Curtain Gear + Gearbox v2

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. Warning 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. Dimensional Information Curtain Cord OEM, 4mm diameter balls connected by 2mm of string NEMA17 Motor 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. 📷 Image redacted — claim this model to add your own media Herringbone Gearbox 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. Curtain Gear 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). Physics Input Torque (of NEMA17): [email protected] Radius of the Curtain Gear: 21mm Theoretical Angular Force Output (at 21mm): 55N Distance between the center point of the planets and the gearbox: 12.3mm The carrier moves at 7/24 the rate of the sun gear. (ie. ~686 steps per revolution.) Changes on previous design Uses the Planet Carrier as output instead of the Ring, increasing the torque Removed the motor mount / carrier fixing hub Ring is now mounted directly on the NEMA17, reducing the size Fixed a bunch of tolerance issues Uses ball bearings now (since I'm using the planet carrier as the output) Bill of Materials NEMA17 (1703HS168A) Stepper Motor x1 623-2RS Ball Bearing (ID3, OD10, H4) x6 M3 35mm Screws x7 M3 Nuts x6