A Brief Guide to Building Lightweight and Sturdy Electric Model Airplanes

The growing popularity of electric flight calls for a completely new approach to design: a construction method that is lightweight yet as stable as possible. This guide is intended to help you successfully build and fly lightweight yet robust aerobatic and sport models. The construction method described here has been developed and refined through many models.

The airfoil thickness should not exceed 11–12% (flight time). The nose radius should be kept as sharp as possible (stall recovery). Apply two to three coats of finish varnish diluted 1:1. The use of film covering is generally not recommended (lacks stability). Please direct any questions to: H. Sommerauer, Waserstr. 21, 8053 Zurich

Lightweight wood that is not too soft should be used. Particular attention should be paid to ensuring that the grain runs straight and that the wood is not warped, especially in the case of pine spars and planking boards.

For most wood bonding applications, only a hard adhesive should be used (Uhu-Hart, Rudol-Hart, Stabilit-Dur). Two-component adhesives are used only for joints subject to high stress (engine mount, landing gear). Contact adhesive is the best choice for attaching the skin.

Cooling ports (cut-off aluminum tubing, Ø 10, angled) must be installed between the motor and the battery compartment. A safety clearance of approximately 5 mm must be maintained between the cells and the fuselage walls, and the rear end of the fuselage must be left open. Foam rubber must not be used when installing the system.