May 2, 2022
Description
Enhancement on my previous Curtain Gear project due to multiple shortcomings, using the carrier (planet fixer) to drive the output with a higher torque, and having the ring fixed against the NEMA17 motor. Modify the source file if you have different dimensions.
Significant tweaking is still required on this model! I've given up on trying to make it work due to some friction, gearing, shearing, and tolerance problems. Said problems have significantly decreased the output torque, or have made the mechanism unstable. So I've decided to buy a metal gearbox for NEMA17 from StepperOnline and save myself the headache from hereon in.
OEM, 4mm diameter balls connected by 2mm of string
5mm D-shaft (0.5mm inset). With a 9mm long cylindrical shaft before the D chamfer begins. (L = 40mm). With my calipers, I've found that the depth of the M3 mounting holes are 5.5mm, but I've designed it around a 5mm depth.
7:5:17 gearbox with the torque step-up of 2.4x. Backlash is minimal due to improved tolerance testing, both on the D-shaft and within the herringbone gears.
22 slots with 0.25mm tolerance. Gear radius of 21mm and outer diameter of 44mm. Which means it is barely larger than the profile of a NEMA17 motor (42.3mm wide).
License:
Creative Commons — Attribution — Share Alike
7
thinkier
