Marble ball bearing

thingiverse

This ball bearing uses 6 marbles that are 16 mm in diameter. I got a bag of 50 marbles for a dollar at Toys R Us. This is in three pieces (two of the cage piece, and one shaft piece). I managed to put the thing together, including marbles. I'm not a mechanical engineer, and the movement is a bit rough, and catches a little in places. If you drive it with a cordless drill, it rattles because things aren't all perfectly aligned. But it does rotate. Here's a little video: https://www.youtube.com/watch?v=ie1mtN5CR90 After making the video, I took it apart and sanded the inside surfaces that touch the marbles, and the motion became a lot smoother. I used the cordless drill to help sand the surfaces on the axle. Print Settings Printer: Micro M3D Resolution: Low Infill: Yes, on the shaft Notes: I'm using the Micro-M3D with non-M3D filament (using cheat code "PUB"). What I've found is that it's good to put skinny 5mm-long legs under things to make raft removal easier. My legs are little cones, 1 mm wide at the bottom and 0.1mm wide at the top, that just touch the bottom surface of the object. So they pop off when I'm removing the supports, and I get a clean bottom surface. I used the printer's highest setting for infill on the axle, because if you don't, and then you squeeze it in the chuck of your cordless drill, it gets a bit crunched and I'm pretty sure it becomes weaker as a result. How I Designed This Designed in OpenSCAD I really love OpenSCAD but I kinda wish somebody would create a GUI for it that looks like the TinkerCad website.