Prusa Research MMU3 Manual Del Usuario página 103

PASO 29 Extruder-idler-mmu assembly (Part 1)
Toma la tuerca M3n y colócala en el Extruder-idler-mmu2s.
Use the screw pulling technique.
Insert the Bondtech gear into the idler as shown in the picture. Make sure the
geared part of the Bondtech is on the side of the plastic part with the cutout.
Slide the shaft in through the idler and the Bondtech gear. Use reasonable force to
prevent breaking the plastic part.
PASO 30 Extruder-idler-mmu assembly (Part 2)
Using the 2.5mm Allen key, push the shaft in so that it is inserted evenly on both
sides.
Ensure the Bondtech gear is able to rotate freely.
9B. Mod extrusor MK3S+ (KIT)
Ensamblaje Original Prusa MMU3 103