Call up the PB100 Companion Guide for the first Fly Baby construction article, and go to page 40 ("Non-Cable Internal Bracing"):
http://www.bowersflybaby.com/PB100/Guide_1.pdf
There I discuss some alternate methods, and the advantages and drawbacks of each. It's aimed towards Fly Baby builders, but the same advice carries to other designs. As Frank mentioned, the alternates using solid tubes have an issue with trammelling (getting the orientation exactly right).
Dingdingdingdingding.... winner!
Pete didn't so much "engineer" the Fly Baby as he worked in details of successful aircraft of the sort of configuration he was planning. To quote Pete in EAA SPORT AVIATION (December 1962):
The wood construction was retained for simplicity and low cost and the aerodynamic layout was based on the two Story "Specials" then operating in Seattle in order to match their flying qualities, which were very definitely superior to others in the area.
The Storys were thoroughly conservative and conventional airplanes with a distinguished pedigree. Their immediate predecessor was George Beaugardus' "Little Gee Bee", which Tom Story of Portland, Oreg., had built just before World War II as a development of Les Long's famous Longster "Wimpy".
Note that the Fly Baby has engendered at least one ultralight "clone": The Ultrababy. It's a 75% scale Fly Baby designed for a half-VW.
It's all wood, though...not what you're looking for. Converting an existing design to an all-new material is not easy.
Here's something similar: I got into electronics as a teenager. This was in early in the "solid state" era, when transistors were replacing vacuum tubes. I did a lot of fiddling with them.
A friend came to me one day, with a small table-type radio. He wanted me to unplug the vacuum tubes and plug in transistors, instead, so he could make it portable. It was difficult to explain, in terms he'd understand, why that just couldn't be done.
You sometimes see the same thing in homebuilt aircraft. People think they can take a 3/4" square spruce longeron and replace it with a 3/4" aluminum tube. But even if the strength is the same,
the method used to attach components to each other is entirely different. And the interfaces are the key.
You mentioned extensive ground testing, and that's good. However, keep in mind that the testing should be of the aircraft, not just the wings. Keeping the wings on my Fly Baby depends on the bracing cables, turnbuckles, steel-tube compression struts, 1/8" steel anchors for the bracing wires, the wing spars, the 1/8" steel plates that attach the wings to fuselage bulkheads of stations 3 and 5 (which consist of spruce and plywood components of various sizes, the landing gear legs, and the main gear wheel axle.
About 40 years ago, the first Fly Baby in Finland underwent full Part 23 load testing (they didn't have an Experimental category in Finland). Here's how they did the positive G loading (from an English translation of the test report):
So the testing isn't all that simple. (If, for some reason, you want to read the whole report:
http://www.bowersflybaby.com/safety/...oad_Report.pdf)
I don't want to discourage you from designing your own airplane...after all, that's what EAA is all about. But if you're just looking for a plane to fly that fits your budget (like 99% of EAA homebuilt fans) you'd be better off with something off the shelf. The Aerodrome Eindekker sounds pretty good.
Ron "How about a nice game of chess" Wanttaja