Part 93 (1/2)

The following description is how a miniature windmill was made, which gave considerable power for its size, even in a light breeze. Its smaller parts, such as blades and pulleys, were constructed of 1-in. sugar pine on account of its softness.

The eight blades were made from pieces 1 by 1-1/2 by 12 in. Two opposite edges were cut away until the blade was about 1/8 in.

thick. Two inches

[Ill.u.s.tration: Details of Miniature Windmill Construction]

were left uncut at the hub end. They were then nailed to the circular face plate A, Fig. 1, which was 6 in. in diameter and 1 in. thick. The center of the hub was lengthened by the wooden disk, B, Fig. 1, which was nailed to the face plate. The shaft C, Fig. 1, was 1/4-in. iron rod, 2 ft. long, and turned in the bearings detailed in Fig. 2. J was a nut from a wagon bolt and was placed in the bearing to insure easy running. The bearing blocks were 3 in. wide, 1 in. thick and 3 in. high without the upper half. Both bearings were made in this manner.

The shaft C was keyed to the hub of the wheel, by the method shown in Fig. 3. A staple, K, held the shaft from revolving in the hub.

This method was also applied in keying the 5-in. pulley F, to the shaft, G, Fig. 1, which extended to the ground. The 2-1/2-in.

pulley, I, Fig. 1, was keyed to shaft C, as shown in Fig. 4. The wire L was put through the hole in the axle and the two ends curved so as to pa.s.s through the two holes in the pulley, after which they were given a final bend to keep the pulley in place.

The method by which the shaft C was kept from working forward is shown in Fig. 5. The washer M intervened between the bearing block and the wire N, which was pa.s.sed through the axle and then bent to prevent its falling out. Two washers were placed on shaft C, between the forward bearing and the hub of the wheel to lessen the friction.

The bed plate D, Fig. 1, was 2 ft. long, 3 in. wide and 1 in.

thick and was tapered from the rear bearing to the slot in which the fan E was nailed. This fan was made of 1/4-in. pine 18 by 12 in. and was cut the shape shown. The two small iron pulleys with screw bases, H, Fig. 1, were obtained for a small sum from a hardware dealer. Their diameter was 1-1/4 in. The belt which transferred the power from shaft C to shaft G was top string, with a section of rubber in it to take up slack. To prevent it from slipping on the two wooden pulleys a rubber band was placed in the grooves of each.

The point for the swivel bearing was determined by balancing the bed plate, with all parts in place, across the thin edge of a board. There a 1/4-in. hole was bored in which shaft G turned. To lessen the friction here, washers were placed under pulley F. The swivel bearing was made from two lids of baking powder cans. A section was cut out of one to permit its being enlarged enough to admit the other. The smaller one, 0, Fig. 6, was nailed top down with the sharp edge to the underside of the bed plate, so that the 1/4-in. hole for the shaft G was in the center. The other lid, G, was tacked, top down also, in the center of the board P, with bra.s.s headed furniture tacks, R, Fig. 6, which acted as a smooth surface for the other tin to revolve upon. Holes for shaft G were cut through both lids. Shaft G was but 1/4 in. in diameter, but to keep it from rubbing against the board P, a 1/2-in. hole was bored for it, through the latter.

The tower was made of four 1 by 1 in. strips, 25 ft. long. They converged from points on the ground forming an 8-ft. square to the board P at the top of the tower. This board was 12 in. square and the corners were notched to admit the strips as shown, Fig. 1.

Laths were nailed diagonally between the strips to strengthen the tower laterally. Each strip was screwed to a stake in the ground so that by disconnecting two of them the other two could be used as hinges and the tower could be tipped over and lowered to the ground, as, for instance, when the windmill needed oiling.

Bearings for the shaft G were placed 5 ft. apart in the tower. The power was put to various uses.

** How to Make a Telegraph Instrument and Buzzer [334]

The only expenditure necessary in constructing this telegraph instrument is the price of a dry cell, providing one has a few old materials on hand. Procure a block of wood about 6 in. long and 3 in. wide and take the coils out of an old electric bell. If you have no bell, one may be had at the dealers for a small sum.

Fasten these coils on the blocks at one end as in Fig. 1. Cut a piece of tin 2 in. long and 1/2 in. wide and bend it so the end of the tin

[Ill.u.s.tration: Home-Made Telegraph Instrurment]

when fastened to the block will come just above the core of the coil. Cut another piece of tin 3 in. long and bend it as shown at A, Fig. 2. Tack these two pieces of tin in front of the coils as shown in the ill.u.s.tration. This completes the receiver or sounder.

To make the key, cut out another piece of tin (X, Fig. 1) 4 in.

long and bend it as shown. Before tacking it to the board, cut off the head of a nail and drive it in the board at a point where the loose end of the tin will cover it. Then tack the key to the board and connect the wires of the battery as in Fig. 1. Now, move the coils back and forth until the click sounds just the way you wish and you are ready to begin on the Morse code.

When tired of this instrument, connect the wire from the coils to the key to point A and the one connected at the point under the key to B, leaving the other wire as it is. By adjusting the coils, the receiver will begin to vibrate rapidly, causing a buzzing sound.

--Contributed by John R. McConnell.

** How to Make a Water Bicycle [335]

Water bicycles afford fine sport, and, like many another device boys make, can be made of material often cast off by their people as rubbish. The principle material necessary for the construction of a water bicycle is oil barrels. Flour barrels will not do-they are not strong enough, nor can they be made perfectly airtight.

The grocer can furnish you with oil barrels at a very small cost, probably let you have them for making a few deliveries for him.

Three barrels are required for the water bicycle, although it can be made with but two. Figure 1 shows the method of arranging the barrels; after the manner of bicycle wheels.