# Toy-Making at Home: How to Make a Hundred Toys from Odds and Ends/A Sand-power Engine

Layout 2
​Engines of all sorts are always fascinating to boys and girls, and later on we shall describe some excellent ones. At this point we wish to describe what is possibly one of the simplest forms of engine known, and certainly one of the earliest. It is the engine driven by a flanged wheel, which itself is made to turn by the weight of something falling on the flanges. The commonest form of this wheel is the water wheel, where the weight of the water falling on the wheel causes the revolution.
As water is generally a “messy” thing to operate with, especially on such a contrivance as this, we have substituted something else.
For the working of very light toys, sand provides an alternative motive power. If a flanged wheel be made after the fashion of a water wheel, and a steady stream of sand allowed to descend on to the flanges, then the wheel will rotate as long as the supply of sand lasts, and the power may be transmitted by pulley wheels for the working of some simple mechanism.
Fig. 76 shows
A Sand-power Engine.—The large driving wheel consists of two circles of thick cardboard, each about 6 in. across, firmly glued together. These two circles are bevelled, and ​fixed facing inwards, so that a groove is left in which the power band can run.
Through the centre of the driving wheel thus fashioned a piece of dowelling or old lead pencil is fixed, projecting ¼ in. on one side, and about 1½ in. on the other. Nails are driven
Fig. 76.
in the two ends of this axle, and the wheel is suspended between supports, glued and screwed firmly to a base board.
The flanged sand wheel is next constructed. For this, four oblong pieces of cardboard, 1¼ in. wide and about 2 in. long, are cut out. A line is scratched along each of these about ½ in. from the end, and the cardboard bent so as to form a ​scoop to hold the sand for an instant. These four flanges are then glued to the axle, and the side of the driving wheel. If the sand wheel so made is not sufficiently firm, then another small cardboard circle can be glued to the flanges, on the side remote from the driving wheel: this will strengthen the wheel and in no way interfere with the running.
All that is necessary now is to erect some sort of sand supply: for this a large canister will do. A tiny hole must be punched in the bottom of the tin, and a revolving trap made
Fig. 77.
with another piece of tin. This is simple enough: all you need to do is cut a piece of tin about ¾ in. long and ½ in. wide, and punch a hole in one end. This pierced tin should then be placed so that the unbroken end of the slip covers the supply hole. A forked rivet should then be passed through the hole in the slip and through the bottom of the canister and fixed in place (Fig. 77); the trap can then be made to revolve, and the sand supply started or stopped at will. The canister should be placed above the wheel so that a thin stream falls on the flanges and turns the wheel.
​If a string be now passed round the outside edge of the driving wheel, the mechanism can be harnessed to any toy and the motive power supplied. For instance, the contrivance can be erected on a flat hull similar to that shown in Fig. 83, page 70; and the power band, passing through a hole in the centre of the hull, can be connected with the propeller by means of a rod (in place of the elastic). The resultant machine, though not highly efficient, is yet quite attractive.