I picked up a Co-Ax off ebuy a few years ago, and I'm getting my
money's worth out of it. Bought the 3" inside feeler, and was stumped on
why it wouldn't pick up on a 1.375 bore...

Manly-man adventures deleted. The secret to adjusting the swept diameter
is to pivot the feeler outward. The phillips screw just above the feeler
socket is the pivot for the feeler assembly. You can loosen it up or
tighten it with the phillips screw / acorn nut. Duh.


To answer the question of what the Co-Ax measures, the dial says
(Quote).0005" AXIS

Does that " stand for inches or minutes?

The dial graduation is divided such that each division represents .0005"
(0,01mm) of axis offset (deviation from true location) when the feeler
is tracing a diameter of two inches. This will vary slightly with feeler
angle. - manufacturer's instructions

http://longislandindicator.com/p5.html

Place the appropriate feeler in the indicator rocker bracket and secure
it with the thumb screw. Position the rocker bracket on the rocker
friction joint such that the small indicator hand is centrally located
on its graduation scale when the feeler is in operational contact with
the work piece.