This is a guitar string winder. It makes changing strings a much quicker task.

Just print it out, and it snaps together, no tools or screws required. The pin fits through the crank and into the handle. It's s friction fit of the pin into the handle, but the crank should turn freely, but be held captive by the pin.

The canonical openscad file for this design is on github: http://github.com/smcameron/guitar_string_winder