wrote:
wrote:
Suprisingly I keep coming back to wood as material for mass production
since the whole of the structure could be made of one material. There
are obvious logistic benefits there, and I think most wood techniques
could be practically achieved robotically.

Wood, especially good wood, is getting scarcer all the time.
Consistently good wood is hard to find. It's the reason ladder
manufacturers went to aluminum and/or fiberglass a long time ago. The
big Sitka Spruce and other types of trees that gave us good
aircraft-grade wood mostly went to build houses a long time ago when it
seemed we'd never run out of the stuff. What's left is protected in
parks.

Understood. Which is why I was interested in plywood monocoque designs.
While domestic supplies of quality timber are depleted this is not so
everywhere. This is not a major factor IMHO because I forsee the
markets for new aircraft forming primarily overseas. So that would
resign a new aircraft company to building its factory in perhaps China
or one of the former Soviet states, or even Africa perhaps. (When you
weren't dodging bullets, graft, malaria, etc. etc.)

Wood also needs more care in storage; it doesn't survive well
in moist conditions, especially warm, moist conditions, and the heat of
an intense sun can dry it out beyond the ideal 15% moisture content and
make if brash. Glues suffer in the heat. Wooden airplanes burn easily.
Gluing wood in the factory is a tedious affair, requiring a lot of
clamps, patience, and accuracy the first time. You can't CNC-punch
wooden sheets like you can aluminum.

Not punch, but drill/mill/saw/route/form certainly. I can imagine a
system for hot or cold pressing monocoque plywood skins that was
heavily automated. I can't invision an equivilant system for forming
and riveting aluminum because of the floppyness of it. (technical terms
abound :-) I'm thinking along the lines of a modern plywood
manufacturing plant adapted to make airplanes. I guess you could say my
approach would be to design an airplane around a factory instead of the
of the factory around the airplane.

The companies that used to build wooden airplanes gave it up
long ago. I think the Bellanca Viking was among the last airplane to
use significant wood in it (in the wing). Is the Falco still in
production? How much does it retail for?
Aluminum and composites start to look better all the time, huh?

Dan

Composites yes. Aluminum no. The reason really comes down to skilled
labor. I would prefer the assembly to be as idiot-proof as possible,
(predicting a probable shortage of skilled labor). While composites are
not idiot proof, I suspect composites would take to automated
manufacturing better. Specifically I've been VERY interested in
filament winding as a means of making both wings and fueselages. I
haven't seen this approached in any homebuilts either, though I do
understand that some hobbyists have built filament winding systems for
other things, like rocket motors for example.

Both the Falco and the Barracuda are beutious! From a hand-built
perspective their labor requirements are _huge_. But the variation of
techniques and materials is probably fairly low compared to other types
of construction. For a robot it is better to do one thing many times
than many things one time. So my hypothesis is that plywood aircraft
would benefit more from heavy automation than perhaps a Cessna or a
Maule would. The amount of data I have to support that position is
obviously lacking. But I would be interested in other opinions on the
matter.

-Matt