Ok first of all that guy in the you tube link is nuts. 1. Crossing plane of a spinning prop is asking to be chopped up. 2. no one holding the plane as you start it or at least something to secure it form taking off into you is again asking to be chopped up. 3. ONLY 2 Bands!!! Beginers, please use that video as a example of what to never do.

My avistar 12-14 bands. Then I got wise, Fiberglassed the center 6 inches of wing (0 degrees of dyhderal) and use nylon bolts to secure the wing down.