When building RC drone with foam I think it is safe to say foam has become one of the most important materials for because of the ready availability and wide variety and use of low-cost electric power. It is much more economical for commercial suppliers of RC ARF aircraft to use foam than labor-intensive built-up balsa structures. In addition, the price for balsa wood, the traditional RC building material has continued to reach higher levels due to demand in other larger markets and limited supply.