Dick Johnson's wing flattening jig?

On Aug 21, 2:55 pm, ryanglover1969 wrote:

Very interesting indeed!

Blather aside, I'm thinking that the tool in question is a waviness
gauge such as the one I made for checking plugs and molds:

http://www.hpaircraft.com/hp-24/upda...october_04.htm

My experience, backed by template checks on a variety of sailplanes,
is that getting the waviness below .004" is a lot more important than
making the airfoil exactly match the intended contour.

Thanks, Bob K.

http://www.hpaircraft.com/hp-24

On Aug 22, 12:15*pm, Bob Kuykendall wrote:

My experience, backed by template checks on a variety of sailplanes,
is that getting the waviness below .004" is a lot more important than
making the airfoil exactly match the intended contour.

And after about a half hour of gauging the spar dips and bumps on
ships at your local airport, you can give the gauge to someone else
because you'll be "calibrated". A 0.006" wiggle is quite noticeable
by hand. 0.003 starts to feel pretty smooth.

-T8

On Aug 22, 9:38*am, T8 wrote:
On Aug 22, 12:15*pm, Bob Kuykendall wrote:

My experience, backed by template checks on a variety of sailplanes,
is that getting the waviness below .004" is a lot more important than
making the airfoil exactly match the intended contour.

And after about a half hour of gauging the spar dips and bumps on
ships at your local airport, you can give the gauge to someone else
because you'll be "calibrated". *A 0.006" wiggle is quite noticeable
by hand. *0.003 starts to feel pretty smooth.

-T8

when I finished the wing plugs for the HP-24 they were easily within .
003, by the time we were able to make the molds the plugs had
developed a few creases where the foam core butted together. now that
the wings are made, and I've sprayed a bunch of high-solids primer on
them, there are no wiggles or waggles anymore............after I spray
the top coat and go thru the various grades of wet paper, they should
look and feel very nice.

Brad

On Aug 22, 12:15*pm, Bob Kuykendall wrote:
On Aug 21, 2:55 pm, ryanglover1969 wrote:

Very interesting indeed!

Blather aside, I'm thinking that the tool in question is a waviness
gauge such as the one I made for checking plugs and molds:

http://www.hpaircraft.com/hp-24/upda...october_04.htm

My experience, backed by template checks on a variety of sailplanes,
is that getting the waviness below .004" is a lot more important than
making the airfoil exactly match the intended contour.

Thanks, Bob K.

http://www.hpaircraft.com/hp-24

BLATHER! You call JJ's safety device blather?
Geez. It makes as much sense as a lot of what I read on here.
It's raining and I'm stuck in the shop. This is my only relief so
humor me.
My experience differs from yours. A wave free wing with the wrong
contour may , and commonly does, result in a smooth P.O.S. A lot of
ships, particularly older ones, don't have the leading edge contour
correct. This can have a larger effect on performance than waves.
And- once you put the gage, or in my case my hand, on the wing and
find a wave, how do you decide what to do about it? The obvious
answer is sand the high area off. As often as not, this is the wrong
thing to do.
Sanding wings is pretty much the last thing you do to improve
performance, after doing all the other things that are easier and less
likely to go wrong.
UH