Planetary Gearbox

thingiverse

A compact and reliable 4:1 planetary gearbox. This was both a test to determine the smallest printable component and a tooth profile that would consistently print on my machine without issues. The result may be useful for someone looking for a small and effective gearbox. Printed directly on my Up! mini without support. The planets work best when reamed out to 4.5mm, which can easily be done with a standard Jobber drill bit. Some sanding and filing will help smooth the teeth and bearing surfaces. Both input bearings and output bearings are standard 608Z skate bearings. Both input and output shafts have a 3mm hole for accepting an M3 screw. A 10x5x4 bearing can be used to support the input shaft in the output, as shown. For optimal performance, pack the unit with your preferred grease or oil, such as all-purpose EP2. The original design was a multiplication gearbox for a sunsky brushless quadcopter motor. Without lubrication, friction is high and at 50,000 RPM output it can become stuck together. However, it is still usable as a reduction box when the input speed is less than 20,000 RPM.