6mm BB Bearings (Includes .f3d)

6mm Based Bearing:

Generally suitable for low speed, moderate load applications. Lubrication/material modification would yield a more resilient bearing.

Sizes:

Bearing is available in:

10mm ID, 20mm OD (requires 10 BBs)

20mm ID, 30mm OD (requires 15 BBs)

30mm ID, 40mm OD (requires 20 BBs)

(Fusion360 .f3d file is provided and any size you want can be designed/modified under a creative commons attribution-noncommercial-share alike licence)

You can use any type of standard 6mm BB (Plastic/Steel). Airsoft BBs work fantastic due to their cost and availability. (By all means try to print 6mm spheres.)

Noise is minimal but not negligible without lubrication. Using a thick grease such as lithium/silicon grease reduces noise significantly.

Assembly:

See attached diagram.

1. Place the two lower races (they have tabs) on a flat surfaces nested inside each other.
2. Insert X amount of BBs to fill the space between the races to fill them (Do not overfill races. Bearing will not function or will be high in friction. A small unfilled gap is normal)
3. Take the outer race and orient the curved surface face down. Press hard to clip the two halves together. (This may take some finesse. DO NOT lift the assembly off the surface until completion of the next step.)
4. Take the inner race and orient the curved surface face down. Press hard to clip the two halves together. (This may take some finesse. ) The bearing is now ready to use.

(If the upper races are too loose it is possible to carefully apply CA glue to the seam between the upper race and the tabs. Avoid getting CA glue into the races. This shouldn't be required however.)