Planetary 'harmonic' reducer, 96.6667:1

pinshape

This reducer is designed specifically for mounting on top of a standard NEMA 17 stepper motor. Its impressive reduction ratio of 96.6667:1 fits into an incredibly small package, measuring only 20mm tall and 80mm in diameter. Thorough testing has revealed no signs of backlash, but it's essential to note that prolonged use may still cause some issues. This design effectively eliminates the wobble often observed in 3D printed harmonic drives, a crucial feature for accurate mechanism operation. If you encounter any problems with this reducer, please contact me so I can refine the design based on your feedback. Basic Technical Data: Gear ratio: 1:96.6667 Sun gear teeth: 24 Planet gear teeth: 16 Fixed ring gear teeth: 56 Output ring gear teeth: 58 Ratio calculation: i = (1 + (fixed_T / sun_T)) * (output_T / 2) i = (1+(56/24)) * (58/2) = 96.6667 Functioning Principle Explanation: This system consists of two rings with internal gearing, one fixed and the other as the output ring. Both planet gears are driven by the sun gear, engaging both rings simultaneously. Each revolution of the planet carrier around its axis will move the outer ring by 2 teeth in the direction of the motor. Achieving this is possible by adding 2 extra teeth to the output ring and adjusting the outer ring module to align its pitch diameter with one of the fixed rings for proper tooth meshing. Versions: An educational version is included, allowing you to observe the reducer's inner workings. (Print 'tr17_edu' instead of 'tr17') There is also an alternative version of the output ring designed for easier M8 bolt mounting. Additional Parts: You will need additional screws to assemble this reducer. Most holes accept M3 screws; various lengths are required, with the most crucial ones being those that secure the planet pin on the carrier through a screw for added strength. Excluding some screws is possible, but using common sense is recommended. NOTES: If you plan to use this as part of a functional mechanism, apply plenty of grease or lubricant. Do not directly load the output ring; instead, use an external bearing to prevent wear on the reducer. You can, however, use it as a direct source of torque without bearings, but be cautious not to exceed the ratio*motor holding torque, lest the drive may slip.