Show HN: I'm a 15 Year Old Wannabe Engineer, This Is a Cycloidal Gearbox I Built

This is my cycloidal gearbox I built, and the python script I created to generate it! This gearbox was a handcranked gearbox specifically meant to test the validity of the python cycloidal generator. It had a gear ratio of 1:9. This design was a micro cycloidal gearbox with a ratio of 1:9, meant to only take up the same footprint as a NEMA 17. Due to the tight tolerances needed for a small cycloidal drive and the lack of precision offered by 3D printing, this design did not work. This gearbox was the first working version to run on a NEMA 17. It has a larger footprint compared to Version 2 allowing greater tolerances and a fully functional design. This python script was based on the SolidWorks article Building a Cycloidal Drive with SOLIDWORKS. The two main parametric equations I used were: - Clone the repo - Open Fusion 360 and launch Scripts and Add-Ins ( Shift + S ). - Under the Scripts tab, click + (Plus) to add a script. - Select the cycloidal_generator folder and click Run. - Pins ( $N$ ) & Pitch Radius ($R$ ): Sets outer stationary housing geometry (Rotor has$N-1$ lobes). - Eccentricity ( $E$ ): Input shaft offset distance. (Constraint: $R > E \cdot N$). - Outer Pin Radius ( $r$ ): Roller pin radius. (Constraint: validated against undercut limit $r_{\text{max}}$). - Precision / Profile Offset: Angular step size and tolerance offset ( $+$ for 3D print clearance). - Output Pins & Bolt Radius: Defines concentric output pins and rotor clearance holes ( $r_{\text{pin}} + E$ ). Note This section is dedicated to Version 3, whose CAD files can be found under cad_models/version_3 . | Metric / Parameter | Value / Detail | |---|---| | Gear Ratio | 1:9 ( | | Outer Diameter | 9.0 cm (90 mm) | | Drive Motor | NEMA 17 Stepper Motor (42bygh40-A24dh) | | 3D Printing Material | PLA | | Primary Fasteners / Hardware | 4× M3 × 8 screws, 2× 6704 Bearings | | Tolerance Offset Applied | +0.15 mm (+0.015 cm) all around | | Gearbox Torque | 1.28 N·m ± 0.0061 N·m | | Base NEMA 17 Torque | 0.21 N·m ± 0.0061 N·m | | Efficiency | 66% ± 0.220% | - The housing pins can be replaced with MR128 bearings allowing for less friction and higher efficiency in the gearbox. - The output pins can be replaced with M2 screws with metal coverings to increase rigidity, maximum torque output, and the efficiency of the gearbox.