Lathe Cross Slide Problem

[EdK]

I tried measuring the travel per revolution of the hand wheel again but used my Teclock dial indicator this time and the error wasn't as bad. Then I realized that if I didn't have the dial indicator at an exact 90 degree angle to the measuring surface, I would not get an accurate reading. So I lined up the Teclock as best as I could and it's much better. I went back and forth from my Teclock and my cheap dial indicator and my Noga and my cheap indicator holder and really couldn't nail down where all of the error is coming from. I didn't realize how hard it was to get a dial indicator at right angles to a surface in both directions. Anyway, I'm done measuring and am very happy with the results.

How does one measure the accuracy of a dial indicator anyway?

Ed