Multi-Stage Planetary Gearbox (3:1 per stage)

This is a modular, multi-stage planetary gearbox design, where each stage provides a 3:1 gear reduction. You can stack as many stages as you need to achieve your desired total gear ratio.

Overview

This design is built for scalability. Each segment is designed to nest into the previous one, allowing for custom gear ratios (e.g., 3:1, 9:1, 27:1, 81:1, etc.).

Hardware Required

To assemble the gearbox, you will need the following components:

* Center Shaft: 5mm brass rod. You will need to cut this to length based on the total number of stages you choose to assemble.

* Fasteners: 4x 3mm bolts and nuts (length will depend on your stage count; typically 10mm-12mm per stage).

* Motor Mounting: The files include two distinct motor mounts and two corresponding input gear options to accommodate different motor shaft configurations:

* NEMA 17 Mount: For standard stepper motor installations.

* Circular DC Motor Mount: For standard circular-body DC motor installations.

Printing Instructions

* Material: PLA, PETG, or ABS/ASA are all suitable. I recommend PETG for better durability in the gear teeth.

* Supports: Minimal to no supports needed if printed in the correct orientation (gears flat on the bed).

* Infill: 20-40% is sufficient for the housing. For the gears, 40-50% or higher is recommended for increased strength under load.

* Tolerances: The gears are designed with a tight tolerance. If you have trouble with the fit, try slightly adjusting your horizontal expansion settings in your slicer.

Assembly Notes

1. Preparation: Clean up any strings or elephant-footing on the printed parts.

2. Stacking: Slide the gears onto the 5mm brass shaft as you assemble each housing stage.

3. Bolting: Use the 4x 3mm bolts to secure the housing stages together. Ensure they are tightened evenly to prevent binding.

4. Motor Attachment: Mount your chosen motor (NEMA 17 or DC) to the final stage using the appropriate mount and matching gear for your motor's shaft.

Note: This design is shared for personal use and experimentation. Please feel free to remix and modify to fit your specific needs.