Printed jig for metal CNC bearing

thingiverse

It's important to have a well supported linear rail system if you ever intend to cut through thick metal using your CNC mill. It's unfortunate that professionally made bearings can be so pricey. Several makers in the past have come up with great ways to machine their own homemade railing from the 1/2" steel rods you find at hardware stores, but so far no one has yet attempted to make their own bearings, at least to my knowledge. I've designed a jig you can print out in order to do so. The jig can be wrapped around a 1" aluminum cube, allowing guide holes to be drilled for the screws and bushing. To make an entire CNC machine, you'll need 12 of these. This translates to approximately 1 foot of 1" aluminum bar stock. You can find this available on amazon for less than the cost of a single 4 pack of bearings. video Instructions Download and print bearing-jig.stl. Wrap the jig around a 1" (30mm) aluminum cube. You can cut such a cube from 1"x1" (30m x30mm) aluminum bar stock. It not important how long you cut the block, so long as the sides are orthogonal to one another and can rest soundly in the jig. With the jig in place, drill a set of five 1-3mm holes to match the holes you see on the jig. Switch out your drill bit and enlarge these to 4mm. Use an M5 or 10-32 tap to thread the four holes on the bottom of the piece. These will allow you to connect the bearings to a board. Enlarge the remaining hole to 1/2" (12mm) in size. You may need to use several drill bits to accomplish this. After the hole is drilled, use a saw to remove a 3/8" (10mm) clearing in the thin wall that you created while drilling. File the walls in and around the hole as needed until the bearing is able to slide easily through a 1/2" supported linear rail.