BobH wrote:
Karl Townsend wrote:
There's been a role reversal at my place...

Whenever "The Kid" is home, I watch him machine to learn. he edge found
a part (in 15 seconds!) by flicking the edgefinder to make it wobble
and then turning the crank till it was on center.

I've always cranked till the finder "kicks" to one side. I don't have
his accurate eye sight and feel to do it that way. My results weren't
as repeatable ( I tried after he left) so I'm back to the "kick"

I use the method your son uses. It just seemed like the obvious way to
me. So if you touch the work with a spinning edge finder it will kick to
one side? I will try it and see how it goes.

The instructions that came with my edge finders say to use the kick. I
hadn't heard or thought about that idea until I read the instructions and
tried it.

I certainly feel like using the kick makes the edge finding more
repeatable. But I do wonder about what the true position of the edge is
when you use the kick method.

Since I don't own a mill and have only used my edge finders with the
school's mill, (and the class is now over) I can't spend the time to
experiment and try to answer that question. The idea of assuming it's
5/10,000 over suggested by the OP seems reasonable.

I guess to experiment, what I might do is machine a piece to an accurate
width. Locate it with the edge finder, and then machine 1/1000 off
opposite edges with an offset so I could mic the new widths relative to the
old width, and relative to each new cut and see how the numbers worked out.
That is, I would leave the piece so I could mic it from an old edge, to one
new edge on one side, and from the other new edge to the opposite old edge,
and then from new edge to new edge.

The goal of course is to find a way to use the edge finder so that these
1/1000 cuts would take an equal amount off of both edges after setting the
location with the edge finder.

--
Curt Welch http://CurtWelch.Com/
http://NewsReader.Com/