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General control line discussion => Open Forum => Topic started by: Ferenc Zámolyi on April 14, 2020, 09:21:49 AM
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Gentlemen, has anyone in this forum built a Dancing Girl bipe? I`m building one and need some advice.
The designer, Mr. Peter Miller, strongly advises building in a one degree negative incidence in the top wing, for the purpose of improved stability. What`s your experience regarding this matter? Have you any hands-on opinion on that?
The other question is about the rigging wires. Have you used them in your plane? Again, what`s your experience regarding that?
Thanks for any input
Ferenc
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I believe Bill Morrell just recently built one. You might do a search on here for that on here. I also think he did a build thread on Control Line Flying on facebook. I am pretty sure it was the Dancing Girl he was building.
Mike
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Thank you, Mike. I'll try to find it. Anyway, I hope someone will chime in with more information on the subject.
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I had a friend years ago that built several biplane stunters, even a even a Fokker triplane. He used that trick.
It makes some sense. If you try to get the wings exactly parallel you can't. The airstream doesn't fly perfectly straight over the plane no matter what you do. The incidence slightly unloads the upper wing so the wings fly slightly differently and one panel or the other doesn't change it's lift radically around neutral.
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I do that on RC bipes as well - slight negative incidence in the top wing.
I think it's similar to toe-in on the main landing gear on your tail-dragger. If the plane yaws left (on the ground), the right wheel sees more drag/friction on the ground (than the left wheel) and tends to correct, pulling the nose back to the right.
In flight, I suppose, if the plane pitches up, the lower wing sees more induced drag than the upper, and tends to counter the pitch.
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Good points, Phil and Keith. Thank you for your comments. I think I'll go with the negative incidence in the upper wing.