Summary

This magnetic coupling is composed of two halves: one half, the Bearing Coupling, press fits onto a ball bearing, and the other half, is the Cylinder Chuck, which has a hole in the center for a rod. One half is press fitted with cylindrical teeth and meshes into the other half.

Instructions

Required parts:

A. Cylindrical rare-earth magnets x 6
B. Plastic rod (Acrylic works well since it will weld to ABS)
C. Ball Bearing
D. If using ABS, press fits should be done with acetone

Directions: (assume teeth go into Chuck here)

Fit magnets into side holes in both Chuck and Coupling. ENSURE proper pole alignment so the pieces will not repel each other.
Cut 3 pieces of plastic rod to fit into the Chuck. The lengths of the rods should be long enough to fit well into the chuck and extend into the Coupling, but without creating a gap between the two.
Cut another piece of rod to fit into the center of the Chuck. The length is up to you.
Press fit the Coupling into the ball bearing; if using ABS, acetone helps very well with this.

Magnetic Coupling