Core One Nextruder Main Plate MMU

Sometimes, my printer (Core One) fails on unloading:

• The filament wraps around the extruder wheel, when the extruder retracts the filament.

• The problem occurs on unloading and at material change.

• My possible solution is to guide the filament at the inlet on the main plate as much as possible (red box). 

• Around 2mm of additional guide distance (original part 15mm, this part around 13mm)

• The diameter of the inlet is smaller than the original (2.2mm vs. 2.6mm).

• the main dimensions are from the original MJF part from the mmu upgrade kit. I didn't know if the original model is online. Some contours are simpler, because first i wanted to mill it from aluminium.

• printed in PETG CF for temperature and wear resistance.

• Tested on a Core one with V6 nozzle adapter.

Additional, i'm running with 5 cooling cycles and addtional cutting of the filament at the end of the print M706 Px (P= Number of Tool)

[Additional Version V2]: Added a version with some modications:

• Bigger mounting holes to push the plate against the extruder wheel.

• Additional guide, better print with 0,2mm nozzle.

• Latch for testing some future ideas.

[Importand Information]

At some printers, you have to change the filament parking position, especially if you hear a grinding noise just before the Filament is pulled back by the mmu3. The reason of the noise and the jamming is basically a to big retraction just before toolchange. If the distance is to high, the  teeth of the nextruder gear grab the filament tip and causing the jam.

V1:

V2: