Criterion Boring Head Runout

[rgray]

I put a piece of ground .75" in the center holder and centered slide so I wasn't reading offset in that direction

Did you try adjusting the slide to see if the indicator reading decreased? If your truly on zero it should only increase.

I couldn't figure out how to accurately measure the location of the 1.5 x 18 threads, i.e. if they were centered with the spindle or not

Indicating on the outside of the upper part of the boring head may give an idea. I would think it would be concentric with the threaded part. Depends on how it was machined originally.

 

[kd4gij]

First the set screw will push it to one side. That thing should do just fine.