This is the second bearing I have made. I learned a lot from my first one. before designing the bearing I printed a test plate with many gaps of descending size. I found the 1/64 inch is as close as the printer can put two surfaces without them touching on the X and Y axis. The gap between the roller and the case is 1/64 on each side for a total of 1/32 play on the X and Y axis. The rollers spin decently but I need to add a spacer plate to the rollers so they don't touch, or change the roller diameter. And make the gaps 1/80 so that the PLA just barely bonds, and a tiny bit of torque will break it free.(Prototype Bearing 3) The bearing does work well.FF Creator Pro Extrusion Fan:YES PLA 1.75 mm Raft: YES Head speed 50mm/s Feed speed 41 mm/s extrude temp 210 plat temp 65 No Scaling Build time 8 hours (Fuk)