WARNING: print at your own risk, pieces may not fit without sanding!!!
Compound planetary reducer for NEMA17 (40:1)
Enclosed version with all tolerances adjusted for 3D printing!
This reducer is designed to be mounted on top of a NEMA 17 standard stepper motor. It has a high reduction ratio of 40:1 in a very small package (only 17mm tall, and sized the same as NEMA17 motors (width and length of the housing).
Gear ratio: 40:1
Functioning principle explanation:
This system consists of 2 rings with inside gearing, one is fixed and the second is the output ring. All three planet gears are driven by the sun gear, and engage both rings at the same time.Each revolution of the planet carrier (here non-existent, but imagine it's there for the sake of easier explanation) will move the outer ring by 3 teeth (in the direction of the motor).
The most important part you will need to successfully assemble this is a R-1650ZZ bearing (or similar, 5x16x5), the bearing should be press fitted into the output flange and onto the motor shaft. You will need at least 4 M3 screws to fasten this to the motor, and adittional 4 screws to fasten the cover plate.
- If you plan to use this as a part of a functional mechanism, use plenty of grease or other lubricant!
Drawing with main dimensions: