Today I used my 3d printer for something useful.
I have an (old and expensive to repair) automatic trash can opener, and in a fit of anger I slammed down the lid and heard something break.. Opening it up revealed a plastic gear has snapped in half in the gearbox mechanism that opens and closes the lid.
I tried epxoying it and supergluing it, and both fixes lasted less than a day. I then tried to figure out how I might order a replacement part. No luck.
I finally decided to try to use my 3d printer and print a replacement. I used OpenSCAD, which is magic, and an awesome library for it called involute_gears.
After a few experiments to get the fit exactly right, it seems to be working great. This is definitely the future of repairs.
