About this project
A parametric, single-stage spur-gear gearbox for NEMA 17 motors, designed around printable parts and accessible assembly. The baseline uses a 20-tooth pinion and 60-tooth output gear for a 3:1 reduction; the requested ratio is adjustable from 2:1 to 5:1, with tooth count, shaft spacing, and housing size driven by the gear geometry.
Selectable motor configurations and custom dimensions support round or D-shaped shafts with an adjustable flat offset. The gears sit close to the housing floor, with their split clamp hubs facing upward. Features include press-fit output-bearing seats, an 8 mm output shaft, a removable top cover, recessed screw heads and captured nuts, integral housing contact rings, and separate printable washers above and below the output gear assembly.
Blended hub roots, small edge rounds and chamfers, adjustable clamp-ear thickness, and a 45° motor-locator roof address assembly, stress transitions, and printability. Grouped parameters and separate Enclosure, Gears, and Hardware groups make the design easier to configure and inspect.
Prototype status: Bearing fits, clamp fastener clearances, axial retention, washer capture, and operating loads still require validation before fabrication or use.
Designing a Parametric NEMA 17 Gearbox — article draft. The companion article explains the design choices and development of this project; the draft currently requires author access.