ModelTech Great Lakes Setup
djlyon,
I had put my Great Lakes projects on hold pending input from this group and my own research. I'm now ready to give it a try as soon as I finish a house project that got inserted in the que. Of all the biplane plans and examples I've encountered, none have required positive incidence in the upper wing. More often, if it is not set at zero, then it is set negative. Harry Higley, in his book on Bipes, even changed the Smith Miniplane from zero to minus one degree on the flat bottom upper wing to negate an "initial climbing tendency" for that model when built per instructions. Further, the Aeromaster bipe, highly regarded as a very good flier, has semi-symetrical wing profiles, similar to the Modeltech Great Lakes, and also calls for minus one degree on the upper wing. The rest of the plans/planes I investigated called for zero incidence.
I urge you to carefully check your upper wing profile. The example I have is most definately semi-symetrical, and is definately stamped "UP" on the wrong side of the top wing. I've never heard of a good reason to mount a semi-symetrical wing upside down on any airplane. I think Modeltech has some serious quality control issues. I never would have caught this if I had not been intent on making another top wing from the existing example. I am also going to change the the wing struts to four point attachment from the designed three. I don't want wing twist to add to any instability. Lastly, I am convinced that weight is an extremely important factor for this airplane. I will rework the empanage to take as much weight out of the tail as I can and mount all the radio gear as far forward as possible. I think I'll be able to get to this project in a couple weeks. I wish you luck with yours,
Blue skies,
Lloyd