Nema17 Reduction Gear 1:256 Rolling Tray

thingiverse

A few days ago I found a Meade ETX-70 telescope forgotten at my family's garage. It had a goto altazm mount which was broken and although i tried to fix it, it was impossible to make it work again. So with some searches around I stopped at the OnStep project, and as I had some 3D printer electronics available I decided to build my own goto altazm mount. As the unused stepper drivers I had were A4988, with only 16 microsteps, I decided to design a nema17 (which I had a couple of them) reduction gear with a 1:256 ratio tied to a stable rolling tray. Both, the reduction gear base and the rolling tray have a few embedded nuts to be used as anchor points to fit it as a building piece for my altazm mount. As I'm not a mechanical engineer I've done my best to design the gears and the final device seems something between victorian and steampunk but as far as I've been testing, it works faultlessly. I've added some photos and a video of my work in progress. https://www.youtube.com/watch?v=YmEpXjb6Fo0 Extra materials: --------------------- ### Gears axis * 2x M6x50mm Screws * 2x M6 Nuts + Washers * 8x F686ZZ bearings * Add printed M6 spacers, 1x1mm, 1x7mm & 3x2mm ### V-Slot Wheels * 3x M5x30mm Screws * 3x V-Slot M5 T-Nuts * 3x V-Slot M5 V-Wheel * Add printed M5 spacers, 6x2mm ### Anchor Points * 12x M5 nuts (or autoblock nuts but maybe PLA won't support tightening tension) ### Other * M3 Screws for nema17, stepper gear and covers * Nema17 stepper motor I'll publish the full mount assembly as soon as I have it working properly. UPDATE: You'll need to print 3x gear_10-40.stl. Look at the section view to see all three gears distribution.