zoomzoooie

All drawings I have seen do not show the droop in the trailing edge. It's funny though if you look at the lower wing it looks like the trailing edge is curved across from the root to the tip, specially in the shot from the rear. But it's not. I am wondering though where is the sources for the drawings that are out there?

I wondered the same about the flexibility of the rear part of the wing too. With such a thin wing I would also think that there would be some flexing, although I think the covering would inhibit flexing. If too much flexing went on the covering would most likely tear on the bottom of the wing. The Albatros types had an even thinner wing airfoil and I don't think their wings had any flex. One thing I came across was early Fokker D7 top wing center section trailing edges were weak and broke away in flight. This might have had to do with poor craftsmanship though. I think if they would have to have made the rear of the Halb wing strong enough to keep this from happening, most flexing would not be present.

I agree with the early experimentation in design. I think the forward positioning of rear spars had to do with the thin airfoil. The spars would had to have been made thick enough to take the stress. Any thinner and they would not be able to so had to be postioned forward. I think what they learned back then is more than we give them credit for. For example the use of full flying surfaces were more effective at slow speeds. Many of the design features do have a purpose and aesthetics is probably one of them. It's just hard to figure some of the features out without actually building them. The art of wood working engineering and techniques they used is mostly lost today.

I'm almost finished making templates for the wing ribs. The first set I made were too thin of an airfoil so I had to start again. I decided to go with the airfoil from The Pipe's drawings. For thin airfoil ribs, one way to make them strong is to laminate two balsa sheets together and cut the ribs. I did this with 1/32" hard balsa to make 1/16" and it was extremely strong even with 1/4" rib height after the rear spar. Once I get my ribs cut and start fitting them to the spars I will see how well this will work. My tip bows will have the correct shape as in the pics and will be laminated too. I'll try to build the washout ing the wing but with solid spars it might not stay so it might have to be kept with the covering. I'll post the results. In a large model the spars can be built with a top and bottom and sheer webbed, that should keep the washout.

Covering will be the hardest to do because you have an under cambered wing and you have to start the covering on the bottom. I'll have to make jigs to set the wing in upside down to keep the alignment while covering the bottom.

I wish I could get pics up but they will have to wait.
I'm really anxious to see how it will fly though.

Yes it's a mystery all right. [:-]

ZZ