Hi first post on here, not sure whether it was the right section but here goes.
Have a hard time getting within tolerance when either milling or drilling a 16mm hole off center.
The tolerance is +-0.05 degrees but when mesuring with a zeiss accura we come always + 0.4 even when compensated.
The piece is 123x900 and we use both center and supportbearing (have tried with one of each)
Even tried c-axis rotation from rapid to feed with no results. Anyone have an idea what the issue may be?

Note that every measure was on the same piece but redone further in for testing.