Homemade linear bearings for 12mm rod. Initially, 2 versions of the bearing were included, one with 8 teeth and the other one with 10 teeth, so just choose the right one according with the tolerances of your print and print it.
It should work just fine.
More pictures will be included asap.
Select the right file based on the tolerances of your printer.
Use any material as you like, PLA or ABS are fine as well but Nylon should work better.
Nozzle size should be less than 0.5mm.
Any questions just ask it.