The Boy Mechanic Part 103

[Ill.u.s.tration: Fig. 11 to 15]

sufficiently stiff by uniting two sides with rivets. The ends at top are looped as shown, while the ends or b.u.t.ts at the base are opened out to make the feet. Rings are shaped on forms and are then riveted to the base cross-piece as ill.u.s.trated. Crosses are made to describe to central design and the plan is worked out quite readily with the different shapes.

The making of metal fire grate fronts has proven to be a very interesting and profitable occupation for boys in recent times.

Not long ago it was sufficient for the ingenious youth to turn out juvenile windmills, toy houses and various little knickknacks for amus.e.m.e.nt. The modern lad wants more than this. He desires to turn some of his product into cash. Therefore we present some of the patterns of fire grates which boys have made and can make again from sc.r.a.p iron, with few tools and devices, and find a ready market for the same as soon as they are made. Figure 11 is a sketch of a form of fire grate bar or front that is constructed with a series of circles of strip metal. The best way is to go to the hardware store or iron dealer's and buy a quant.i.ty of 1/4-in., 1/2-in., and 3/4-in. iron, about 1/8 to 3/16 in. thick. In fact 1/16-in. metal would do in many cases where the parts are worked out small in size. The 1/8-in. metal is very strong. Then after getting the supply of strip metal in stock, procure the usual type of metal worker's hammer, a cheap anvil, a 9-1b. vise, a cold chisel, a file or two, and a round piece of shaft iron, about 3 in. diameter and 2 to 3 ft. long. This piece of iron is represented at B, Fig. 12.

The iron is held in position by means of the straps of metal C, C, which are bent over the shaft tightly and grip the board base with set or lag screws as shown. The wooden base should be about 2 in.

thick and large enough to make a good support for the iron shaft.

The process of bending the rings in this way is as shown. The piece of strip iron is grasped at D. Then with the hammer the iron is gradually worked cold about the mandrel as at E until the perfect form is acquired. After the form is finished, the strip at the terminus of the ring is cut off. In order to get a steady base the wooden part may be bolted to a bench. In Fig. 13 is shown the method of clipping off the completed ring. The cold chisel is held upright, and by delivering several blows with the hammer upon the same, the point is caused to chip through the metal and release the ring. The shaft or mandrel is marked G. The cold chisel is indicated at I and the position where the hand grasps the strip is at H. The final operation in shaping the ring is by driving the protruding cut, lip down, to the common level of the opposite point, thus giving us the finished ring with the lips closed on the mandrel as at J, Fig. 14. These rings can be turned out in this way very speedily. The next operation involves the process of uniting the rings in the plan to shape the design. The design work is often worked out ahead and followed. Some become so proficient that they can develop a design as they proceed.

Figure 11 is a design of grate front used for various purposes in connection with grate fires. The series of rings are united by a rivet between each at the joining point. With thin metal the holes can be punched with an iron punch and hammer on an anvil where there is a hole to receive the point of the punch after the punch penetrates the metal. For the heavier forms of metal a drill is necessary. A metal drill and brace can be purchased very cheaply for this work. After drilling the holes, the parts are erected and the rivets inserted and headed up as each addition is made. Thus the series of rings are united and then the side pieces are similarly riveted. The points at the top are then worked out and joined on. These points are filed down to the necessary taper after the union is effected. The finis.h.i.+ng work involves smoothing rough places with a file and painting. Asphaltum makes a good black finish. Some of the best designs of grates are bronzed. Some are silvered. The different designs are finished as desired by customers.

