Herringbone gear rack and pinion

cults3d

This is a double helical gear rack and pinion, reimagined from a single helical rack and pinion by janssen86. Doubling up the helical teeth eliminates the axial thrust of a single helical gear while keeping it centered. I ran a test print before incorporating this into a larger project, but I also discovered that both I and my kids enjoyed using it as a fidget toy! The way the pinion stays in sync with the gear is surprisingly satisfying. No supports were needed. I printed at 0.20mm resolution with a 0.40mm nozzle. Note that in this design (not the one I tested), the pinion prints upside-down relative to the rack. This was intentional, as it helps prevent the bottom side from getting crushed, thereby preserving symmetry. The crushing issue caused my test print not to align properly. I plan on running another test print at some point.