This is a simple thrust bearing designed in onshape for a gas pump project I was working on. The movement has been surprisingly smooth and has shown no signs of wear as of yet.

Print instructions
Print 1 of each file except ball bearings, that you'll need 6 of.
0.2mm layer height for all parts worked for me just fine with my Ender 3. The more walls and infill, the strong the piece will be. The finer resolution on the ball bearings, the better.

Assembly

1. Put the outer casing on a table, flat side down.
2. Insert the bearing washer making sure it sits flat inside the outer casing.
3. Place a ball bearing into each outer hole of the bearing washer.
4. Fit the inner casing into the outer casing.
5. OPTIONAL: Spin the bearing under a light load to grind away friction points.
6. OPTIONAL: Add a light oil like WD-40 to the ball bearings to reduce friction.

Important Dimensions

• Outer casing width: 35mm
• Outer casing depth: 9mm
• Inner casing receptacle diameter: 5mm