Fig. 94A.—The Winder
Fig. 95.—An Egg Whisk
Fig. 95A.—Using Twin Winder
A Double Winder.—As each propeller of a twin-screw machine requires to be wound up 400 to 500 times, it is obviously necessary to use a geared-up winder. This can easily be constructed out of an ordinary egg-beater, and one converted into a very useful instrument is shown by [Fig. 94A]. The great advantage of using a winder of this type is that both propellers can be wound simultaneously. Figs. [95] and [95A] clearly show how the alteration is made; it is quite simple, and all the tools required are a three-cornered file, a drill, and a soldering bit. The egg-beater can be obtained for a few pence at any ironmonger’s. The two hooks at the nose of the machine are attached to the cross-pieces on the winder, and the rubber is wound in the same direction as the propellers revolve ([see Fig. 95A]). The winder shown is geared 5 to 1, so that 100 turns on the winder gives 500 turns on the propellers. Geared-up winders may be purchased fairly cheap.
CHAPTER X
Collapsible Monoplane
The difficulty of carrying a fairly large model to a convenient flying ground prevents many would-be makers taking a practical interest in model flying. The necessity of overcoming this difficulty has resulted in several excellent designs, one of the best being the monoplane designed and constructed by Mr. A. B. Clark, the secretary of the South-Eastern Model Aero Club. When this model monoplane was built the objects aimed at were extreme reliability and easy conveyance to and from the flying grounds situated some distance away.
The model is fitted with a chassis to enable it to start off good ground under its own power; but this starting-gear is so constructed that the whole model will pack up flat and make a convenient parcel. In fact, the complete model will easily go into a cardboard box measuring 2 ft. 10 in. by 1 ft. 2 in.
Referring to the accompanying illustrations, [Fig. 96] shows the plan view of the complete machine, [Fig. 97] a side view, and [Fig. 98] a front view. The body (fuselage) is made of two pieces of silver spruce, 3 ft. 6 in. long, ⅜ in. deep, and ³/₁₆ in. thick. These gradually taper towards each end, where they measure ¼ in. by ³/₁₆ in. Two distance pieces of bamboo are shaped to streamline form and placed at equal distances along the fuselage; the front piece is 2⅜ in., the other 2 in. These pieces should be pointed at the ends, and fit in a slot made in the side lengths, as indicated at A ([Fig. 99]), and then bound very tightly with glued narrow silk tape or ribbon, as indicated at B. This is the neatest and also the strongest method of making joints for model aeroplane frames. The ends of the two long lengths should be bound together with strong thread and carefully glued.