Closed Bearing Block for 1" round unsupported rail

thingiverse

This is a closed bearing block for a 1-inch round, unsupported rail. It's a variation of my open bearing block inspired by WWWektor's contribution. The closed version was designed to minimize the springy nature of the open block under the increased pressure of aluminum cutting. I haven't tested this bearing block yet. I'll report its performance when I do. I'm re-working my open bearing block (for a fully supported 3/4-inch rail) and will upload that model when it's ready for testing. These blocks use an affordable bearing with a 22mm diameter and 8mm center hub. The rods are cut from 8mm steel rod, similar to 3D printer rails. The shaft holes (voids) in the block are for 8mm shafts. The bearing cut-outs are wide enough to add spacer washers on either side of the bearings during installation. There are two shafts, 75mm long, and four shafts, 50mm long. The shaft holes must be drilled just enough to accept the 8mm rods. I found that it's not necessary to use 5/16-inch nuts and bolts. It added a lot of code for the hex cutouts, and the nuts interfered with the bolt heads when installing the bearings. Two of these blocks fit into a 3x3 inch (interior dimension) aluminum square tube which is welded to the aluminum gantry sides. The main rail passes through both blocks, giving very good strength and no measurable slop.