Split planetary reducer Free 3D print model

cgtrader

This reducer is designed to be mounted directly on a standard stepper motor, conforming precisely to the NEMA 17 dimensions. It boasts an extremely high reduction ratio of 96.6667:1 within an impressively small space envelope - only 20mm tall and 80mm in diameter. After thorough testing, I found no noticeable backlash in the reducer's operation, but I can't make any definitive promises about how it will hold up over time. However, this design successfully eliminates any unwanted wobble that can occur in harmonic drives created through 3D printing - a critical requirement for ensuring accurate performance within complex mechanisms. If you encounter any issues with the assembly or functionality of this design, please don't hesitate to reach out so I can address them promptly and improve the design based on your feedback. Here's an overview of the key technical specifications: - Gear ratio: 1:96.6667 - Sun gear teeth: 24 - Planet gear teeth: 16 - Fixed ring gear teeth: 56 - Output ring gear teeth: 58 The reducer's operation can be mathematically verified with the following calculation: i = (1 + (fixed_T / sun_T)) * (output_T / 2) i = (1+(56/24)) * (58/2) = 96.6667 As for how it works, this system is built around two concentric rings featuring inside gearing - one is stationary, while the other serves as the output ring. Both planet gears are connected to the sun gear and simultaneously engage with both of the concentric rings. With each revolution of the planet carrier, the outer ring is advanced by 2 teeth in the direction of motor rotation. This result is achieved by adding 2 extra teeth to the output ring, then adjusting the pitch diameter of the outer ring so it matches that of one of the fixed rings. It's essential for this process to ensure proper tooth meshing. Versions: There are two versions available - a more educational setup allows you to visually observe what happens within the reducer. Additionally, there is an alternative version designed for easier mounting of an M8 bolt as the output. This setup requires a few additional parts not included in the basic assembly: mainly screws that will hold it together; Most of the holes accept M3 screws and several lengths are necessary. Prioritize installing those that go through the planet pin on the carrier since it depends on the screw for its strength, use common sense. Some Notes: It is strongly advised to lubricate thoroughly before actual use in any mechanism; a direct load applied on the output ring will be counterproductive. A mechanical support using an external bearing would make maintenance of reducer smoother and more durable; if direct mounting with external bearing isn't suitable because it could still lead slipping; this is not usually as dangerous in this case since if it fails due to exceeding holding torque under prolonged operation or sudden shock forces it can easily damage plastic casing, rather than causing irreparable harm.