Thumb Roller Hook for Dial Caliper

thingiverse

The replacement part is a thumb roller hook for a dial caliper that had broken, crafted via injection molding using polypropylene. To create the mold, aluminum was CNC milled following a design compatible with a 1/16 end mill. A Dremel carbide grout removal bit was used in the bottom half mold due to insufficient length of standard 1/16 end mills, while a 1/16 ball end mill enhanced the top side aesthetics. The aluminum molds' model files were provided; however, they did not include gates for plastic injection, which were manually carved post-molding. Although an alternative part was found online for approximately $8, I opted to DIY given my caliper's cost of about $15. Further details on the injection molding process can be found at scorchworks.com/Injection_molding/injection_molding.html.