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Old Dec 19, 2012, 02:24 AM
MICROACES is offline
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Joined Sep 2012
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Quote:
Originally Posted by Pouncer View Post
Hey Deadbird,

Watching this with interest, was rooting for the B&V or the Lizzie but warming up to the Curtiss!

I think you'll be fine with regards to wing loading, the thing I'd watch out for is the wing incidence(s). On a plane with staggered wings you absolutly want the frontmost one (the top one in this case) to stall first so that the nose drops and the plane recovers. If the contrary is true you'll have a model that behaves capriciously at both low speeds and high G maneuvers.

I'd start with a simple chuck glider of the Curtiss, with zero incidence on the lower wing and stabilizer, and adjustable incidence on the top wing.
With this setup you'll in fact be closer to a high wing monoplane that has a second wing producing little to no lift along for the ride. The COG is set accordingly, about 1/3 from the leading edge of the top wing, that is to say quite a bit forwards of what you'd expect.

This of course is just a starting point, but it will allow you to gauge how much incidence you need on the upper wing to fly well, and how much effect the lower wing counteracts stabilizer input, and perhaps you'll find that the stab could benefit from a small increase in size.
The next step is to add incidence on the lower wing (less than the top wing!) and moving the COG rearwards. Followed by a lot of fiddling with wing incidences..
The nice things with a chuck glider like this is that it's quick to make, easy to adjust and you can ignore motor incidences, that bit comes later.
This is super useful stuff Pouncer. The relative difference of incidence in my plans between wings is pretty much 0 at the moment. I will experiment with them now to try and get a better overall performance from her as I hadn't even thought of the beneficial effects of a difference in incidence between wings. I'm glad I started this thread now! Thank you.

Jon
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