Tractor

pinshape

Small toy tractor with a rubber engine :D All you need is to print and combine with some bearing (22 mm outer diameter, 8mm inner, 7mm height) and a rubber band. Crop the band in half after assembly to prevent it from staining. After that, just spin the handle for a few times and release it on the surface. It's best to print it with 0.1mm layer thickness or so, with 1mm walls being an ideal option. You can check these videos to see how it works: Video 1 and Video 2