Hi Keith. I think this WAS a serious model but I meant more about sizing it up for modern .61+ piped engines. The design is sound enough. For a ship this size I think I've made the split horns stiff enough. My concern about bending a straight horn for the tapered trailing edge is two-fold. The geometry puts the horn in something of a mechanical bind, putting wear and stress on hinges and horn. Also bending the horn here weakens the horn and might fracture the braze. The split horns at least get around these issues. I've done this a few times in previous years also with V tailed airplanes where a 30 degree angle made it nessessary. If the pushrod fork is stiff and close then I don't think there is much compromised.
I am not quite sure what you mean when you write about not wanting to bend the horn. Of course, a horn that is bent to match the flap forward sweep will bind and resist any deflection. (However, there is another solution here, but it sort of goes beyond the scope of this discussion.)
You would be surprised that with the relatively small amount of forward swept flaps that is shown in your photo that a single straight flap horn will work. Then, there is no compromise of excessive flexing from one flap to the other. I know it does not make sense because intuitively, one would think that as soon as the flaps start to deflect, there would be a bind that would restrict the movement of the flaps after a few degrees of deflection. That does not happen. Bill Werwage showed us that with his Juno that appears to have more forward sweep than your wing shows. My explanation for this single horn operation is that there is enough flex in the wood around the horn as well as flexing in the hinges and the wood holding the hinges that binding due to flap deflection does not start to occur until well beyond the 30 to 35 degrees maximum deflection of the flaps. I have no small amount of experience regarding this matter. I am just saying that for those who have not yet delved into this matter of swept forward flaps and dihedral, and top performance is desired, a split flap horn is not a desirable solution. Particularly when other solutions are available.
Yes, I am sure your model will be fully capable of flying a stunt pattern, and it will probably be totally satisfactory to you. It is just that better performance can be had with a properly installed single flap horn. It will avoid trim problems that will be encountered due to unequal flexing of the flaps during the maneuvers, particularly how the airplane responds in all of the eights and four leaf clover.
An alternative is to use "Lucky Boxes" which use only a single horn with the horn wire able to translate inside the flap. I have the elevators of a scale Swee' Pea Goodyear racer that has 40
o dihedral under each side of the stabilizer with a single horn, using Lucky Boxes. The operation is completely smooth and there is no "slop" or any excessive flexing of the elevators from one side to the other.
And before anyone jumps to conclusions, the famous multi-time National Champions referenced in my previous post is not Bill Werwage with his Juno referenced above.
Keith