ORIGINAL: robin judd
Thank you for your ideas and comments. Thanks also for the South African greetings too!
You're welcome, Robin. I learn so much about modeling from this site, that I am always glad when I can also contribute a bit. Even more so when it is to help out a fellow South African
I like your thought that the front canard may have stalled in the final dives. It makes sense to put more nose weight in, but I am already carrying over a pound of lead in the canard already! I wonder if the forward struts will carry more. Maybe I need to beef them up.
When I look at the original prototype of 1909, I doubt whether it's CG was more forward than perhaps 50% - on the grounds that the Engine weighed about 75kg, which must be nearly the same as the pilot - and the canard looks no heavier than the stabilizers.
But then, the 1909 pilot had the advantage of being able to feel things developing before they happened, whereas we RC guys have to wait until we see the problem, which may be too late, so maybe I have no choice in the matter, but to make it more intrinsically stable than the original, by shifting that CG.
I can see your dilemma in having to carry that much weight in the canard. Also, you may be quite correct about the CG being further back than it should be in the original. As someone else here posted, this was the time when those great pioneers were still just starting to understand flight, and at that time much of the focus was on lift, propulsion and control, with stability not always getting as much attention as it should have. As I mentioned in the earlier post, several of the airplanes of the Wrights were unstable, but due to other factors, including as you mention being able to feel things develop when you actually fly in it, they were quite flyable with some practice. If you built a RC model exactly like a Wright Flyer, including the CG, control actuation, etc, you would have a very tough time flying it. All the successful models of those airplanes that I know of, had certain subtle changes made to them to make them more flyable. The most common "improvement" is usually the use of a more reasonable CG location. Luckily the CG is not something you can see visually on the airplane, so it doesn't spoil the scale looks (unless of course you need external weight for balancing).
I need to read your reply a few more times because it contains a lot of thought and then I need to experiment again, but this time with perhaps a bit more understanding.
I apologize for the technical rambling. I can go a bit overboard sometimes[sm=spinnyeyes.gif]
I had one more thought about your canard stalling out - as I mentioned, once you move the CG forward you may have to trim the rear horizontal with a slight nose-down incidence. If you add a bit of extra nose-down on the rear horizontal, the canard will unload a little and not have to lift quite as much. It may help a bit in delaying the canard stall. However, try to make small changes at a time if possible. First try to get the CG right so you at least don't run into the oscillations.
Cheers,
Bennie