Message-ID: <000301be41d9$a6713be0$2fc02299@oemcomputer>
From: "bobjude" <bobjude@gateway.net>
To: "Lancair Mail List" <lancair.list@olsusa.com>
Subject: Builder's Tip: Re Flap Hinge Points
Date: Sat, 16 Jan 1999 23:24:25 -0600
Mime-Version: 1.0

          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> 
>>
To all 2 Place Builders who have yet to complete their wings and/or flaps:

Assuming we all want more SPEED, we know that; minimum gaps at control
surface interface = minnimum drag = more speed.  The gap between bottom
hinged surface of the LE edge of the flap and the TE of the wing is
difficult to minimize.  This is because the 10 BID layups at the wing TE and
flap LE result in a thickness that puts the pivot point of the hinges above
the bottom surface.  Ideally, if we had perfectly straight edges and the
pivot point exactly at the surface, we could build  flaps with zero gap.
But because the pivot point is above the surface, we must widen the gap to
prevent binding when the faps are lowered.

It follows that if we can reduce the thickness of the flap and wing hinged
edges and get the pivot point closer to the surface we will end up with a
smaller gap.  One way to do this is to put clamping pressure on the hinge
pad layups and squeeze out the excess epoxy.

I am currently repairing my storm damaged airplane. Building a new flap and
other things.  I used the clamping technique and got a 40% reduction in
total edge thickness.  The thickness of my old flap LE averaged .216 inches.
The new one is .129 inches.  This will allow me to reduce the gap.  The
construction manual calls for 1/16 inch gap.  I could not achieve this
without clamping.  Now I think I can.

I hope this helps someone.

Bob Jude
N65BJ