On Sun, 17 Aug 2008 02:57:14 -0700, BottleBob
wrote:



F. George McDuffee wrote:

FWIW -- I have always had the spindle turning [c. 500 rpm] when
using the electronic edge finder. Also very careful sneaking up
to a contact. Light is not very bright though when it makes
contact.

Unka George:

If the electric edge finder is spinning, AND if it runs out a little,
it will probably light up when the high point contacts a conducting
surface. But you really won't know if that high point is .0001",
.001", or even .010" off center. That's why I would contact your part
with the edge finder stopped (then zero out your axis), back off your
part, turn the edge finder 180 degrees and contact your part again to
see if there is a difference in the two positions of the edge finder.
Half that distance difference should be your off-center runout
==========
Good observations, but as an old German tool maker told me years
ago, after I took a drawing to him with 4 place decimals for some
hole locations, if you can't measure it, it doesn't matter.

I see several people have mentioned the Schmidt edge finders,
https://www.hermannschmidt.com/produ...&idproduct=148
anyone have comments on /experience with the ones from Flexbar?
http://67.59.156.7/merchant2/merchan...uct_Code=18509

Are these that much better than B&S or Starrett, or just more
expensive?


Unka' George [George McDuffee]
-------------------------------------------
He that will not apply new remedies,
must expect new evils:
for Time is the greatest innovator: and
if Time, of course, alter things to the worse,
and wisdom and counsel shall not alter them to the better,
what shall be the end?

Francis Bacon (1561-1626), English philosopher, essayist, statesman.
Essays, "Of Innovations" (1597-1625).