Various ball bearings for 3/3.1mm steel balls

thingiverse

Bearings you can create: 634, 625, 635, 685, 696, 606, 626, 636 And many different bearings with various dimensions. For each bearing you need 10 3.1mm (or 3mm? Read the whole description) balls. Combine the files to get outer diameter of 16/17/18/19/20/22mm and inner diameter of 3/4/5/6mm. All bearings are 6mm in height. For one bearing you need one outer part and one inner part. The "tight" one has much less play in it, but still spins relatively easy. At high RPMs it might get hot and destroyed but for common purposes (3D printers, CNCs or whatever) they should work very well. The "sloppy" design is not as sloppy as it sounds, but it is recommended to print that one for higher RPM and low friction. If you spin it by hand it will keep spinning for a short while. There is a slight chance that your printer will print it differently and in that case you might need a little adjusting. To customize it in AutoCAD would be the best option (I did include the .dwg file), but scaling it in your slicer just a tiny bit should work well. So I ran out of bearings and even though I ordered like a hundred of them, it hurts for me to wait... In Slovakia, small bearings are priced at 5€+.. So I decided to try and design a ball bearing, since I had some steel balls in a box (all came from ball bearings a long time ago). I measured the balls and the smallest one were 3.1mm. 3.1 is an odd number and I believe my digital caliper is wrong. I didn't find any information about the use of 3.1mm balls in bearings. Anyways, I designed a bearing for these balls and they work nicely. It is very hard to take the inner part out but if needed, along with severe destruction it is possible by tearing the outer part with cable cutters. Printing: I myself am printing them from PLA and it works fine. ABS should work better though. I suggest printing at 0.1mm if you can, I'm printing at 0.15 and everything is fine. 0.2 should be okay too. Nozzle size should not matter, but mine is 0.4mm. Assembly: To assemble them, hold the outer part slightly above the inner part to insert 10 3.1mm balls into the outer part (no force required) and finally, as you apply some force from the top (you can use pliers or put it in the vise, though, hammer should work as well) until the inner part snaps into the center. Watch the video: https://youtu.be/--9aDPPiXN8