I just built this little RC delta from two sheets of 3/16" thick foamboard from Dollar Tree ($1.00 per 20"x30" sheet) held together with hot glue. I patterned it after one I saw on flitetest.com. It has double thickness on the front 40% of the wing, forming a Kline-Fogelman stepped airfoil of sorts. It uses a motor, speed control, radio, and other stuff I had laying around. It weighs about 10 ounces, and spans 28". It uses elevon control, where the control surfaces on the trailing edge of the wing can move in opposite directions for ailerons, or together for elevators. It should be fast and fun, and my investment was all of $2.00!