J. Carson Press

The illustration shown here is that of a small flying machine, and presents a form of amusement that has seldom, if ever, been made the subject of experiment for boys. It is exceedingly simple, practical and inexpensive, and opens up a vista of enjoyment through the summer months that cannot fail of recognition, especially as there are several other types, not quite so simple, 'tis true, but equally well within the means of every owner of a penknife, and some constructive ability. Fig. 1 shows clearly the general outline and disposition of the wings, propellers, etc., and requires only a few general directions as to the measurements, and materials to make it plain to the reader.

A Small Flying Device 230

Before starting to work procure, if possible, one of those 3ft. bamboo pipe stems the tobacconists sell; cut from this the strips used in the frame, wing arm, etc. This wood is light and pliable and is the best for the purpose. If it cannot be had, use a light wood that will bend. The frame at a a is made by inserting the ends of two sticks each 9 in. long, 1/8 in. thick, into two half cubes of cork, fastening with glue. To make the half cubes, cut half a cork to get pieces about 1 in. in diameter and 1/2 in. thick. See Fig. 9. A short round stick b, 3 in. long, is fitted to a depth of 1/4 in. in one of the pieces of cork. The stick must have a hole through it, so it is best to use the stem of a corncob pipe.

The wing arms cccc are 9 in. long, 1/8 in. thick, tapering at the outer ends. Insert the thick ends in the k, giving them a slight upward pitch, making a wery obtuse V. Then, after the glue has set, tie a light cord to the tips and bend until they measure 3 in. from tip to frame; fasten cord to frame. The wings should not be in exact line with the frame, but should point slightly downward; the proper angle is obtained by tying the cord to the under side of the frame sticks.

The propellers d d are two-bladed. The blades are made similar to the wings. Cut four sticks 7 in. long and very thin; bend until they measure 6 in. from tip to root. Fasten with thread, allowing for i in. or so of the end to be pushed into the cork. Next take two corks the size of a dime and 1/4 in. thick; fit the blades in these at an angle of about 40°. Remember in this connection that, as the propellers revolve in opposite directions, the blades must also be reversed. See Fig. 4.

Then take two pieces of brass spring wire, one 2 in. long, the second 3 1/2 in. long, and fashion a hook on sne end of each. To these hooksare fastened the propellers and rubber. Pass the long hook through the cork and length of pipe stem, the short through the other end. Place on each two small beads with a tiny washer between, push the free ends through the center of the propeller corks, taking care to see that the propellers, revolving in opposite directions, shall serve to lift the machine upward. Fasten the wire as shown at a in Fig. 3.

The small vertical rudder seen at b is made from spring wire 7 in. long, bent to a half circle by a cord running from two small hooks formed on each end.

The wings, propellers and rudder are covered with silk, or a good grade of linen paper might be best, as a smooth surface is an advantage. If silk is used, keep it spread out by pinning it to a board, then coat the sticks with glue and lay them on the silk, cut out afterwards; this will prevent wrinkles. The motive power is twisted rubber; you will require five small bauds, each 3 1/4 in. long, and 1/8 in. wide. Knot them together double and pass the free ends over one of the hooks, and where it is doubled over the other hook, making two lengths. If, after trial, this seems insufficient, or the machine does not fly very fast, add another length of thinner bands and twist the rubber by giving the propeller about 75 turns.

You will need something to hold the propellers from turning until ready to fly the machine. Make two small catches of the shape seen in Fig. 5; fasten these to the frame so that one end engages in the hook with the rubber. To the other end is fastened a light cord, which runs back to the end of the second catch By pulling this cord, both propellers are released at the same time. The machine should fly in a horizontal or slightly rising line; if it has a tendency to dip downward, reduce the angle of the back wings by twisting the cords around from the underside of the pipe stem to the side, and finally to the top if necessary.

The best way to commence is to first jot down the measurements of the different parts on a separate sheet of paper; first the frame rod s, then the wing arms, and so on. Then, with the directions in this concrete form, proceed to get out the different parts; the frame first, in the order of their presentation here. The corks used should be firm and sound, and all parts should be well glued together. Use a little judgement and your best workmanship, and the result will be highly gratifying.