I design a new spindle holder for my CNC3018 machine, the old one had an issue with tightening the spindle. I hope you like it, use it and be happy with your own machine.

The material used by me is PLA, but it can also be used PETG, ABS ... and any other material that does not change its size when cooled. 

Use 0.6 - 0.8 nozzle for faster printing, 0.45 - 0.6 layer height, printing speed: medium-high, outer/inner shell speed: low-medium. Watch out for under extrusion. If your printer is oozing, sand carefullyy the place for the bearings.

You may need to glue or add some scotch tape around the bearings to fix them, it depends on the material you use, and the rest will be ok.