UPDATED 7/20/15 to include models for 688 Bearings.Inspired by:UM2 Filament Guide by Labern https://www.youmagine.com/designs/um2-filament-guide & Low friction UM2 spoolholder by IRobertI https://www.youmagine.com/designs/low-friction-um2-spoolholderI didn’t like the way the stock Filament guide on the UM2 was fixed and added extra friction to the feeder assembly and a groove was beginning to wear into the guide also.  I created one that would utilize a bearing and a more robust mounting design. There are designs for 608 and 626 & 688 bearings included. I have only printed and tested the 608 assembly as those are the bearing I had on hand, extra from building IRobertl’s Spoolholder. Please let me know if you use the 626 or 688 version if there are problems that need to be corrected. I chased the M4 threaded hole with a tap but you may not need to if you print the part a small enough layer height. All the parts should print without support except the base bracket which will require some support in the recess on the bottom side.ASSEMBLY: Insert the bearing into the male wheel, and thread the female wheel onto the other side. Take the bolt, assemble the washer, the bearing assembly, and the bracket. Insert the plug into the recess in the bottom of the bracket (refer to the exploded view for correct orientation). Thread the mounting nut loosely onto the bolt (just a few threads). Take the assembly and push the mounting nut through the large hole side of the mounting slot on the machine. Slide the assembly over, the base of the bracket should sit flush with the back of the machine and the plug will fill the rest of the mounting slot. You should then be able to tighten the bolt to complete the install.