Testing the backlash on my mill I grabbed my BesTest .0005" dial indicator and set it on the mill table to check the movement. Find out that when I increment the table the indicator says something different. Drive myself crazy checking everything mechanical, electrical, and software over and over.
For one test I grab a inexpensive Yuasa dial gauge to do some 1" measurements. Everything looks fine. Took out a third indicator an Interapid and come to fine that my BesTest is not working correctly.
If someone would have told me the indicator was wrong I would have scoffed at them "My B&S indicator is 25 years old and never has been wrong!"
Dan