Bearing preload on y gantry

I noticed that some of my bearings weren’t touching on the y gantry. I saw the procedure to adjust them in another thread. It said you could disconnect the Y stepper and test that the gantry moves from one end to the other. It didn’t mention how much preload you should have on the bearings. Too much and you could prematurely where the bearings or the tube or cause the stepper to stall. If I adjust mine so it moves really freely I’ll always have a couple bearings that don’t make contact with the tube. If I adjust so they all make contact there is some resistance when moving from end to end. Has anyone quantified the amount of preload for these bearings?


I was wondering this myself while doing my initial preload.

I read the instructions as telling me to adjust until one of the two bearing were touching, then move to the next one. When I adjusted so both touched it felt like there was some resistance. I don’t think there are any torque specs for these as I imagine they would be different for each machine.

Perhaps verifying the frame is square would be another thing to check?