Fig. 89.—The Finished Biplane
Much depends on the way a model is launched. The proper way is to hold it by the propellers, with the thumb and forefinger along the main sticks, taking care not to bend the propeller hooks; then hold at about the angle shown in the photograph ([Fig. 90]). and launch as near as possible with the wind.
Fig. 90.—Launching the Model
It is necessary when flying in windy weather to launch the machine high and smartly, as the wind has a tendency to beat it to the ground. Both propellers must be released at exactly the same time. It should be carefully watched while it is flying, and if it persists in turning, say to the right, the fault will probably be that the left propeller is more effective, or the planes on the left side of the machine are elevated more. For straight flights it is most important that all the planes should be in perfect alignment; but to succeed in making a twin-propelled model fly perfectly straight is largely a matter of perfect construction.
The model can be steered by means of the elevator (looking at the machine from the propeller end); if the elevator is lowered on the left side it will fly round to the left, and vice versa. The adjustment necessary to effect this can be accomplished by means of the slot in one of the elevator uprights.
CHAPTER IX
Winders for Elastic Motors
To a model aeroplane enthusiast a winder is an enormous acquisition. The converted egg-beater type of winder, so much in evidence, leaves much to be desired, the chief fault being that the bearing spindles wear so quickly, apart from the fact that they are awkward to manipulate single-handed. A second person is generally required to support the model.
The winder here illustrated bears the distinct advantage that one person can wind, keep the model in alignment with, and forced into, the chuck simultaneously. The construction and general details will be fairly obvious from the accompanying illustrations, so that it will only be necessary to give a brief description.
It consists of an ash stump, 13 in. by 1 in. by 1 in., tapered at one end, as in [Fig. 91], to facilitate its being forced into the ground. A gear and pinion ([see Fig. 91]), which may be requisitioned from some of the cheaper type of clockworks, are mounted at the top end of the stump in a casting of No. 18 s.w.g. brass, which is secured to the ash by means of two round-headed screws ([see Fig. 94]). It will be found that for general purposes a gear ratio of six to one will be most suitable. Thus the pinion may have ten teeth and the gear sixty. The handle should be bent to shape after being passed through the stump. Copper ferrules are used on the spindles to keep the gears central between the casing, as shown in [Fig. 93], and should allow a little play to ensure easy rotation. The pinion spindle must be flattened out after the gearing is put together, and the hardwood chuck then driven on. A glance at [Fig. 92] will show clearly what is meant. The slot in the chuck should be made sufficiently large to take a carved propeller.