Linear bearing for square tube - using skateboard bearings

grabcad

This is my design for a cheap but sturdy, durable linear bearing for metal square tubes (Aluminum or steel). Depending on the size of the tube, type of bearings, bolts, thickness of the side plates, you can modify the design to adapt to your needs. In my case, I used 3/4" (18.9mm) aluminum square tube, 8x16x5mm bearings and M8 bolts (to fit in 8mm ID bearings) and 5mm thick ply wood for the side plates. I didn't really need to do much test with my 3018 CNC machine and everything was assembled nicely together. The linear bearing was sliding very smoothly on the tube and there was not not really any type of play that I can notice with my hands. The side plate can also be cut with harder materials (aluminum or steel) for more sturdy, and heavy duty use (CNC machine and Plasma cutter).