This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
By GEORGE F. MACE
The monoplane glider illustrated has better fore-and-aft stability than the biplane, is lighter in proportion to the supporting surface, simpler to build, and requires very little time to assemble or take apart. The material list is as follows:
FRAME 4 pieces of bamboo, 14 ft. long, tapering from 1 1/2 to
1 in. 8 pieces of spruce. 1/2 in. thick. 1 in. wide, and 3 ft. long 8 pieces of spruce. 1/2in. thick. 1 in. wide, and 2 ft long.
WINGS 4 main-wing bars, spruce. 3/4in. thick, 1 1/4in. wide and' 18 ft. long. 8 wing crosspieces. spruce. 3/4in. square, and 4 ft. long 38 wing ribs, poplar or spruce. 1/4 in. thick, 3/4in wide, and 64 in. long.
The first thing to do is to make the main frame which is composed of the four bamboo poles. The poles take the corners of a 2-ft. square space and are supported with the pieces of spruce that are 2 ft. and 3 ft. long, the shorter lengths running horizontally and the longer upright, so that each upright piece extends 1 ft. above the two upper poles. All joints should be fastened with 3/16 -in. stove bolts. The wire used to truss the glider is No. 16 gauge piano wire. The trussing is done in all directions, crossing the wires between the frame parts, except in the center or space between the four poles.
Ill: The Start of the Glide should be Made from the Top of a Hill, Then a Little Run will Carry the Airman Several Hundred Feet through the Air
The framework of the main wings is put together by bolting one of the crosspieces at each end of two wing bars, then another 4 ft. from each end, whereupon the wing bars are bolted to the main frame. The frame is then braced diagonally between these pieces. The ribs, spaced 1 ft. apart, are fastened to this frame with 1-in.
brads. The ribs are so bent that the highest part will be 5 or 6 in. above the horizontal. The bending must be uniform and is done when fastening them in place.
The material used to cover the wings and rudders is strong muslin. The cloth is first tacked to the front wing bar, then to the ribs, and sewed to a wire which is fastened between the ends of the ribs. Large brass-head tacks should be used through a strip of tape to fasten the cloth to the ribs. The rear wings are constructed in a similar manner. After the cloth is in place it is coated with starch or varnish.
Ill: Elevation Main Frame
Ill: Details of Tandem Monoplane Glider, Showing the Main Frame and Wing Construction, and the Manner of Placing the Crossed Bracing Wires Between the Parts and to the Wing Ends
The two vertical rectangular spaces in the main frame, just under the rear wings, are covered with cloth to act as a rudder. The upper and lower bracing wires for the wings are attached with snaps and rings so that the glider can be easily taken apart.
It is best not to use the glider in a wind greater than 30 miles an hour. It is started from the top of a hill in the usual manner. Glides can be made running from GO to several hundred feet.