Originally Posted by
abufletcher
The question that truly interests me is not how we can alter the design of our models to make them fly "better" but rather is it possible to use scale airfoils, scale incidences, scale dihedrals, scale empennage and still have a flyable model. I'm not necessarily talking about an "easy flyer" but one that flies pretty much like the original.
My SE5a is a good case in point. While it doesn't use a scale RAF airfoil, it does have a "scale-ish" airfoil. The wings are mounted at the same AoA as on the original (about 5 degrees) and use the same amount of dihedral (also about 5 degrees). The engine is mounted parallel with the main longerons as per the original. The main aerodynamic difference is that the stab on the model is at +3 to the center line, while the tail on the original (which was adjustable) was also level with the longerons. I'm hoping that now that I've gotten all the kinks straightened out my SE5a will fly as it was intended to fly. And if it can't...well...then I will have learned something.
I trust the original WWI designers and don't feel it's necessary to "re-design" models of WWI aircraft. I especially don't feel it's necessary (or desirable) to "improve" the design. Would we improve on the Mona Lisa? Sure there are inevitable differences. But I believe that the wonderful WWI scale models that have been built and flown in top competitions show that completely flying scale WWI models are indeed possible.
From what I have read (and been told) it should indeed be possible to build a model with scale fidelity that flies well.
Particularly in the case of WW1 subjects where the RAF-15 Airfoil for instance is apparently very tollerant of the issues caused by Mr Reynolds.
The incidences on your model all sound about right. But I would note that in some cases, the full sized prototype had the vertical Stab offset by about 4° to the right to counteract Engine/prop torque.
There is a factor that we modellers miss out on though regardless of the setup of a model. And that's the seat of the pants feel that told a pilot where to put the stick or rudder bar.
We rely on visual fed back which we then translate to what we think is happenning and what we can do to correct it. So it's only natural that we don't generally fly our models (unless we are very practiced and experienced) as smoothly as a pilot actually flying a full sized SE5a for instance might do.
The SE5a was known as a stable gun platform but with manueverability when needed...
I wonder if my Topfilght SE5a kit will have similar issues.
Cheers,
Hugh