Improved Prusa Mk3 Y belt holder - stock compatible

thingiverse

I modified the Y belt holder by MCPJ to ensure that holes print properly without supports by utilizing two layers below the unsupported holes with bridging lines. Additionally, I rounded off some chamfers for faster printing and removed unnecessary bottom edge chamfers. Note: Update 2 features a revised version that maintains better alignment of the Y belt (previous version had a slight offset). I will attempt to capture an image showing the belt path within the next couple of days. This design is compatible with both older belts supplied by Prusa and the Gates belts they started shipping later, which are superior but tend to slip in the stock Y belt holder. It works with either the standard idler or the Y belt tensioner designed by MattyVee (https://www.thingiverse.com/thing:2786671 - a great design that caused the Y belt to slip in the original holder). To install, you will need two M3x12mm screws and two M3 nuts (Nylock preferred) in addition to the M3 bolts used for the original belt holder. You can use the original belt length, but it may be slightly too tight. To accommodate this, loosen the motor mount and idler/tensioner before installation (install onto the bed first). If using a tensioner, ensure that it is set at its loosest before installing. Fold over a short section of the end of the belt, slide an M3 bolt through the loop, forming a loop around the bolt with several teeth interlocked where the belt folds back on itself. Then, slide the bolt into the hole and tighten until the bolt grips the nylock nut and the bolt head holds onto the belt (without squishing it). Repeat this process for the other end, then re-tighten the motor mount and idler/tensioner. If using a tensioner, adjust and tighten it. I recommend printing in PETG or a better material to withstand heat from the bed. ABS, PC, Nylon, and other materials should work fine, but avoid brittle ones like PCmax. Since PETG has some inherent flex and must endure stress, I suggest printing this design solidly (I printed with 4 perims, 50% gyroid, at 0.2mm layer height).