Really basic TIR question

[digiex-chris]

I think I understand Total Indicated Runout. I havn't been able to find any practical examples on the net that clarified it, so I'm going to try.

-Chuck up a piece of something in the lathe.
-Mount a dial indicator to the cross slide, and touch the work with it
-Rotate the chuck so the indicator indicates a minimum reading. Zero the indicator here.
-Rotate the chuck 180 degrees, which should be the maximum reading. This is the TIR.
-eg. if there was a 0.001" difference between the minimum and maximum, the TIR was 0.001".

Did I get that right?

 

[doc1955]

Correct it would mean your material is .0005 from being centered half of the TIR.

 

[digiex-chris]

much thanks. best I could find for acronym definitions was variations on "a measure of runout".