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The
Boy Mechanic
MS’!
700 THINGS FOR BOYS TO DO
_ V /
HOW TO CONSTRUCT
WIRELESS OUTFITS, BOATS, CAMP EQUIPMENT, AERIAL GLIDERS, KITES, SELF-PROPELLED VEHICLES, ENGINES, MOTORS, ELECTRICAL APPARATUS, CAMERAS
AND
HUNDREDS OF OTHER THINGS WHICH DELIGHT EVERY BOY
WITH 800 ILLUSTRATIONS
Copyrighted, 1913, by H. H. WINDSOR
CHICAGO
POPULAR MECHANICS CO.
PUBLISHERS
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©Cl. A3 4 6032
A Model Steam Engine
The accompanying sketch illustrates a two-cylinder, single-acting, poppet- valve steam engine of simple construc¬ tion that can be made at home by the average boy having a few tools. The materials which make up the parts are such as can be easily shaped by hand and with hand tools, and are so de¬ signed that most of the parts can be cut from pieces of metal readily purchased at any local hardware store.
The only parts requiring any machine work are the pistons and the flywheel, which can be finished in a local machine shop at a reasonable cost. The pistons, if fitted closely to the bore of the cylin¬ ders, will require no rings or other packing, the cost of the machine work thus being reduced.
The entire engine, excepting the fly¬ wheel, shaft, valve cams, pistons and bracing rods connecting the upper and lower plates of the frame proper, is of brass, the parts named being of cast iron and bar steel.
The cylinders G are of seamless brass tubing, 1% in. outside diameter; the pistons H are ordinary 1-in. pipe caps, turned to a plug fit and ground into the cylinders with oil and emery. This op¬ eration also finishes the inside of the cylinders.
The upright rods, binding the top and bottom plates, are of steel rod, about % in. in diameter, threaded into the top plate and passing through holes in the bottom plate with hexagonal brass nuts beneath.
The valves C, and their seats B, bored with a countersink bit, are plainly shown. The valves are made by threading a copper washer, % in. in diameter, and screwing it on the end of the valve rod, then wiping on roughly a tapered mass of solder and grinding it into the seats with emery and oil.
The valve rods operate in guides, D, made of %- in. brass tubing, which passes through the top plate and into the heavy brass bar containing the valve seats and steam passages into which they are plug-fitted and soldered.
The location and arrangement of the valve seats and steam passages are shown in the sketch, the flat bar con¬ taining them being soldered to the top plate.
The steam chest A, over the valve mechanism, is constructed of 1-in.
square Grass tubing, one side being sawed out and the open ends fitted with pieces of iVin. sheet brass and soldered in. The steam inlet is a gas¬ oline-pipe connection, such as used on automobiles.
The valve-operating cams F are made of the metal ends of an old type¬ writer platen, one being finished to shape and then firmly fastened face to face to the other, and used as a pat¬ tern in filing the other to shape. At¬ tachment to the shaft N is by means of setscrews which pass through the sleeves. In shaping the cams as well as making the crankshaft, be sure to get the parts uniform so that they will run freely in their bearings and not bind. This will insure a free engine that will take but little steam to drive.
The main bearings M on the sup¬ ports O, and the crank-end bearings of the connecting rod K, are split and held in position by means of machine
2
screws with provision for taking them up when worn.
The exhausting of spent steam is accomplished by means of slots, I, sawed into the fronts of the cylinders at about Vs in. above the lowest posi¬ tion of the piston’s top at the end of the stroke, at which position of the piston the valve rod drops into the cut¬ out portion of the cam and allows the valve to seat/
All the work on this engine, save turning the pistons, which was done
in a machine shop for a small sum, and making the flywheel, this being taken from an old dismantled model, was accomplished with a hacksaw, bench drill, carborundum wheel, files, taps and dies. The base, Q, is made of a heavy piece of brass.
The action is smooth and the speed high. Steam is supplied by a sheet- brass boiler of about 3 pt. capacity, heated with a Bunsen burner. — Con¬ tributed by Harry F. Lowe, Wash¬ ington, D. C.
Magic Spirit Hand
The magic hand made of wax is given to the audience for examination, also a board which is suspended by four pieces of common picture-frame wire. The hand is placed upon the board and answers, by rapping, any question asked by members of the au¬ dience. The hand and the board may be examined at any time and yet the rapping can be continued, though sur¬ rounded by the audience.
The Magic Wand, London, gives the secret of this spirit hand as fol¬ lows: The hand is prepared by con¬ cealing in the wrist a few soft iron plates, the wrist being afterwards bound with black velvet as shown in Fig. 1. The board is hollow, the top being made of thin veneer (Fig. 2). A small magnet, A, is connected to a small flat pocket lamp battery, B. The board is suspended by four lengths of picture-frame wire one of which, E, is
Wax Hand on Board
a connecting plug at the top. The plug can be taken out or put in as de¬ sired.
