Various ball bearings for 4.5mm or 4.3mm BB steel balls

I designed printable ball bearings for 3/3.1mm steel balls earlier, but I told myself I want to do the same for bigger balls. I chose 4.5mm BB balls because they are cheap and easy to buy.

By combining 2 of totally 30 parts, you can get various IDs (inner diameters), ODs (outside diameters) and even tight, normal and sloppy one.

For each bearing you need 10x 4.5mm (actual diameter is 4.3mm) balls. Combine the files to get outer diameter of 22/23/24/25/26/28mm 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.

Usually, you want the “normal” one. It spins easy and has just a bit of play in it.

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 very 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 files), but scaling it in your slicer just a tiny bit should work well.

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:

The best way to assemble the bearing is to put 6 balls in the outer part, stick a finger in it and put all 6 balls in the slot. Then, place the outer part with 6 balls onto the inner part, so the balls don’t fall out by themselves. The next step is to add remaining 4 balls, which should be easily done by hand. Finally, 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/0BHkkjdRyz0