What You Should Know About Balsa
BALSA....how different our beloved hobby-sport would be without it! Can you imagine cutting wing ribs from pine? We tend to think of balsa and model aircraft as natural companions. But it wasn't always that way. In sport model aviation's earliest days-around 1910-balsa was not used. Models were build of pine, spruce, cane, and bamboo, and were covered with varnished silk and even thin leather. By 1923, about half of the structure of a typical contest model had become balsa. As late as the mid-thirties, rounded wing tips and tail surfaces were made of bamboo as often as balsa, but by then balsa had become the predominant modeling structural material. Balsa's dominance in model aircraft structures is not surprising; it has the lowest density of any commercial structural wood in the world. But, it might surprise you to know that balsa is classified by botanists and the lumbering industry as a hardwood! The botanical classification of woods as either hardwoods or softwoods had nothing to do with the actual hardness or softness of the wood.
Free Flight: Duration
Electronic Timer, At Last!: The Seelig Multi-Function Timer has established itself as the way to control the complex timing functions associated with gas-power models used in international competition: auto-rudder actuation, auto-stabilizer actuation, engine cut-off, and dethermalizer actuation. Still, anything less than 100% reliability means at least the destruction of a model that took a 100 hours to build and tune, and perhaps a shot at the World Championship. With every kid in the block owning a digital electronic wristwatch, and with four-function calculators now selling for under $10, the question naturally arises: "Isn't there some way we could replace all this clockwork with an all-electronic thingamajig?"
The Fourth National Paper Airplane Championships
HELD IN FEBRUARY in the gymnasium of the San Jose City College in California, the pretentiously titled Fourth National Paper Airplane Championships attracted kids from five to 54 from a 100-mile wide area, and mail-in entrees from as far as Saudi Arabia! Sponsored by the J. C. Paper Company and the Milpitas City-School Recreation Department, this was the most recent of the three or four meets held each year that are given sufficient publicity to attract contestants from several cities. Interest in paper plane meets in the San Francisco Bay Area is increasing; other meets in the area may soon top this one in size, but they'll have to go some to think up a fancier name for their meet.
Free Flight: Duration
Twin Props: Ever had a hankerin' to build a rubber-power Twin Bonanza?...or a B-26? Awhile back Fulton Hungerford entered a Ford Trimotor in the Indoor Scale Rubber-Power event at the Nats. The wing-mounted props were driven by rubber motors that ran through the wing, driving the props through coil springs that served as flexible shafts. And it flew! In the early thirties, Mamco marketed a system for driving two wing-mounted props from two rubber motors in the fuselage. A gearbox in the rear of the fuselage, driven by the rubber motors, transmitted power to two music-wire shafts which were connected to the props. But the "gearbox" didn't use gears; it used cranks and connecting rods for the same purpose. So nothing is new.
U.S. Free Flight Championships
OVER THE three-day Memorial Day weekend, Taft, CA-self-proclaimed Free Flight Capital of the World-hosted the sixth running of the U.S. Free Flight Championships. The statistics alone rank this meet as the greatest regularly held free-flight meet in the world, second only to the U.S. Nats: An AAAA sanction, first ever for an all-free-flight meet; 35 events; 175 trophies, plus six championship awards; 301 contestants; 715 entries. However, participation in most events was equal to, or less than, that of previous years. Participation by Juniors has decreased markedly. The only events showing a marked increase were the Old-Timer events.
