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Question about flaps and flaperons

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Old 10-04-2006, 02:06 PM
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gilbertfh
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Default Question about flaps and flaperons

I have built a couple of aircraft now one out of coroplast and one kitbashed from a crashed decathlon. Now when I apply flaperons on the coroplast spad the aircraft dives like I gave down elevator. When I give flaperon with the former decathlon I gain altitude. I have been able to mix the flap with elevator in both instances but I would like to know why it does this so maybe I can design a model that does neither.
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Old 10-04-2006, 02:39 PM
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jeff1127
 
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Default RE: Question about flaps and flaperons

You didn 't mention the wing incidence of either. It would seem you have a negative incidence on the coroplast.


I'm sure someone else knows better. The above is just my opinion.
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Old 10-04-2006, 03:49 PM
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firstplaceaviator
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Default RE: Question about flaps and flaperons

Every aircraft I have ever flown (that has flaps), when the flaps are deployed, the nose goes down.
As far as designing a model that will not do this, it is not likely.
You are changing the airfoil and the angle of attack of the wing, therefore the trim is going to change.
You cannot change the wing configuration without changing the tail configuration.
Even with 0/0 incidence, you will have the same trim problem. It is unavoidable.

On the Decathaolon, when you trim it to fly straight, is the elevator in line with the horizontal stab?

Doug
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Old 10-04-2006, 05:08 PM
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Default RE: Question about flaps and flaperons

All the planes I have flown including my b-24 when I lower the flaps the nose goes up as a result of the extra lift generated.The plane slows down also as a result of the increased drag.When I used to fly control line stunt we had the flaps coupled to the elevator so that down flap and up elevator would result in a 90 degree pull up for square corners,up flaps and down elevator would also do the 90 degree corner straight down hence the square loop.Flaps are even used on take off to shorten the take off run and provide a steep climb after take off
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