After drawing a few things and making a few cuts I was ready to make a spoil board. I found that after trying to surface a test board with a ¾" surfacing bit that the spindle wasn’t perpendicular to the surface. So I read up in the forums and printed the tramming jig. Sure enough its not perpendicular. It’s about 1.2mm off --which IMO is too much to correct with shims. I loosened and re-tightened the center section following the directions and it was slightly better – went from 1.5 -> 1.2mm
I noticed that the center section is rotating slightly around the X axis - ie. the Y axis is riding on the top bearing only. No rotation occurs around the Y axis. What needs to be tightened ?
If a triplet of bearings isn’t touching, you should be able to tighten the tension bolt for that triplet. But don’t over tighten. If it is already tight, maybe Ryan or someone else with more a more mechanical mind can come up with a suggestion.
If you get that touching and you still have a consistent 1.2mm error, don’t be afraid to shim it. A small shim may be enough to move the tip of the screw 1.2mm way out at the end.