Need some tried and true baseline specs for aluminum main spar tubes through (hot-wire-cut-Rutan-style) foam wings. What gauge and diameter aluminum tube are folks using for that main spar?
And then the heavily-loaded lower rear wing that mounts to your attenuator or gearbox. What size here are people using to max out their stiffness/strength/weight ratio here?
I'm sure expensive carbon fiber tubes have been employed as well. Any info on perhaps using carbon tubes? (Also, forgot... is "Uni" the stiff one?)
And then, just because I'm curious... does anyone know what kind of load is that lower wing seeing as it carries the top wing's downforce as well as the small amount of its own?
Thanks for any help, as always.
Chris