The top of the board must be made to open or slide off so that when the battery is exhausted a new one can be installed. Everything must be firmly fixed to the board and the hollow space filled in with wax, which will make the board sound solid when tapped.
In presenting the trick, the per¬ former gives the hand and board with wires and switch for examination, keeping the plug concealed in his right hand. When receiving the board back, the plug is secretly pushed into the switch, which is held in the right hand. The hand is then placed on the board over the magnet. When the performer wishes the hand to move he pushes the plug in, which turns on the current and causes the magnet to at¬ tract the iron in the wrist, and will,
connected to the battery and another, D, to the magnet. The other wires, F and G, are only holding wires. All the wires are fastened to a small orna¬ mental switch, H, which is fitted with
therefore, make the hand rap. The switch can be made similar to an or¬ dinary push button so the rapping may be easily controlled without de¬ tection by the audience.
3
During the winter months everyone is thinking of skating, coasting or ski- running and jumping. Those too timid to run down a hill standing up¬ right on skis must take their pleasure in coasting or skating.
The ordinary ski can be made into a coasting ski-toboggan by joining two pairs together with bars without in¬ jury to their use for running and jump¬ ing. The ordinary factory-made skis cost from $2.50 per pair up, but any boy can make an excellent pair for 50 cents. <
In making a pair of skis, select two strips of Norway pine free from knots, 1 in. thick, 4 in. wide and 7 or 8 ft. long. Try to procure as fine and straight a grain as possible. The pieces are dressed thin at both ends leaving about 1 ft. in the center the full thickness of 1 in., and gradually thinning to a scant % in. at the ends. One end of each piece is tapered to a point beginning 12 in. from the end. A groove is cut on the under side, about % in. wide and % in. deep, and running almost the full length of the ski. This will make it track straight and tends to prevent side slipping. The shape of each piece for a ski, as it appears before bending, is shown in Fig. 1.
The pointed end of each piece is placed in boiling water for at least 1 hour, after which the pieces are ready for bending. The bend is made on an ordinary stepladder. The pointed ends are stuck under the back of one step and the other end securely tied to the
ladder, as shown in Fig. 2. The}^ should remain tied to the ladder 48 hours in a moderate temperature, after which they will hold their shape permanently.
The two straps, Fig. 3, are nailed on a little forward of the center of gravity so that when the foot is lifted, the front
Fig. 1 Fig. 2
■ — Q-. ^
Fig. 3— Forming the Skis
of the ski will be raised. Tack on a piece of sheepskin or deer hide where the foot rests, Fig. 4.
The best finish for skis is boiled lin¬ seed oil. After two or three applica-
4
Fig. 4 — The Toe Straps
tions the under side will take a polish like glass from the contact with the snow.
The ski-toboggan is made by placing two pairs of skis together side by side
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Fig. 5 — Ski-Toboggan |
and fastening them with two bars across the top. The bars are held with V-shaped metal clips as shown in Fig. 5. — Contributed by Frank Scobie, Sleepy Eye, Minn.
Homemade Life Preserver
Procure an inner tube of a bicycle tire, the closed-end kind, and fold it in four alternate sections, as shown in Fig. 1. Cut or tear a piece of cloth into strips about % in. wide, and knot them together. Fasten this long strip of cloth to the folded tube and weave it alternately in and out, having each
Fig. I
run of the cloth about 4 in. apart, un¬ til it is bound as shown in Fig. 1.
Make a case of canvas that will snugly fit the folded tube when in¬
flated. The straps that hold the pre¬ server to the body may be made of old .suspender straps. They are sewed to the case at one end and fastened at the other with clasps such as used on over¬ all straps. The tube can be easily in¬ flated by blowing into the valve, at the same time holding the valve stem down with the teeth. The finished preserver is shown in Fig. 2.
How to Make Boomerangs
When the ice is too thin for skating and the snow is not right for skis, about the only thing to do is to stay in the house. A boomerang club will help to fill in between and also fur¬ nishes good exercise for the muscles of the arm. A boomerang can be made
of a piece of well seasoned hickory plank. The plank is well steamed in a wash "boiler or other large kettle and then bent to a nice curve, as shown in Fig. 1. It is held in this curve until dry, with two pieces nailed on the sides as shown.
After the piece is thoroughly dried out, remove the side pieces and cut it into sections with a saw, as shown in Fig. 2. The pieces are then dressed round. A piece of plank 12 in. wide and 2 ft. long will make six boom¬ erangs.
