From: Sky2high@aol.com
Message-ID: <4aaaac39.35ff3eb2@aol.com>
Date: Wed, 16 Sep 1998 00:29:38 EDT
To: lancair.list@olsusa.com
Subject: Forward Hinged Canopy Construction Considerations
Mime-Version: 1.0

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A canopy is not a canape' and that's no canard.

I built my 320 from a BFB (Before Fast Build) kit, so my supplied canopy
consisted
of the Plexiglas, hardware and the outer skin.  I don't remember how much of
the
work is done in the fast build versions. So....

After the canopy skin was fitted, the Rollover attached and the "jig" frame
was 
 Bondo'ed on --

1. The plans specified quantity of uni-directional carbon and foam was not
enough to
stiffen the skinny forward center section of the canopy.  The gas springs
exert so much force when the canopy is closed that the front is squeezed
together.  This
flexing causes the front lower corner to rub on the sides of the deck joggle
as the
canopy is closed.  I added another strip of 1/4 inch foam and 4 layers of
carbon
between the canopy's hinge brackets which has adequately stiffened that
section.

2. I had to build my own sides so......
1/4 inch pre-preg was cut 1 inch wide conforming to the curve of the longeron
and
extending the length of the canopy sidewall.  This was held up from the
longeron
by 1/4 inch and microed to the canopy sidewall. Foam was built up on the
sidewall in to the inside edge of the pre-preg.  Several layers of glass and
carbon
were laid on this, extending to a half inch lower than the top of the
longeron.  This
provided side wall rigidity and the lip over the inside edge of the longeron
keeps the
canopy from bulging outward in flight.

3. The longeron-rollover intersection was curved (using micro) as was the
canopy at
this point. The 2 or 3 in radius curve allows one continuous piece of seal to
be used.

4. The rest was completed in the usual way.

Good Luck!

Scott Krueger
N92EX