This proves you can build really light with the current Guillow's wood. The specifications for an A-6 are: maximum 30 square inches of wing area, all outlines 1/16" square wood, a six inch prop with absolutely flat, 1/32" blades... no camber...no sanding round on the edges, six inch motor stick, the ribs may be 1/16" X 1/32", and a minimum weight of 1.2 grams. The O.F.F.C. had an A-6 contest in October. I really wasn't going to enter but I decided, "What the Heck, it doesn't take that long to build one of these things."
I looked at ones that the other guys were trying to dial in for the contest and tried to analyze the features of the best flying models. So, I drew one up going for the maximum wing area, a swept wing for stability, dihedral tips, a lifting stab with twin rudders, and a 45 degree prop. When I tried to trim it out at El Cariso on the Saturday before the contest. Boy! Did I get it wrong!
The prop was so far out of balance that the model looked palsied when flying. The prop did not give enough thrust even with 3/32" rubber behind it. and the pitch trim was way too sensitive probably because of too much elevator area. The boom was way too weak to handle that much tail surface.
With other, paying, projects on my table I decided to do a quick and dirty fix before the contest rather than build another one. (What did I say about how long it takes to build one?) I made it a twin boom configuration, which solved the weak boom problem, and a 30 degree prop to get a better climb.
At the contest, I had trouble tying knots in the small rubber and had some motors unwind while I was winding. This is very frustrating, to say the least. I ended up flying it on a loop of 1/16" rubber. The low pitch prop gave a good climb, but used up the motor too fast. It did not have a good glide because of the excess elevator area and the best flights I got were about 45 seconds. You weren't even on the board with under 2 minutes. I might have gotten away with it if the elevator had been flat.
After the contest, I put a 4" North Pacific prop on it and it was and entirely different animal. In this configuration it's a fun sport model, but it's not an A-6. With a little rework I think that this twin boom configuration has some potential, so I will continue to work on it when I have some time.