Why four bearings on the Z rods and not just two? Questions › Category: Mechanics and structure › Why four bearings on the Z rods and not just two? 0 Vote Up Vote Down Anonymous asked 2 years ago Hi I see four bearings on the z rods? Not sure why four instead of one per z rod? Confused. Thanks 1 Answers 0 Vote Up Vote Down diegotrap Staff answered 2 years ago We use 4 bearings to form a “longer bearing” and preventing that the Y axis to tilt. You can use just two bearings too, if you think they are enough.