The Boys' Book of Model Aeroplanes / How to Build and Fly Them: With the Story of the Evolution of the Flying Machine

by Francis A. Collins

A single stick about one half an inch in diameter may be used for the backbone. It will be found an excellent plan to attach the planes lightly to the main frame so that they may be adjusted before fixing them finally in position. Place them in the position shown in the accompanying photograph, and move them up and down until the flights are all that you expect, when they may be fastened for good and all. The bracing of this model is excellent and may be safely imitated. It enables one to tune up either plane and fix them rigidly in position. The propeller is very properly placed forward although it appears to be rather small. It is unnecessary to bother with any vertical rudder for this model since the curve of the front plane insures a reasonably straight flight.

A popular French model which may be easily imitated consists of curved planes both front and rear ([Plate 3]). The curve of the planes is too complicated to be carried out in wood, but may be readily formed by bending a stiff wire to the desired shape. The front plane should be about twelve inches in width and four inches in depth. The rear should be about half this size and of the same form. The planes may be readily mounted on a small dowel stick. A small propeller and a motor a foot in length will answer. A small semi-circular fin should be set below the rear plane to act as rudder. First cover the frames with a stiff paper and after you have succeeded in adjusting it, this may be replaced by cloth. The model will not fly far, or very steadily, but it is interesting to practice with. The balance of the model is open to criticism; for the center of gravity appears to be too far forward.

PLATE II.

A Model Aëroplane Worth Imitating.

The simplest of all models to build, and not the least interesting, is the small paper monoplane ([Plate 4]). The planes which are slightly curved are formed of a stiff card which will hold its shape when bent into position. These may be attached to the main stick by inserting an edge into a groove in the stick and glueing in place. It is not well to construct these more than six inches in width over all.

One of the simplest monoplanes to construct is formed of a broad rectangular forward plane with a fan-shaped stability-plane at the rear ([Plate 5]). This is a French model which is said to have flown long distances; that is to say, 300 feet or more. It has several very interesting features. In the first place the combined area of its planes is doubtless greater than that of any other model here described. The vertical rudder which looks very shipshape and effective is very easy to build and the frame illustrates several new principles.

The frame or motor-base may be made of heavy dowel sticks or light lath as indicated in the photograph. It will be found simpler to avoid tapering the frame at the rear by merely constructing a stout rectangular base with a length two and one half times its width. The forward plane is slightly bowed or flexed. It will be found a good plan to construct the frame for the base and then bow a light strip at either end against the edge. By fastening the covering to these curved strips a smooth curved surface may be obtained.

The rear stability-plane may be stretched over a fan-shaped frame of strips or lath which is in turn fastened to the motor-base. Another plan is to attach the front and rear edges of the plane, the rear one being slightly longer, and stretch the covering over these leaving the sides free as in the photograph of the accompanying model. The vertical rudder is very simple, consisting of a piece of dowel stick sunk in the rear frame to which a rectangular piece of cloth is attached the front corner being pulled taut.

The spread of the planes appears to be considerably greater than needs be. Since the front plane is flexed it may be reduced one third or even one half in depth without reducing its lifting quality; although in this case it should be placed nearer the stability plane. This reduction would, of course, make an important saving in the weight of the craft. So large a model calls for two propellers which will prove more effective at the front rather than the rear of the machine. It might be well to carry the motors further back than has been done in this model thus gaining additional power.