The propeller bearings are turned out of ¹⁄₃₂″ bronze tubing, the length of each bearing being ¹⁄₂″. Steel washers are slipped over the propeller shaft, between the bearing and propeller to insure smooth running. The propeller shafts are made from steel hatpins which are heated at both ends, one end of which is bent into a loop to receive the rubber strands, the other end being bent around the hub of the propeller to prevent the shaft from slipping during the unwinding of the rubbers. Two strips of brass, each ¹⁄₄″ × 2″, are bent around the one-half inch bearing and soldered. The brass strips are then glued and bound onto the ends of the propeller brace as shown in [diagram 15].
Rudy Funk speed model
Schober compressed air driven monoplane. McMahon compressed air driven tractor (right)
THE ALSON H. WHEELER WORLD RECORD MODEL
(TWIN PUSHER BIPLANE 143 SEC. DURATION RISING FROM THE GROUND)
Since the beginning of model flying very little attention has been paid to the model biplane. Practically all records are held by model aëroplanes of the monoplane type. With this fact in view, the record established by Mr. Wheeler with his Twin Pusher Biplane is extraordinary, in so far as it surpasses many of the monoplane records. This model is a very slow flyer, and has excellent gliding ability. At the time when this model flew and broke the world’s record, the greater portion of the flight consisted of a beautiful glide of 86 seconds’ duration, after the power gave out, making it possible for the model to remain in the air for a duration of 143 seconds.
The frame consists of two I-beams, each 48″ in length, running parallel, and spaced by cross pieces, each piece 11¹⁄₂″ long. The bearing blocks used made it possible for the propellers to clear by one-half inch. Two 12″ expanding pitch racing propellers are used and these are mounted on ball bearing shafts. The main upper plane has a span of 34″ with a chord of 5″, the lower plane being 26″ by 5″. The elevator consists of two planes, each measuring 14″ by 5″. Cork wheels are used, each being one inch in diameter. For motive power one-eighth inch flat rubber is used, this being coated with glycerine to prevent sticking.
