butlern

My Feedback: (15)

I have a friend who recently cobbled together his very own version of the Wright Flyer... It's essentially two, stacked Sig LT-40 wings (with ailerons, naturally), as well as the dual canard in the front and the dual rudders in the rear. Powered by YS 53 mounted centrally between the two wings. Sounds, iffy, right? Indeed is was...

His first attempted flight resulted in a gentle climb (about 2-3 feet) followed by violent pitch straight up, stall, crunch.

When I talked to him about it afterwards we both agreed that either the canards had too much throw (I suspect they're pretty sensitive) and the balance was way off... He balanced his contraption on the main spar of the bottom LT-40 wing (where it should balance were it attached to an LT-40 fuselage). Since there's no tail-plane in the back of this model, I argued that the balance should be at (or even in front of) the leading edge. But, we have no plans and no reference materials... except this forum...

So, my question is... where should the Wright Flyer balance? Anyone ever sucessfully modeled an R/C version?

Thanks in advance

Noah

crasherboy

My thoughts. From what you said about the voilent climb,etc, it should balance much forward of where he had it . And I have the feeling that the canards should not have a lot of throw. Try a little less power to ,to start with. That would be the way I would look at this.

BMatthews

It's a canard so your idea of balancing in front of the normal CG location is the right one.

The longer the wing to canard moment arm and the larger the canard area the more forward the CG should be. But definetly balancing on the spar is WAYYYYYY too far back.

At a guess and assuming that he made the canard too small just like the Wrights I'd say balancing at around 5% to 10% would be an excellent starting point.

A quick way to check this would be to make a simple little all sheet balsa glider. Make it to scale with about a 12 inch span from 1/16 sheet. Don't worry about an airfoil. Just leave them flat or sand in a bit of leading and trailing edge taper and call it good. Set the canard about 2 to 3 degrees positive compared to the wings. A simple stick of 1/4 square will do nicely for the fuselage and use a pylon of more 1/16 sheet for the wing spacer. By now you should be getting the idea.

Then go test fly it over some tallish grass and play with the balance point until it glides smoothly. Measure where it balances level when you hold it up by the top wing. Put the big one's balance point at the same % location. It should be stable or near stable at that point.

guerjac

I fly a Wright Flyer 1903 (40" span) without any problem. the CG is exactly on the leading edge of the main wing.

Jacques

butlern

My Feedback: (15)

Thank you all for the replies. I have forwarded these recommendations to the builder. I will post again with the results, good or bad!

Regards,

Noah

Jim Thomerson

I just got an old magazine which has plans for several rubber powered competiton model canards. All have the CG well in front of the wing. On the other hand, the canard moment is considerably longer than on the Wright Flier.

buzzard bait

The Wrights lengthened their airplane and increased the stab area as they developed it, and by the end of 1905 it was much longer and much more stable than it was in 1903, and even then it hunted up and down in flight, which can be seen in early movies. Jim