cover:

https://www.printables.com/model/1347543-mmu3-cartridge-cover

Keep the PTFE tube between the MMU and the extruder as short as possible, but not too short — it should still allow the filament to pass through smoothly. I positioned the passthrough on the top panel exactly in the middle and as far to the right as possible. The passthrough is secured with four M3x10 screws and M3ns square nuts from the spare parts bag.

So far, I have completed 6 multi-color prints using this solution. I encountered filament jams during the first two, but after implementing the above adjustments, this is now my final setup, which works reliably. However, keep in mind that this is a custom solution, and you’ll need to spend some time fine-tuning the settings to get everything running smoothly.