Improved MMU2 Buffer for Prusa Enclosure V2

prusaprinters

<p>The first version of this MMU2 buffer ( <a href="https://www.thingiverse.com/thing:4138220">https://www.thingiverse.com/thing:4138220</a> ) 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:</p> <p>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.</p> <p>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.</p> <p>Bill of Materials</p> <p>Plexiglas<br/> <a href="https://www.tapplastics.com/">https://www.tapplastics.com/</a><br/> 6 x Extruded Acrylic Clear 2.5 mm Thick, 125 mm Wide, 350 mm Long</p> <p>Fittings<br/> 10X Fitting PC4-M10<br/> https://www.amazon.com/gp/product/B07V3G71HK/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&amp;psc=1&amp;tag=tv-auto-20</p> <p>Bearings<br/> <a href="https://www.vxb.com">https://www.vxb.com</a><br/> 5X 10 X 19 X 5 bearing</p> <p>Screw,Nuts<br/> 15X Hex Nut M3<br/> 10X Sq Nut M3<br/> 25X SHCS M3 X 8<br/> 4X FHCS M3 X 10<br/> 4X BHCS M3 X 8<br/> 7x SHCS M3 x 6</p> <p>PTFE Tube<br/> <a href="https://fluorostore.com">https://fluorostore.com</a><br/> I'm using 3/32" ID X 5/32" OD with good performance</p> <p>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.</p> <p>As always, STEP file included if you want to tinker.</p> <p>The original design from GVader:<br/> <a href="https://www.thingiverse.com/thing:3895861">https://www.thingiverse.com/thing:3895861</a></p> <h3>Print instructions</h3><h3>Category: 3D Printer Accessories Print Settings</h3> <p><strong>Printer Brand:</strong> Prusa</p> <p><strong>Printer:</strong> MMU2s</p> <p><strong>Rafts:</strong> No</p> <p><strong>Supports:</strong> Yes</p> <p><strong>Resolution:</strong> 0.15</p> <p><strong>Filament:</strong> Prusament PETG<br/> <strong>Notes:</strong></p> <p>top and bottom plates requires support, the rest can be printed without</p>