Hello all, have a few questions for you guys. I am building a Goldberg Extra 300 for fun/3D style flying. First off, I know it is not designed to fly 3D as per the kit plans so I am moding it as I go... here is a list of things I doing to it and some things I have questions with reguarding the tail, any input on any of these subjects would be appreciated:

Wings-
I am extending the ailerons to be full length instead of ending 6-7" out from fuse sides and increasing the cord of them a bit. Obviously, separate servos for each as well.

Tail-
Here is where my questions mostly need addressing:
I want to redesign the tail so that the control surfaces are roughly 1:1 size ratio (cordwise anyways) with bigger counterbalances on the elevator and rudder. Going to put one servo on either side of the fuse under the horizontal stab for the elevator, one for each side (not joining them in the middle) and steepen the angle on the elevator inboard lines to allow for more rudder movement which will have the pull-pull system controlling it. Now, what is the feasability of converting the tail on this from flat to airfoils? I was brainstorming the idea of re-designing the tail and building all new stuff up to the same outside dimensions (surface area) as the stock tail but still move the hinging points in to increase the control surfaces. Is this a feasable idea that would work? If so, what airfoil do I use? Copy the wing? or a real Extra? or is there a rule of how to make these combinations work when using airfoils on tails of models?

Thanks for reading and any help/criticism of these ideas.
Brian

The full-scale Extra does have an airfoiled tail...
http://www.angelfire.com/indie/aerostuff/aerobats.htm
10% or so thick should be stiff enough.. if you make it thinner you might add bracing wires.

I know they have a symetrical airfoil on tail of a real one, but the kit for this model does not... 10% thickness should be sufficient I would think too, but what airfoil design? Or is it not as critical as it is with full size aircraft? Thanks for the thoughts Paul.

A typical tail would be an NACA 0010.. highpoint at 30%. That's the most important thing. Smooth curve from a rounded leading edge to the trailing edge.

Actually it is not all that critical on the full size airplanes either. What Paul says applies to a full size too. Maybe a little thinner for something like the F-15. I think we used a thin symmetrical pretty generic airfoil.

If'n the stab does not twist -- the airfoil is just fine --
Relative stab/elevator areas are sorta the same -- -As long as you can accurately move and control the elevator - make it as large as you want - but 50/50 is a easy setup -which works pretty well.