Why the obsession with TIR? Don't you just turn something and it is round regardless of TIR? It might not be centered on your piece but it will be round.
On Tue, Apr 21, 2020 at 4:02 PM Robert Downs via <wa5cab=[email protected]> wrote:
Yes, except that measuring it 4¡± from the jaws could introduce the effects of some other variables that may or may not have anything to do with the chuck.? Chuck runout figures should be taken next to the end of the chuck.
?
Although it amounts to the same thing, TIR is most commonly defined as Total Indicator Reading.
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.
