This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
The materials used in the construction of this water wheel are such as the average amateur mechanic may pick up or secure from a junk pile. The drawings in Fig. 1 clearly show the way the wheel is built. The nozzle, Fig. 2, is made of pipe and fittings and is adjustable to concentrate the stream so as to get the full efficiency of the weight and velocity of the water. The cap on the end of the nipple is drilled to receive the pin point filed on the end of the 1/4-in. rod. The parts of this nozzle are a 1/2-in. tee, connected to the source of water supply; a plug, drilled to snugly fit the 1/4-in. rod, and fitted into one end of the straight part of the tee; and a 1/2-in. nipple of sufficient length to make the dimension shown in the sketch. The nipple has a long thread to receive two 1/2-in. locknuts, which clamp the nozzle to the sheet-metal covering, as shown in Fig. 1.
thick sheet-metal disk of the diameter given in Fig. 1. This disk is fastened to a 1/4-in. shaft, 6 in. long, with two collars, one on each side of the disk, both being riveted to the disk and pinned to the shaft. The bearings AA are made of 3/4-in. pipe, each 2 1/4 in. long. Long threads are cut on these to turn through the two 3/4-in. waste nuts BB, which provides a way to adjust the buckets centrally with the stream of water, and to take up any side motion. The pipe is babbitted and drilled for oil holes. The runner or wheel must be well balanced, as the speed will be from 2,000 to 2,500 revolutions per minute with ordinary city pressure. In balancing the wheel, instead of adding an extra weight, a part of the disk is filed out on one edge. The inclosing sides are made of wood - cypress preferred - having the dimensions given, and two 7/8by 1 1/2-in. pieces are attached to the bottom outside surfaces for mounting the wheel The curved part is covered with galvanized sheet metal.
The buckets, Fig. 3, are formed of some easily melted, but not too soft metal alloy which can be cast in plaster molds. They are attached with rivets to the circumference of a 1/16-in.
The drawing shows a wheel of small diameter, but having considerable power. Greater power may be obtained by increasing the size of the jet and the diameter of the wheel, but the use of too many buckets results in decrease of power. One bucket should be just entering the stream of water, when the working bucket is at a point at right angles to the stream. The water should divide equally exactly on the center of the bucket and get out of the way as soon as possible. Any stagnant water in the case, or dead water in the bucket, is detrimental to the power. A free exit for the water is made at the bottom of the case, as shown.
Ill: FIG.4 Metal Casing Instead of Wood
The construction of the case may be varied and, instead of wood, metal sides and frame may be used. Where the builder cares to make a more substantial wheel and has access to a foundry, the metal parts can be made as shown in Fig. 4. The parts are in this instance fastened together with machine screws. Patterns are made and taken to a foundry for the castings, which are then machined to have close fitting joints. - Contributed by R. H. Franklin, Unnatosa, Wis.