We were tasked with making some stilt characters for a parade with a toy theme. One idea that we pitched was a giant living wind-up-doll. I made the key and the housing for the motor and the harness.
This project is a rare one that takes a battery and uses a motor but doesn’t involve an arduino or other microcontroller. I modelled and 3d printed the housing for the electronics and the motor, sewed the straps, and used some materials I scrounged up in the shop to make the key itself.
Apparently I was in too big a rush making this to bother taking any pictures along the way, but here’s an image of the gear motor I used along with an early prototype for the mechanism. Because the key doesn’t weigh much and doesn’t turn fast I didn’t use any sort of bearing but just kept the key aligned by driving the inner of two nesting cylinders.
