Print in place Cycloid Gearbox, For NEMA 17

myminifactory

This is a compact Print-in-place gearbox specifically designed for a NEMA 17 stepper motor. It exploits the supportless printing freedom offered by SLS to achieve maximum compactness. The intention behind this design is to enable users to print it, remove it from the powder bed, and directly attach it to a nema motor as a single unit. This gearbox is part of an ongoing project that involves creating an SLS'ed Print-in-Place robot arm. While the arm may not be remarkably precise or inherently useful, it serves as an excellent "flex" print for SLS machines, effectively showcasing the mechanical capabilities of the technology. The model is fully parametric and was created using Fusion 360. Approximately sixteen points define the cycloid curve, which are then connected by a spline to approximate the actual cycloid surface. I would be happy to provide a tutorial on how to model it if there is sufficient interest. Cutouts in the side of the gearbox allow trapped powder to escape from the gear mates during printing. Initial testing indicates acceptable tolerances, but these can be adjusted as needed. Adding a lubricant such as "white lightning" after cleaning out the gear mates significantly improves performance. This design features several bearing surfaces that are less than ideal due to their necessity in achieving print-in-place functionality.