Is this a reflex aerofoil?

[andrew b]

Hi all.

I have come here for some advice on a model I have started building. Its a "Dracon" designed by Dave Boddington and there a few anomolies on the plan that escape me or at least aren't so clear / explained.

As you can see from the drawing it's a canard 1/2A machine and on the plan it shows the outer part of the trailing edges of the wings (the last 3" or so) the trailing edge is "packed" up by 1/8" and my question is..... Where is the aileron neutral point. are they also packed "up" by 1/8" or are they level with the datum line? :confused: The plan or instruction doesn't make this clear. The only time I have seen reflex wing sections was on a tail-less glider.
Could someone advise me please?

http://i61.photobucket.com/albums/h51/andrewinpopayan/Draconplan1.jpg
http://i61.photobucket.com/albums/h51/andrewinpopayan/Draconplan2.jpg

[Ollie]

No, I would not call it a reflex airfoil for every condition. The aileron and elevator change the airfoil when the controls go up with reflex and when the aileron and elevator goes down the airfoil is not reflexed. You could change the air speed with the airfoil plus or minus reflex. You could change the pitch attitude for climb or dive with the airfoil plus or minus reflex.

[Sparky Paul]

That's a Jedelesky airfoil.
Very easy to construct.
The aileron trim point will need to be determined by flying it.
It's possible that fixing the surface on the canard so it can't move, the ailerons can become elevons.

[BMatthews]

It's adding a little reflex but no where near enough to be self stabalizing. More likely it's just to add a touch of washout to the tips.

[andrew b]

That seems like the answer Mr Mathews,, it just that the reaon is not made clear n the plans. I MAY do a "little" modification to the original and fit two micro servos to the ailerons instead of the single servo in the original. I could then mix either flaperons or elevons on the 5th channel and find a good neutral position. Does that sound feasable?

[histarter]

It's adding a little reflex but no where near enough to be self stabalizing. More likely it's just to add a touch of washout to the tips.
I believe you got it BMatthews! That was my first guess also! :D