Summary I've updated this to make it compatible with my IGUS drylin bearings. I've added three more models with different hole sizes to fit, depending on how your printers dimensional accuracy holds up. I found the 15.25mm was a good fit on the IGUS bearing, If it's too tight the bearing will be crushed and pinch instead of sliding freely. If in doubt as to which size pick one and just print 4mm or so and try it. Obviously it shouldn't be too tight or loose, so test it on a 8mm rod to make sure. This is a linear bearing holder that was designed to be a direct replacement for the aluminium holder that is used in many 3d printers. I wanted to be able to use 3d printed LM8UU size linear bearings but didn't want to dismantle the aluminium ones. to assemble them. The bearings should be a tight(ish) push fit. Just file to fit if needed. Plus this should be much lighter than the metal ones so less mass to move around. After some testing, using the printed toothed linear bearings below, the printer is so much quieter. http://www.thingiverse.com/thing:18219 Please comment if you have any suggestions. I've checked the dimensions are the same as my original aluminium ones.