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.
By EDWARD SILJA
After making several different styles of water motors I found the one illustrated to be the most powerful as well as the simplest and most inexpensive to make. It can be constructed in the following manner: A disk, as shown in Fig. 1, cut from sheet iron or brass, 1/16 in. thick and 9 3/4 in. in diameter, constitutes the main part of the wheel. The circumference is divided into 24 equal parts, and a depth line marked which is 8 1/4 in. in diameter. Notches are cut to the depth line, similar to the teeth of a rip saw, one edge being on a line with the center of the wheel and the other running from the top of one tooth to the base of the preceding tooth.
A 1/4-in. hole is drilled in the center of the disk and the metal strengthened with a flange, placed on each side of the disk and fastened with screws or rivets. A 1/4-in. steel rod is used for the shaft.
The cups, or buckets, are shaped in a die which can be cast or built up of two pieces, as desired. Both of these dies are shown in Fig. 2. The one at A is made of two pieces riveted together.
If a foundry is near, a pattern can be made for a casting, as shown at B.
Ill: Fig. 1 Metal Disk with a Saw-Tooth Circumference That Constitutes the Main Body of the Wheel
The die is used in the manner shown in Fig. 3. A strip of galvanized metal is placed over the depressions in the die and a ball-peen hammer used to drive the metal into the die. Cups, or buckets, are thus formed which are soldered to the edge of the teeth on a line with the center of the disk, as shown in Fig. 4. As there are 24 notches in the disk, 24 cups will be necessary to fill them.
Ill: Fig 2 Two Ways of Making the Dies to Shape the Sheet-Metal Water Cups
Ill: The Sheet Metal is Placed on the Die and Then Hammered into Shape
The cups are made in pairs or in two sections, which is a better construction than the single cup. The water from the nozzle first strikes the center between the cups, then divides and produces a double force.
When this part of the work is finished it is well to balance the wheel, which can be done by filing off some of the metal on the heavy side or adding a little solder to the light side. This will be necessary to provide an easy-running wheel that will not cause any unnecessary wear on the bearings.
The housing for the wheel consists of two wood pieces, about 3/4-in. thick and cut to the shape shown in Fig. 5. Grooves are cut in one surface of each piece, to receive the edges of a strip of galvanized metal, as shown at A. The grooves are cut with a specially constructed saw, shown in Fig. 6. It consists of a piece of wood, 6 in. long, 1 1/2 in. wide and 1/2in. thick, the end being cut on an arc of a circle whose diameter is 10 in. A piece of a broken hacksaw blade is fastened with screws to the curved end. A nail is used as a center pivot, forming a 5-in. and a 5 3/4-in. radius to swing the saw on in cut- ting the groove. After inserting the strip of galvanized metal, A, Fig. 5, the sides are clamped together with bolts about 3 1/4 in. long.
Ill: Fig.4 The Water Cups are Fastened to the Teeth on the Metal Disk with Solder
Ill: The Housing for the Wheel with a Connection to Attach the Motor on an Ordinary Faucet
A piece of pipe, B, Fig. 5, having an opening 3/8-in. in diameter, is soldered onto the metal strip A. An ordinary garden-hose coupling, C, is soldered to the end of the pipe.
Ill: Fig.6 Construction of the Saw for Making the Groove to Receive the Metal Strip in the Sides
A bearing, D, shaped as shown, is fastened to one of the wood sides with screws, the wheel shaft is run into it, and the parts assembled. A wheel, either grooved or flat, 2 1/2 or 3 in. in diameter, is placed on the shaft. The hose coupling makes it easy to connect the motor directly to the water faucet.