To throw a boomerang, grasp it and hold the same as a club, with the hol¬ low side away from you. Practice first at some object about 25 ft. distant, and in a short time the thrower will be able to hit the mark over 100 ft. away. Any worker in wood can turn out a great number of boomerangs cheaply. —Contributed by J. E. Noble, Toronto* Ontario.
V
5
How to Make an Eskimo Snow House
By GEORGE E. WALSH
Playing in the snow can be raised to a fine art if boys and girls will build their creations with some attempt at architectural skill and not content themselves with mere rough work. Working in snow and ice opens a wide field for an expression of taste and invention, but the construction of houses and forts out of this plastic material provides the greatest amount of pleasure to the normally healthy boy or girl.
The snow house of the Eskimo is probably the unhealthiest of buildings made by any sav¬ age to live in, but it makes an excel¬ lent playhouse in winter, and repre¬ sents at the same time a most ingen¬ ious employment of the arch sys¬ tem in building.
The Eskimos build their snow houses without the aid of any scaf¬ folding or interior falsework, and while there is a keystone at the top of the dome, it is not essential to the support of the walls. These are self-support¬ ing from the time the first snow blocks are put down until the last course is laid.
The snow house is of the beehive shape and the ground plan is that of a circle. The circle is first laid out on the ground and a space cleared for it. Then a row of snow blocks is laid on the ground and another course of similar blocks placed on top. The snow blocks are not exactly square in shape, but about 12 in. long, 6 in. high and 4 or 5 in. thick. Larger or smaller blocks can be used, according to size of the house and thickness of the walls.
First, the snow blocks must be packed and pressed firmly into position out of moist snow that will pack. A very light, dry snow will not pack easily, and it may be necessary to use a little water. If the snow is of the right consistency, there will be no trouble in packing and working with it. As most of the blocks are to be of the same size throughout, it will pay to make a mold for them by forming a box of old boards nailed together, minus the top, and with a movable bottom, or rather no bottom at all.
Place the four¬ sided box on a flat board and ram snow in it, forcing it down closely. Then by lifting the box up and tapping the box from above, the block will drop out. In this way blocks of uniform size are formed, which makes the building simpler and easier.
While one boy makes the blocks an¬ other can shave them off at the edges and two others can build the house, one inside of the circle and the other outside. The Eskimos build their snow houses in this way, and the man inside stays there until he is completely walled in. Then the door and a win¬ dow are cut through the wall.
Each layer of snow blocks must have a slight slant at the top toward the center so that the walls will con-
Three-Room Snow House
6
stantly curve inward. This slant at the top is obtained better by slicing off the lower surfaces of each block before putting it in its course. The top will then have a uniform inward slant.
The first course of the snow house should be thicker than the others, and the thickness of the walls gradually decreases toward the top. A wall, however, made of 6-in. blocks through¬ out will hold up a snow house perfectly, if its top is no more than 6 or 7 ft. above the ground. If a higher house is needed the walls should be thicker at the base and well up toward the middle.
The builder has no mortar for bind¬ ing the blocks together, and therefore he must make his joints smooth and even and force in loose snow to fill up the crevices. A little experience will enable one to do this work well, and the construction of the house will proceed rapidly. The Eskimos build
additions to their houses by adding various dome-shaped structures to one side, and the young architect can imi¬ tate them. Such dome-shaped struc¬ tures are shown in one of the illus¬ trations.
A fact not well understood and ap¬ preciated is that the Eskimo beehive snow house represents true arch build¬ ing. It requires no scaffolding in build¬ ing and it exerts no outward thrust In the ordinary keystone arch used by builders, a temporary structure must be erected to hold the walls up until the keystone is fitted in position, and the base must be buttressed against an outward thrust. The Eski¬ mo does not have to consider these points. There is no outward thrust, and the top keystone is not necessary to hold the structure up. It is doubt¬ ful whether such an arch could be built of brick or stone without scaffolding, but with the snow blocks it is a simple matter.
Secret Door Lock
The sketch shows the construction of a lock I have on a door which is quite a mystery to those who do not know how it operates. It also keeps them out. The parts of the lock on the in¬ side of the door are shown in Fig. 1. These parts can be covered so that no one can see them.
