The reason for using this over a fully printed ball bearing is that the balls print poorly. Now this might have something to do with the fact that I always use a layer height of .05, but I've printed this https://www.thingiverse.com/thing:252694 in 608ZZ scale and the balls come out great. I think the only reason it doesn't work yet is that it was too small and my method of freeing it up wasn't effective. I printed this in 608ZZ scale and it didn't even remotely work. Now I'm going to have to try this, https://www.thingiverse.com/thing:2317598, but as of now it was a worse fail than a ball bearing.