Inconsistent spin grinding results with a Foley

1) If the "untrueness" of the shaft is due to distortion during manufacturing/welding and the diameter of the painted shaft is consistent, then indicating between each blade and using the average reading on each end may yield good spin grinding results. 2) If the "untrueness" of the shaft is due to paint thickness inconsistency, then indicating the shaft would be useless unless the paint is removed.