Starrett 827 Edge Finder question

[jgarrett]

I have read various articles and Starrett's web site on how to use this tool but it don't behave. I chuck it up in the mill and move the table untill it just touches and goes concentric, now as I understand any further advance of the table should cause it to go off center and wobble. Well it don't. It will get noticably off center and still won't wobble. Am I doing it wrong or is something wrong with the tool??? The mating surfaces are very smooth and no dings. I can just touch the work piece until it goes concentric and raise the Z axis to clear the piece and then it will wobble.
Julian

 

[tattoomike68]

here is how I use one.

I put a parallel in the vice with it sticking up from the jaws and edge finder wiggeling. bring the edge finder up to the parallel from the top side. (if you are looking down at the vice have the edge finder on top) touch it till it just touches and goes concentric. from there go slow untill it walks off to the side a tiny bit.

Thats .100" from the edge, lift the quill move the table in .100" and set the dial to 0. Zero the dro too if you have one. By timing the dial to the vice edge you can always reset a dro thats been re-zeroed.