How do you use a dial indicator?

[The Critic]

To check rotor/hub runout. I'd greatly appreciate any videos, guides, advice, etc on how to properly use a dial indicator to check rotor runout.

Thanks in advance.

 

[Merkava_4]

Dial indicators usually have a magnetic fixed base to position the instrument stationary. There might be some kind of swing arm to position the probe onto the moving surface to be measured. In the case of a rotor, I would assume the probe is positioned on the rotor surface while the rotor is turned by hand to measure the runout. The distance the needle moves in the gauge is your runout.

 

[Merkava_4]

One more thing:

If you measure .005 below zero and .005 above zero, your total runout is .010

 

[The Critic]

Originally Posted By: Merkava_4
One more thing:

If you measure .005 below zero and .005 above zero, your total runout is .010

How would I get two different readings?

Thanks!

 

[Shannow]

Your "zero" has a 1/360 chance of being the tru zero, so the guage swings both ways.

If it starts at zero, and goes to ten, is the same as starting at zero and going -5+5 through the travel.

 

[Merkava_4]

Originally Posted By: Shannow
If it starts at zero, and goes to ten, is the same as starting at zero and going -5+5 through the travel.


That's exactly right. I didn't word my post clearly enough.