I’m considering using some older brushed motors and PWM controllers to power some mech projects that will also incorporate 3D-printed gears and sync belt pulleys. Material-wise, I’ll probably just use PLA+ for those parts, but I have spools of Nylon and PC-Carbon I may also try. I can probably also persuade a friend to make a few Onyx parts.
My question is… What motor shaft to 3D-printed part power transmission approaches do you folks with experience find work best? We know 1/2-inch hex can work for some applications (Exhibit A: 3d-printed mecanum wheels on intakes this year). A few older motors (e.g. AM Gearmotors) have 1/2-in hex out, but other motors have 8mm keyed shafts, 6mm D shafts, round (unkeyed) shafts, and shafts with pinions pressed on. My intuition is… a 3D-printed part designed to mate with any of those could work with lighter loads, but with heavier loads the list gets shorter (& my guess is pinion interface is best). Not sure about keyed - it seems like wear could become a problem. One other aspect here… I’m striving for cheap, and I’d rather not use up the team’s versaplanetaries or sport gearboxes to get to hex. Thanks.