I'm scratching my head over this problem, so I thought I'd share it with you, not so much for sugestions as for sharing the fun of design. I've design warpwings for a ground effect craft. I showed it around and some of you rightly pointed out that the way the wings meet the water is wrong. WIG craft usually have anhedral wings that turn up at the end or have a sort of fin that goes up. The lowest point of the wing usually has a float on it. This same sort of float shows up hanging down from the wings of amphibious aircraft such as the Lake Buchaneer. I decided that I need to angle what I'm calling the pinion fans upward. This leads to a problem with the part that I call the wrist. Here is how my thought process has gone. In designing wings with movable part I had trouble making the hinges out of paper. They were coming out too floppy and fragile, so I have made the hinges out of strip styrene with wire as the hinge pins. The wing structure is make of two parallelograms with the stripstyren forming the leading and trailing edges. The fore to aft parts(formers) are paper laminated around the wire hingepins. Thread diagonally across the parallelograms opens and closes the wing. The angels of a triangle always add to 180 degrees. If you shorten one leg of the triangle(the rigging thread) the angles change and squews the parallelogram(wing sturcture) and the wing warps. Currently the pinion fan rotates on a hinge wire that goes through a plastic laminated part(the wrist). This part then attaches by two hinge to the last wing former. The place where the part has projections to fit into the hinges is already prone to breakage. Angling the pinion fans upward puts a bend in this already weak part. So the puzzle is how to redesign this part so that it doesn't break. To make it more complicated the skin of the wing is nylon fabric that that is sewn closed over the end of the wing former. There is just enough room between the wrist and the former to get a needle through and sew the skin. If I make the wrist out of mattboard instead of plastic and glue it to the former instead of wiring it to the hinge it wouldn't have the weak projections but I'd also have to change how the skin attaches. Design seems to get the most difficult in attaching different kinds of materials together.