Someone suggested to make a hand roller using my printed gear bearings - so I did, also throwing in a spiky texture.

Printing:

• This model requires good precision and a well dialed-in printer and filament combination!

• Main parts:

  • bed contact area is small for the rollers, good bed adhesion is a must - otherwise try a brim.

  • standard settings

• Bearings:

  • print 4 of these

  • 0.17mm layer height

  • random seams

  • elephant foot compensation (e.g. 0.15)

  • if unable to break free, see tips here.

Assembly:

1. Break free and break in the bearings. Use one of the axles as grip to turn the gears a couple of times. Maybe apply some pressure on the outer ring while doing so, from multiples directions. I often use a power drill with the axle clamped in.

2. Optionally use a tiny bit of light oil as lubricant for the gears for extra smoothness.

3. Push one(!) bearing into a roller cylinder. Make sure it doesn't get tilted, push hard, it needs to sit flush.

4. Insert axle from the other side, the end sticking through the bearing.

5. Push second bearing over the axle into the roller. It needs to sit flush with the roller, the axle sticking out on both sides.

6. Do the same for the second roller

7. Push both rollers into one connector cap.

8. Attach the other connector cap

9. Firmly press both connector caps so they click in, the axles should sit flush in their holes, see images.