FIG. 51. Ball thrust bearing.
Ball bearing thrusts are by all means the most desirable, but not all models are large enough to accommodate their size and weight. Wherever it is possible, however, to use them it should be done. The increased amount of energy available for turning the propeller will make it possible to employ less rubber and so increase the number of turns and consequently the length of the flight.
FIG. 52. Hooks.
The hooks at either end of the rubber skein are apt to cut the rubber unless some precautions are taken to prevent it. This can be done by binding with cotton thread or slipping a piece of rubber tubing or aluminum over the hook as shown in Fig. 52.
CHAPTER VIII. BUILDING AND FLYING MODEL AEROPLANES.
The Blerioplane Flyer. (Plate II.)
The Blerioplane Flyer is of the simple monoplane type and is very easily constructed. It is a remarkable flyer when properly adjusted and will fly over one hundred and fifty feet.
The motor base is a piece of 3/16 dowel, 12 inches long. The edges of the planes are made of fine steel piano wire bent to the shape shown in Plate I. The planes are covered with silk which is carefully turned over at the edges, around the wires and fastened either by sewing or with bamboo varnish. The dimensions of the planes are clearly shown in the illustration.