The Lock Parts
The ordinary latch and catch A are attached to the door in the usual man¬ ner. The latch is lifted with a stick of wood B, which is about 1 ft. long and 1 in. wide, and pivoted about two-
thirds of the way from the top as shown. The latch A is connected to the stick B with a strong cord run through a staple to secure a right-an¬ gle pull between the pieces. A nail, C, keeps the stick B from falling over to the left. The piece of wood, D, is 6 or 8 in. long and attached to a bolt that runs through the door, the opposite end being fastened to the combination dial. Two kinds of dials are shown in Fig. 2. The piece D is fastened on the bolt an inch or two from the surface of the door to permit placing a spiral spring of medium strength in between as shown in Fig. 3. The opposite end of the bolt may be screwed into the dial, which can be made of wood, or an old safe dial will do. A nail is driven through the outer end of the piece D and the end cut off so that it will pass over the piece B when .the dial is turned. When the dial is pulled out slightly and then turned toward the right, the nail will catch on the
piece B and open the latch. — Contrib¬ uted by Geo. Goodbrod, Union, Ore.
A Convenient Hot-Dish Holder
When taking hot dishes from the stove, it is very convenient to have holders handy for use. For this pur¬ pose I screwed two screweyes into the ceiling, one in front of the stove di¬ rectly above the place where the holder should hang, and the other back of the stove and out of the way. I next ran a strong cord through the two eyes. To one end of the cord I attached a weight made of a clean lump of coal. The cord being just long enough to let the weight hang a few inches above the floor and pass through both screw- eyes. I fastened a small ring to the other end to keep the cord from slip¬ ping back by the pull of the weight. I then fastened two pieces of string to the ring at the end of the cord and at¬ tached an iron holder to the end of each string. The strings should be just long enough to keep the holders just over the stove where they are al¬
ways ready for use, as the weight always draws them back to place. — Contributed by R. S. Merrill, Syracuse, New York.
Magic-Box Escape
The things required to make this trick are a heavy packing box with cover, one pair of special hinges, one or two hasps for as many padlocks and a small buttonhook, says the Sphinx.
The hinges must be the kind for at¬ taching inside of the box. If ordinary butts are used, the cover of the box
must be cut as much short as the thickness of the end board. The hinges should have pins that will slip easily through the parts.
Before entering the box the per¬ former conceals the buttonhook on his person, and as soon as the cover is closed and locked, and the box placed in a cabinet or behind a screen, he pushes the pin or bolt of the hinge out far enough to engage the knob end with the buttonhook which is used to pull the pin from the hinge. Both hinges are treated in this manner and the cover pushed up, allowing the per¬ former to get out and unlock the pad¬ locks with a duplicate key. The bolts are replaced in the hinges, the box relocked and the performer steps out in view.
A Flour Sifter
When sifting flour in an ordinary sieve I hasten the process and avoid the disagreeable necessity of keeping my hands in the flour by taking the top from a small tin lard can and placing it on top of the flour with its sharp edges down. When the sieve is shaken, the can top will round up the flour and press it through quickly. — Contributed by L. Alberta Norrell, Augusta, Ga.
GAn automobile horn with the bulb and reed detached makes a good funnel. It must be thoroughly cleaned and dried after using as a funnel.
8
How to Make Comer Pieces for a Blotter Pad
To protect the corners of blotting pads such as will be found on almost every writing desk, proceed as follows :
First, make a design of a size pro¬ portionate to the size of the pad and make a right-angled triangle, as shown in Fig. 1, on drawing paper. Leave a small margin all around the edge and then place some decorative form there¬ in. Make allowance for flaps on two sides, as shown, which may later be turned back and folded under when the metal is worked. It should be noted that the corners of the design are to be clipped slightly. Also note the slight overrun at the top with the re¬ sulting V-shaped indentation.
To make a design similar to the one shown, draw one-half of it, then fold along the center line and rub the back of the paper with a knife handle or some other hard, smooth surface, and the other half of the design will be traced on the second side. With the metal shears, cut out four pieces of copper or brass of No. 22 gauge and with carbon paper trace the shape and decorative design on the metal. Then cut out the outline and file the edges smooth.
Cover the metal over with two coats of black asphaltum varnish, allowing each coat time to dry. Cover the back and all the face except the white back¬ ground. Immerse in a solution of 3 parts water, 1 part nitric acid and 1 part sulphuric acid. When the metal has been etched to the desired depth, about 1-32 of an inch, remove it and clean off the asphaltum with turpen¬ tine. Use a stick with a rag tied on the end for this purpose so as to keep the solution off the hands and clothes. The four pieces should be worked at the same time, one for each corner.
It remains to bend the flaps. Place the piece in a vise, as shown in Fig. 2, and bend the flap sharply to a right angle. Next place a piece of metal of a thickness equal to that of the blotter pad at the bend and with the mallet bring the flap down parallel to the face
of the corner piece, Fig. 3. If the measuring has been done properly, the flaps ought to meet snugly at the cor¬ ner. If they do not, it may be neces-
Manner of Forming the Plates
sary to bend them back and either re¬