If you need bearings for 3D printed mechanical parts, you can buy and use standalone factorymade metal bearings or you can 3D print them. 3D printed bearings could be made of any reasonable size and you can integrate their races directly into your design.

In this video, I show how to design and print these bearings. I explain how bearings work and then show how to design them in CAD (I am using OnShape). In the end, I show a few useful slicer options that could increase printing quality.

This design is available in OnShape:
https://cad.onshape.com/documents/3ea...

STL files:
https://github.com/PositiveAltitude/b...