This thing is a derivative of the v2 X carriage found on the Github/Makergear/file repository. This design is modified to fit LM8UU bearings. This x carriage fits a Makergear extruder or bowden cable adapter.Credit goes to Xnaron's "snap in holder" design for inspiration. The carriage should fit a regular Prusa Mendel as well.I have included the Alibre design file for those who have access to this program.For best results, use a raft and suppport as it will be printed on its side.Press fit four LM8UU linear bearings. Press fit 4mm hex nuts into the holes for the belt clamp.Currently, the fit of the bearings is snug, not tight. Too tighten more you can warm the plastic and squeeze the cylinder before you re-insert the bearing. The bottom of the cylinders are slotted for that purpose. Or as someone has suggested you can drill a hole and tighten them with screws. You can also clamp the outside of the cylinders with zipties or by other means of your choosing. Last but not least, just a bit of epoxy in the slot with the bearing inserted would probably do the job.