I used to work in a gear shop and had to repair gear shafts that had been
centerdrilled and had more then the .001 runout that the print called for.
I used a steadyrest with ball bearing rollers and that gave me dead true
runout. It is best to collet or chuck on a small part of shaft and let the
steadyrest pull the shaft to dead true. Then I hand ground a 30 degree
angled tool to form one side of the centered part. Imagine half of a
centerdrill without the drill part in front of the angle. If you blue up the
center of the part you can see it cut the high point of the runout till it
is dead on.
Jim