MMU2 Spool guide upgrade to use 2 filament roller trays as a 3 spool roller
I haven't seen this used or posted before, but I also don't exactly know what to call it or how to search for similar designs. Print 4 of these guides and use 4x 608 bearings. Then you add a third rolling axis in-between the two trays. See the photos, anyone who uses the Prusa roller trays will probably be able to use this. All three spools still spin independently.