Improved MMU2 Buffer for Prusa Enclosure V2

thingiverse

The first version of this MMU2 buffer ( https://www.thingiverse.com/thing:4138220 ) was a significant improvement over Prusa's stock version, loading/unloading and printing are a lot smoother. I had a 5 days print , with 2400 layers and 2200 filament changes with no MMU failures. But I also had a few under-extruded layers and I've narrow it down to the following root causes and fixes: 1) the 2.5mm Plexiglas on the outer sides can flex. The filament is quite stiff , can squeeze out and ruin your day. Solution: thick printed top and bottom plates, with profiles to hold all Plexiglas dividers in place. 2) there is still some unnecessary friction in the system , the filament can rub against the metal end of the PC4 M6 fittings.Solution: change to PC4 M10 fittings , where the PTFE tube goes through so no metal touches the filament. Bill of Materials Plexiglas https://www.tapplastics.com/ 6 x Extruded Acrylic Clear 2.5 mm Thick, 125 mm Wide, 350 mm Long Fittings 10X Fitting PC4-M10 https://www.amazon.com/gp/product/B07V3G71HK/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 Bearings https://www.vxb.com/ 5X 10 X 19 X 5 bearing Screw,Nuts 15X Hex Nut M3 10X Sq Nut M3 25X SHCS M3 X 8 4X FHCS M3 X 10 4X BHCS M3 X 8 7x SHCS M3 x 6 PTFE Tube https://fluorostore.com/ I'm using 3/32" ID X 5/32" OD with good performance So far I've printed a 30 hour Santa , 1010 layers and around 900 filament changes. Perfect print , no MMU or extrusion errors with the new buffer. A 5 days Nefertiti job , with 2400 layers and 2200 filament changes is ongoing. As always, STEP file included if you want to tinker.