608 Bearing Guide for Prusa Mendel
Published on March 26, 2012
Printable Ball Bearing Upgrade
I modified the bearing guides from Prusa Iteration 2 (https://github.com/prusajr/PrusaMendel/blob/master/source/bearing-guide.scad) that was designed by Greg Frost. The original has the outer race on one half and the inner race on the other half. There was also a 0.3 mm allowance between the two so that when put together, it's hard to make them concentric. My modification puts the inner and outer races on the same half and removes the clearance. On a properly tuned 3D printer, the two parts snap easily together. If the printer is not quite tuned right, the printed parts are more likey to be usable than the old design.
Print 3 copies for a Prusa Mendel Iteration 2. There's a clearance parameter in the SCAD file that was fixed at 0.3 mm in the original file. With my Mendel and slic3r, I found that the inner part was too loose inside the outer part with this clearance so I set it to zero. This resulted in parts that snap together easily. The two parts must be glued together. I recommend allowing acetone to seep between the parts if printed with ABS.