One of the many art tools I have of my dad’s this Boston Model 18 electric pencil sharpener. It quit working at the start of the summer, so I dissected to see what the problem was. The plastic gear seemed to have lost some of its teeth, and as I looked for schematics so that I could draw the gear in Illustrator then cut it with a laser cutter- I found someone who was already tooling gears for just this purpose. It was pretty easy to install, and now it’s up and running again.