Evening Republican, Volume 19, Number 287, Rensselaer, Jasper County, 4 December 1915 — HANDICRAFT FOR BOYS AND GIRLS [ARTICLE+ILLUSTRATION]

HANDICRAFT FOR BOYS AND GIRLS

B y A. NEELY HALL and DOROTHY PERKINS

(Copyright, by A. Neely Halt)

MODEL AEROPLANE PROPELLERS ANO A MOTOR WINDER.

A pair of propellers must be of Mentical else, but opposites—rightband and left-hand; that is. the upper end ot the right-band propeller must be shaped to turn to the right, and that of the left-hand propeller to turn to the left, when viewing the mounted pair from the rear of the model. After preparing one propeller in the manner described below, make the

second one with blades turned in the opposite direction. Figures 1 to 7 show the seven steps In preparing a propeller. Let the “Figure" numbers also represent the “Step” numbers. First of all prepare a propeller “blank" of the dimensions shown in Step 1. This block should be of straight-grained white pine, and be planed up straight and true on all sides. Draw a line around the four faces of thfe block at the exact center of its length. Then on faces C and D.

lay off a distance of one-half inch on the center-line, measuring from the edge of face B, to provide for the thickness of the propeller-hub (Step 2), and from the point representing the end of this measurement draw diagonal lines to the upper left and upper right-hand corners (Step 2). Then with a saw cut away the portions above these lines, as shown in Step 3. Mark out the one-half-inch hub upon faces A and B of the block, and bore a small hole through the center for the propeller-shaft to run through (Step 3). Then draw diagonal lines from the ends of the hub center-line to all four corners (Step 4), and saw away the wood above and below these lines (Step 5). Step 6 consists in laying out the form of the propeller blade upon all four sides and ends of the block, and Step 7 is the final cutting and shaping of the blades. After finishing the cutting, place the propeller at its center upon the edge

of your knife, and if it does not balance perfectly cut away enough of the heavy end until it does. Smooth up the surfaces with emery-paper, then shellac them. The rubber-strand motors are wound 1,000 turns or more, for a flight. The pair must be wound an equal number of times. To simplify this winding, boys take a Dover egg-beater (Fig. 14). and cut off the ends of the wire loops, and the central pivot wires on which the loops turn. Then they bend the cutoff ends of the loops into hooks, punch the loop ends for the pivot wire ends to stick through (Fig. lb), and rivet these to keep the hooks Ip position. Figure Id shows how the bow ends of the rubber-strand motors are removed from the framework, and slipped on to the winder hooks, for