Indoor rubber powered model airplanes typically use a rubber motor made of a single loop of stripped rubber whose ends have been tied together with a pair of knots. In this video I show the process of tying two reverse overhand knots in the ends of a segment of Tan Super Sport (TSS) rubber and cinching them down to minimize waste and get close to a target weight, e.g., 2grams. This process is valuable in indoor duration flying events such as F1D, F1L, Limited Penny Plane, A6, as well as the Science Olympiad Wright Stuff and Flight events. It is not necessary to apply CA to the knots.