Nema17 Compact Planetary Gearbox 5:1

Single-Stage Planetary Gearbox (5:1) for NEMA 17

This is the high-performance, compact, single-stage gearbox designed to fit standard NEMA 17 stepper motors, as seen in my recent testing video. It provides a clean 5:1 torque multiplication, allowing you to get significantly more rotational force from a cheap stepper motor. 

This design is version 3 - the final result of multiple iterations focused on smooth operation, durability, and standardizing hardware. It uses a 0.5mm module size, which I found to be the sweet spot for FDM printing with a standard 0.4mm nozzle. Can be used for example in a robotics chassis project as shown in the video below (at the very end)

[YT VIDEO]

Proven Performance (Torture Test)

I designed this gearbox to test the absolute limits of 3D-printed gears. Although this single stage only experiences 1/5 of the total force applied in my full 25:1 stack, it was crucial to making the entire system work.

• Design Iterations: It took three versions to perfect the tolerances and smooth operation.
• Material: Surprisingly strong! My test unit was printed entirely in PLA.
• Module: 0.5mm, optimized for FDM printing.

Hardware Required (Bill of Materials)

Beside the 3D printed parts, you will need the following standard hardware to assemble the gearbox. Please check your specific output shaft design to confirm bearing and screw counts.

• 1x NEMA 17 Stepper Motor
• Bearings: 6804 x1, 693 x3, 625 x1
• M3 screws