Cycloidal Nema Generator (Bearing-less)

This project allows you to generate a fully 3D-printable cycloidal gearbox, designed to mount directly onto NEMA stepper motors (11, 17, 23).

The design is bearing-less. It’s not optimized for low friction but rather designed to be the simplest and fastest way to test a cycloidal gearbox, drastically reducing the number of required non-printable components.

Features

• Fully Parametric: Customizable via OpenSCAD to fit different NEMA sizes and reduction ratios.
• Bearing-less Design: No expensive bearings required, relies on printed surfaces.
• High Torque: Cycloidal drives offer high torque density and zero/low backlash.
• Compact: Mounts directly to the motor face.

Assembly Instructions

The assembly order onto the motor is as follows (from bottom to top):

1. Stator (Housing): Place the stator ring onto the motor and secure it using 4 screws.
2. First Cycloidal Disc: Drop the first rotor disc into the stator.
3. Input Shaft: Insert the eccentric shaft into the center, aligning it with the motor shaft and the first rotor.
4. Second Cycloidal Disc: Place the second rotor disc onto the upper cam of the shaft (180° offset from the first).
5. Output Shaft: Insert the output disc on top, ensuring its pins slot into the rotor holes.
6. Housing Cap: Close the assembly with the top cap to secure the output shaft.

Required Hardware

• NEMA Stepper Motor (Size 11, 17, or 23)
• 4x M3 Screws (Length depends on your stator height, usually 30-40mm)
• Grease: Essential for smooth operation. White lithium grease or silicone grease works best.

Printing Tips

• PETG or Nylon are recommended for the moving parts (Rotors/Shafts) for better wear resistance and lower friction.
• PLA can be used for the Stator housing.
• Walls: Use at least 3-4 walls for strength.
• Infill: 30-40% Gyroid or similar.
• Tolerance: If the gears are too tight, try increasing the tolerance parameter in the Customizer (default 0.2mm).

Created by Redicov.

Website: rediscov.it
YouTube: @rediscov