Figure 15 is another design of grate in which the process of shaping the rings is like that in the first design. There are some half circles in this pattern and these are framed by shaping the same about the mandrel with the hammer. In order to get the shoulders close and the circle complete it is necessary to heat the metal. A c.o.ke fire can be made in a hole in the ground. Then procure a tin blowpipe and blow the flame against the metal at the point to be bent. This metal will become red hot very soon, and can be bent readily against the anvil and the circular form. Let the metal cool off on the ground after heating. Fig. 16 is another design

[Ill.u.s.tration: Fig. 16 to 20]

which can be wrought out. The middle adjustment is wire screen work which may be bought at a hardware store and set into the position shown. Fig. 17 shows a chipping off device useful in connection with this work. Metal chippers can be bought at any tool store. The chipper is placed in the jaws of the vise as at K, and secured there. The strip of metal in process of cutting is marked M. The hammer head is caused to strike the metal just over the cutting edge of the chipper. The quick, hard blow causes the cutting edge to penetrate far enough to sever the piece. Bending cold with a wooden form is done as in Fig. 18. The wooden form is marked P and is about 8 in. wide and 7 in. high, forming a one-sided oval shape. There is a pin R set into the base board of the oval form and the strip of metal for bending is grasped at S and the other end is inserted back of the pin R. By applying pressure, the strip of metal is bent to the form.

Figure 19 shows the hour-gla.s.s wood bending form, made by selecting a piece of hard wood block, about 6 in. square and boring through with an inch bit. Then the hole is shaped hour-gla.s.s like. The view is a sectional one. The block is placed in a vise and the strip for bending is inserted as at T.

The strip of metal is grasped at W and can be bent to various forms by exerting pressure. Fig. 20 is another type of fireplace front, constructed by uniting the shaped metal pieces. In fact an almost endless variety of designs can be wrought out after the start is once made. A good way to figure the price on the grate is to add up the costs of the parts and charge about 12 cents per hour for the work.

** How to Make a Water Wheel [374]

Considerable power can be developed with an overshot water wheel erected as in Fig. 1. This wheel is made with blocks of wood cut out in sections as indicated by the lines, so as to form the circle properly. The wheel can be

[Ill.u.s.tration: Overshot and Undershot Wheels]

about 24 in. in diameter to produce results and about 10 in. wide.

Get some tin cans and attach them around the wheel as shown. Bore the wheel center out and put on the grooved wood wheel, P, and a rope for driving, R. This rope runs to a wooden frame in the manner ill.u.s.trated. The water is carried in a sluice affair, N, to the fall, O, where the water dippers are struck by the volume and from 2 to 4 hp. will be produced with this size of wheel if there is sufficient flow of water. This power can be used for running two or three sewing machines, fans, fret-saws, and the like.

Another form of water wheel is shown in Fig. 2. This is driven by an underflow of current. This type of wheel can be made on lines similar to the other, only that the paddles are of wood and extend outward as shown. The wheel is supported in a bearing on the piece S. A belt, T, communicates the power to the wheel V and from here the power is carried to any desired point.

** How To Build An Imitation Street Car Line [374]

An imitation street car line may sound like a big undertaking, but, in fact, it is one of the easiest things a boy can construct, does not take much time and the expense is not great. A boy who lives on a farm can find many fine places to run such a line, and one in town can have a line between the house and the barn, if they are some distance apart.

Often all the boards and blocks required can be had for helping a carpenter clear away the rubbish around a new building. Wheels and parts of old bicycles, which can be used in so many ways, can be found at a junk shop at very low prices, wheels in good repair are not expensive. For the car for the street car line try to find a set of wheels having axles, but if you cannot find such, make shafts of hard wood, about 3 in. by 2-1/2 in. and by means of a jackknife turn, or shave down the ends to receive the hub bearings of the wheels. Fasten the wheel hubs securely over the ends of the wood with pins or little bolts, or if the wheel bearing is of such a nature that it revolves on its own journal, the journal can be fastened to the end of the wood piece. Each of the wheels should be provided with a sprocket; any chain sprocket of a bicycle may be used. Fasten these sprockets on the outside of the wheels as shown in Fig. 1. They can be set on over the bearing end and secured with a set screw, or the original key can be employed. It is best in cases like this to use the original parts. Make the floor of the car of pieces of boards placed on the axles and nailed, screwed or bolted, as shown at A. To erect the frame, place uprights, C C C C, in position as shown, fastening the ends to the base-boards and making

[Ill.u.s.tration: Fig. 3]

the roof line as at B, then put in the cross-pieces, G G. Seats, E E, are simply boxes. The drive of the car is effected by using the driving sprockets, D D, fitted to the crosspieces, G G, with the original bearings. The parts are thereby secured to the car and the chain placed on.

