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.

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.