I recently built a new set of nine-foot heavy lift wings for my Senior Telemaster that I use with a 32cc Ryobi gasser for glider towing duties. I wanted to incorporate fowler flaps in the wing construction to help slow the plane down during steep descents from altitude and to help with landing this 18 pound airplane. I was unable to find a suitable commercial hinge that was large enough for this wing so I built my own. I did not originate this idea, but rather copied it from the Internet.

I used Du-Bro 601 nylon control horns bolted together to form a hinge as shown in the photos. I then used a small 90 deg. control horn connected to the flap servo to operate the flap. Be careful to get a  small control horn and note that the servo direction becomes opposite since a push towards the flap lowers and extends the flaps.