60mm Pulley (12mm rope)

thingiverse

This is a 60mm pulley designed for use with 12mm rope on sailboats. I rely heavily on these pulleys during my sailing activities, and they frequently fail without warning, so I decided to print one to see how long it would last. The design incorporates an M8 x 35mm through bolt, 22mm 608zz stainless bearings (skateboard bearings), and a 6mm wide jaw shackle. Stainless steel components were chosen for their exceptional durability on boats. While this pulley may not match the quality of a Harken block, it has proven capable of supporting my weight without issue. Initial tests revealed weaknesses in the wheel under extreme loads, which could cause it to split. However, I've successfully mitigated this issue by using nylon and surface treating the wheel with thin superglue. This design is intended for light use only. Print Settings: Printer: XYZ Davinci 1.0 Rafts: No Supports: No Resolution: 0.2 Infill: 30% Notes: Adequate cooling is necessary to prevent the wheel from sagging on its top lip. Post-Printing: The two cheeks and block are best bonded together using acetone welding. I sand the top of the block to remove any printing marks, then dip it in acetone and attach it to the cheek while ensuring proper alignment. I repeat this process for the other side and secure them with a bolt, allowing the bond to set for half an hour before sanding it smooth over the weld. The block responds well to sanding and an acetone wipe, resulting in a lovely finish that's a pleasure to hold. The wheel is designed to be slightly oversized, so I sand its faces on a flat surface, particularly the top, which may exhibit some roughness. Once the bearings are inserted, I fit the wheel into the block and rotate it while sanding the outside edge to remove any print imperfections. This results in a smooth fit within the block. 22mm bearings press into the wheel from either side using a vice and a piece of card for protection. I've also used plastic bearings temporarily until my stainless steel ones arrive, as they don't last long in use but are helpful for lining up components. Before and after sanding photos demonstrate the improvement in quality.