compound curves in plywood

"Morgans"
:


"COLIN LAMB" wrote

I have built a number of cedar strip canoes and kayaks, and the
process is simple and beautiful.

The same technique could be use for aircraft. I have taken my canoe
through
rapids, over small water falls and survived collisions with rocks.
The
same
technique should work for a lightweight aircraft.

One problem is that for an airplane, there are bunches of point loads,
like the spar, engine, and landing gear. There are also some wicked
bending moments involved. If you canoe breaks, you go swimming. If
you airplane breaks, you......


Well, in this case, there's no engine, of course, unless you count the
mounting of the pilot as a gravity engine.

The loads for the gear, strut points, wing attach and boom are all
distributed through formers, which are in turn held in place by the skin.
The alternative is 1/16 ply wrapped between each adjacent set of formers
and scarfed to it's neighbor, which doesn't appear to be any stronger than
a planked setup which basically amounts to a whole lot of stringers. They'd
have to be kept thin to keep the weight down, of course.