I drilled 5 holes in the back of the cabinet to feed the teflon tubes from underneath and up to the MMU3. I spliced 2 and 2 tubes to get them long enough (several splicers can be found online).

To avoid the filament unspooling too much and possibly derail, I made one “derail preventer” of 1.5mm stainless welding wire.

Any material and settings will do but probably wise to avoid PLA due to long time stability.

Very little supports needed but use supports on build plate only, infill 15% seems ok.

This version have slightly modified holes for derailing preventer so that it can be fixed in front (easier access than the similar brake on rear side in original version). Having 10 ish filament loops hanging loose doesn't matter as long as you don't loose the end…

Version #2 (this one) allows for the filament spool to slide under the top so not protruding into the room and it is therefore also possible to close the cabinet and put in a bag of silica-gel inside to make the whole cabinet function as a dry storage while printing.

Redesigned axle which fits 2x 6082RS roller bearings for less friction even thou I never have experienced problems with the non-bearing axle on my Prusa MK4S. The ø20 axles are best for filament spools with no real hub like cardboard spools, ø50 for all others. If you have an old skateboard, you may find 6082RS bearings in the wheels…