Higher-ratio evoloid planetary gear 33:1

thingiverse

By stretching the rules just a little we can obtain still higher ratios. Violating the soft *R=S+2P* constraint allows us to use evenly spaced planet gears with tooth counts which wouldn't normally mesh with a conventional ring gear. We can also squeeze in a few extra teeth in the ring gear for good measure. Note that the single toothed sun gear does not offer much in the way of stabilization of the planet gears hence this arrangement would require a carrier in practice. Print in place at 0.2mm layer height (for layer jumps and progressive bridging), also optimized for 0.4mm nozzle. Separate carrier using a sharp edge after printing. I scaled it up for printing to get enough meat on the center gear which is quite thin relative to everything else. I used 6 perimeters to add strength to the gears but also to allow bridging of the top carrier brace (see screenshot). After printing use a razor blade or sharpened spatula to go around the edges to separate the carrier top and bottom plates. I have also added some holes to grab with needle nosed pliers to help break the seal and get the gears turning. Normally these print in place planetary gears can be driven by the sun gear to free the rest up, but we are quite limited by how much torque we can apply to this fragile gear. If you are having difficulty with clearance try adjusting Horizontal Expansion in your slicer settings or recompile with a different *tol* value (0.3mm default).