1:246 Gearbox (Q44337)

Have you ever wanted to turn a CD-ROM motor into a winch? I decided to see how much gear reduction could be fit into a small space, so I came up with this differential planetary arrangement. This is a well-known design, but now you can use the parameterized OpenSCAD version to customize this to your needs and include it in your mechanical designs. The version shown here is less than 60mm in diameter and 13mm thick, but achieves a 1:246 gear reduction, all with teeth printed on a TOM. The input is the small shaft to the sun gear, the output is the smaller ring gear, and the larger ring gear is to be held fixed. If you stacked two of these units you would have a ratio of 1:60516!