How It Flies; or, The Conquest of the Air / The Story of Man's Endeavors to Fly and of the Inventions by Which He Has Succeeded

by Richard Ferris

A, B, blank from which propeller is shaped; P, P, pencil lines at centre of bend; C, D, sections of blade at points opposite; E, G, propeller after twisting; H, view of propeller endwise, showing outward twist of tips; also shaft.

As the propeller is the most difficult part to make, it is best to begin with it. The flat blank is cut out of the whitewood, and subjected to the action of steam issuing from the spout of an actively boiling tea-kettle. The steam must be hot; mere vapor will not do the work. When the strip has become pliable, the shaping is done by slowly bending and twisting at the same time—perhaps “coaxing” would be the better word, for it must be done gently and with patience—and the steam must be playing on the wood all the time, first on one side of the strip, then on the other, at the point where the fibres are being bent. The utmost care should be taken to have the two blades bent exactly alike—although, of course, with a contrary twist, the one to the right and the other to the left, on each side of the centre. A lead-pencil line across each blade at exactly the same distance from the centre will serve to fix accurately the centre of the bend. If two blocks are made with slots cut at the angle of 1 inch rise to 2¼ inches base, and nailed to the top of the work bench just far enough apart to allow the tips of the screw to be slid into the slots, the drying in perfect shape will be facilitated. The centre may be held to a true upright by two other blocks, one on each side of the centre. Some strips of whitewood may be so rigid that the steam will not make them sufficiently supple. In this case it may be necessary to dip them bodily into the boiling water, or even to leave them immersed for a few minutes; afterward bending them in the hot steam. But a wetted stick requires longer to dry and set in the screw shape. When the propeller is thoroughly dry and set in proper form, it should be worked into the finished shape with the half-round file, according to the several sections shown beside the elevation for each part of the blade. The two strengthening piece’s are then to be glued on at the centre of the screw, and when thoroughly dry, worked down smoothly to shape. When all is dry and hard it should be smoothed with the finest emery cloth and given a coat of shellac varnish, which, in turn, may be rubbed to a polish with rotten stone and oil.

It may be remarked, in passing, that this is a crude method of making a propeller, and the result cannot be very good. It is given here because it is the easiest way, and the propeller will work. A much better way is described further on—and the better the propeller, the better any model will fly. But for a novice, no time will be lost in making this one, for the experience gained will enable the model-builder to do better work with the second one than he could do without it.

For the aeroplane body we get out a straight spar of spruce, ¼ inch square and 15½ inches long. At the front end of this—on the upper side—is to be glued a small triangular piece of wood to serve as a support for the forward or steering plane, tilting it up at the front edge at the angle represented by a rise of 1 in 8. This block should be shaped on its upper side to fit the curve of the under side of the steering-plane, which will be screwed to it.

The steering-plane is cut according to plan, out of 1/16 inch whitewood, planed down gradually to be at the ends about half that thickness. This plane is to be steamed and bent to a curve (fore and aft) as shown in the sectional view. The steam should play on the convex side of the bend while it is being shaped. To hold it in proper form until it is set, blocks with curved slots may be used, or it may be bound with thread to a moulding block of equal length formed to the proper curve. When thoroughly dry it is to be smoothed with the emery cloth, and a strip of tracing cloth—glossy face out—is to be glued across each end, to prevent breaking in case of a fall. It is then to be varnished with shellac, and polished, as directed for the propeller. Indeed, it should be said once for all that every part of the model should be as glossy as it is possible to make it without adding to the weight, and that all “entering edges” (those which push into and divide the air when in flight) should be as sharp as is practicable with the material used.

The steering-plane is to be fastened in place by a single screw long enough to pierce the plane and the supporting block, and enter the spar. The hole for this screw (as for all screws used) should be drilled carefully, to avoid the least splitting of the wood, and just large enough to have the screw “bite” without forcing its way in. This screw which holds the plane is to be screwed “home” but not too tight, so that in case the flying model should strike upon it in falling, the slender plane will swivel, and not break. It will be noticed that while this screw passes through the centre of the plane sideways, it is nearer to the forward edge than to the rear edge.

If the work has been accurate, the plane will balance if the spar is supported—upon the finger, perhaps, as that is sensitive to any tendency to tipping. If either wing is too heavy, restore the balance by filing a little from the tip of that wing.

The main planes are next to be made. The lower deck of the biplane is of the 1/16 inch whitewood, and the upper one is of the glazed paper upon a skeleton framework of wood. The upright walls are of paper. The wooden deck is to be bent into the proper curve with the aid of steam, and when dry and set in form is to be finished and polished. The frame for the upper deck is made of the thin whitewood, and is held to its position by two diagonal struts of whitewood bent at the ends with steam, and two straight upright struts or posts. It is better to bend all cross-pieces into the curve of the plane with steam, but they may be worked into the curve on the top side with plane and file, and left flat on the lower side. The drawings show full details of the construction, drawn accurately to scale.

It is best to glue all joints, and in addition to insert tiny screws, where shown in the plans, at the time of gluing.