"Bill Schwab" wrote in message
...
snip----
My edge finder (actually a combined edge/center finder) continues to
mystify me a little. Per Harold's comments, I will try running it a
little faster to see what happens. So far, I don't see quite what the
instructional movies on the net show. Instead of clear side movement, I
get more of a whobble. Is that what the combined finder does, or am I
just running it too slowly?

Bill

You guessed it! I assume you're speaking of a device that has a head of
given size----such as 1/2" diameter, and is held to the main body with a
spring? If so, they perform poorly at slow speeds, as I said. When it's
running at a good speed, it will stay on center when so placed with a
finger, and ride the edge of a part without moving away until such time that
the edge of the finder no longer has any clearance. At that point, it
smartly snaps to the side. If you run it too fast, it will pull away,
often causing some damage to the finder. When you're running at a good
speed, it will simply stay off center, riding the edge of your part. Set
your dial or DRO to zero at that point, reflecting the radius of the finder,
so the centerline of the spindle is at 0, not the edge of the finder.
Once you've done that, repeat the operation to insure that you are really at
0. It's easy to overshoot the first time, but the second time you have a
clue where 0 should be. If there's any doubt, repeat a third time. You
should be able to locate an edge within a thou repeatedly.

Harold