Doug Hoffman wrote in message . com...
In article ,
(Chip Bearden) wrote:

Be aware that the gauge alone will *not* detect errors in the shape of
the profile or thickness of the wing. For that you need accurate
templates.

Actually, it is possible to do *some* profiling of the wing using a
dial gauge. You need the airfoil coordinates and the dimensions of
your dial gauge (the distance between the contact points of the
"feet", and where between the feet is the dial gauge). This assumes
that the thickness is correct and that the very nose of the leading
edge is also correct, two big assumptions.

Chip, Please accept my apologies for dismissing this idea. After
taking a hard look at my dial indicator readings, comparing them to what
I see on the wings, and thinking more carefully about the method you
describe, I understand what you are saying and see how this could work.
It's actually a pretty clever idea. Sorry again.

Regards,

-Doug

No apology necessary. In 1985 at the U.S. 15M Nationals, Walter
Schneider (of LS fame) took one look at my dial gauge as I tried to
explain what I'd done and had an even more dismissive reaction.

Regarding the idea, as I said earlier, an article in Technical Soaring
provided the basic theory. I just took it a little further and applied
it to profiling.

Also as I said earlier, using templates is a more accurate approach
and is the one I'd recommend. But if you've got the wing profile
coordinates and don't want to go to the trouble of making good
templates for multiple stations on the wing, the dial gauge approach
could be of help beyond just locating localized bumps and depressions.

Chip