Key the cranks for turning to the upper sprocket's shaft and all is ready. If there are sprocket gears and cranks on either side, four boys may propel the car at one time. Considerable speed can be made on smooth roads, but it is the best amus.e.m.e.nt to run a car line on wooden tracks with a brake consisting of a piece of wooden shaft, pa.s.sing through a bore in the car floor, and fitted with a leather covered pad as at H. A spiral spring holds up the brake until pressure is applied by foot power, when the brake contacts with the wooden track and checks the car.

The track plan is ill.u.s.trated in Fig. 2. Get some boards and place them end for end on other pieces set as ties. The main boards or tracks, JJ, can be about 6 in. wide, to the edges of which nail strips about 3/4 in. wide and about the

[Ill.u.s.tration: Construction of Car]

same height. The ties, I I, can be almost any box boards. Wire nails are the best to use in putting the tracks together. The sprocket connection with the chain is shown in Fig. 3. This consists of the sprocket gear on the propelling shaft, and the crank. The pedals may be removed and a chisel handle, or any tool handle, subst.i.tuted, so as to afford means for turning the

[Ill.u.s.tration: Section of the Track]

crank by hand power. Great fun can be had with the road, and, furthermore, it can be made remunerative, as boys and girls can be given rides for a penny each.

** Clean Before Painting [375]

Apply a coat of raw starch water to a dirty wall before painting; this, when dry, may be brushed or wiped off.

** Varnish for Electric Terminals [375]

A good varnish for electric terminals is made of sealing wax dissolved in gasoline. To prevent brittleness add a little linseed oil.

** Measuring the Height of a Tree [376]

[Ill.u.s.tration: Method of Applying the Triangle Measure]

"Near the end of the season our boy announced the height of our tall maple tree to be 33 ft.

"'Why, how do you know?' was the general question.

"'Measured it.' "'How?'

"'Foot rule and yardstick.'

"'You didn't climb that tall tree?' his mother asked anxiously.

"'No'm; I found the length of the shadow and measured that.'

"'But the length of the shadow changes.'

"'Yes'm; but twice a day the shadows are just as long as the things themselves. I've been trying it all summer. I drove a stick into the ground, and when its shadow was just as long as the stick I knew that the shadow of the tree would be just as long as the tree, and that's 33 ft.'"

The above paragraph appeared in one of the daily papers which come to our office. The item was headed, "A Clever Boy." Now we do not know who this advertised boy was, but we knew quite as clever a boy, one who could have got the approximate height of the tree without waiting for the sun to s.h.i.+ne at a particular angle or to s.h.i.+ne at all for that matter. The way boy No. 2 went about the same problem was this: He got a stick and planted it in the ground and then cut it off just at the level of his eyes. Then he went out and took a look at the tree and made a rough estimate of the tree's height in his mind, and judging the same distance along the ground from the tree trunk, he planted his stick in the ground.

Then he lay down on his back with his feet against the standing stick and looked at the top of the tree over the stick.

If he found the top of stick and tree did not agree he tried a new position and kept at it until he could just see the tree top over the end of the upright stick. Then all he had to do was to measure along the ground to where his eye had been when lying down and that gave him the height of the tree.

'The point about this method is that the boy and stick made a right-angled triangle with boy for base, stick for perpendicular, both of the same length, and the "line of sight" the hypotenuse or long line of the triangle. When he got into the position which enabled him to just see the tree top over the top of the stick he again had a right-angled triangle with tree as perpendicular, his eye's distance away from the trunk, the base, and the line of sight the hypotenuse. He could measure the base line along the ground and knew it must equal the vertical height, and he could do this without reference to the sun. It was an ingenious application of the well known properties of a right-angled triangle. --Railway and Locomotive Engineer.

** White Putty to Black [376]

White putty on a black window frame can be made to harmonize by rubbing the fresh putty with a piece of cotton dipped in lampblack.