Novice question here... I see everyone is giving a TIR (Total indicated runout) reading but not how it was measured. Over a year ago I purchased a Sanou 6¡± 3 jaw chuck along with a backing plate that was predrilled but needed the boss and face machined to fit. When done I put in a precision ground rod and measured it 4¡± from the tip of the jaws. The TIR reading was .002. I was very happy with the results. Is this the correct way to measure the runout of a chuck? I did it this way because I did not think that measuring?just the diameter of the chuck is accurate enough.
John
Chipbreaker13