This is a pillow block for Thomson Super 8 linear ball bushings that fit 1/2" round guide rails. Not as compact as my other design, this one uses a screw to adjust "fitment" as Thomson's original design does. The design includes small retention bumps to center the bearing inside the block.
You can see all the important dimensions on the diagram. I sliced using Cura- for some reason slic3r had a hard time with this one. Printed with coex3d MG94 ABS with 0.2mm layers and 30% infill, no support material.
You'll need a 6-32 x 5/8 or 3/4 screw and washer for fitment adjustment. You'll also need 4x 6-32 screws for mounting. The mounting holes are 13mm deep.
Sorry for mixed units- 3D printers want metric measurements but metric hardware is not so common in the US.