How about taking the last third of all the wing ribs in a standard symmetrical wing kit, and instead of sparring them together, put them on an aluminium tube "axle". Then near the TE of the wing, cut a groove through each of the last third of the ribs. Through this groove you slide a bent control-rod. As the rod rotates in the grooves, it causes the ribs to rotate on the axle, with the outermmost ribs moving the most. Cover the ribs with the above mentioned condoms, and voila, you have a tiperon.

gus