Step A consists in properly planing up a straight-grained block of white pine 1½ inches thick, 2 inches wide, and 9 inches long, with its sides and ends straight and true, for
The Propeller Blank. Draw a line around the four faces of this block at the exact center of the length. Then on faces C and D, lay off a distance of ½ inch on the center-line, measuring from the edge of face B, for the thickness of the propeller-hub, and draw diagonal lines from the upper and lower left-hand corners of faces C and D to the end of the hub center-line (Step B). Then cut away the portions outside of these lines, as shown in Step C. Lay out the hub upon faces A and B of the block, with a ½-inch diameter, and bore a small hole through the center to receive the propeller-shaft (Step C). Draw diagonals from the corners to the center-line of the hub (Step D); then cut away the wood outside of these lines (Step E).
The next step (F) consists in laying out the form of the propeller blade upon all four sides and ends of the block, and Step G is the final one of cutting out the propeller, scooping out its blades concave on one side, and carving them convex on the opposite side. A very sharp knife must be used for cutting; and the work must be done slowly and carefully, because the least slip is likely to ruin the propeller. The entering-edge of each blade is the almost straight edge, and should be cut very thin. The ends of the blades should also be cut thin, while the hub should be cut away as much as can safely be done without weakening the propeller.
When you have completed cutting the propellers, place them at their centers across the edge of a knife-blade, and if they do not balance perfectly, locate the trouble and correct it. Finish the work with fine emery-paper, and then shellac it. Some boys glue silk over the ends of their propeller blades, for a distance of ½ inch or so, to reinforce them and make them less likely to split.
The Propeller-shafts are made of heavy piano-wire, bent into a hook at one end (Fig. 38) to receive the rubber strands of the motor, and cut of the right length to extend through the hole in the bearing, through a glass bead, through the propeller, and then to bend over the side of the hub (Figs. 37 and 38). By bending over the end of the shaft against the hub, it is held securely in place.
The Motors consist of twelve strands of 1/8-inch flat rubber, each, and as these are 1 yard in length, exactly 24 yards of rubber are required. The rubber is not connected direct to the hooks on the bow and propeller-shafts, as the wire would quickly cut through the strands. Instead, small rings are bent out of wire, with pieces of small rubber-tubing slipped over the wire, and the ends of the rubber strands are looped through these rings and bound in place with thread (Fig. 39). The wire rings are then slipped on and off the hooks quickly. As light and heat cause rubber to deteriorate, you must remove the motors from the machine after use, pack away in a covered box, and keep in a cool place, in order to get the longest life possible out of the rubber.
It has been found that rubber motors can be wound much farther by lubricating them with glycerine. It is only necessary to put a few drops of the glycerine upon a clean cloth, and rub it over the outside strands; then wind the motors, and it will work over the surface of the inner strands until all parts are covered.
Fig. 45.—A Home-made Motor Winder.
Fig. 46.—The Kind of Egg-beater to Use.
Fig. 47.—How the Motors are Connected to Winder for Winding.
Of course the rubber motors must be twisted an equal number of turns, in order to make the propellers work the same, and this is usually done with an ingenious winder made from an egg-beater, which winds both motors simultaneously.
The Home-made Motor-winder shown in Fig. 45 is made from a Dover egg-beater (Fig. 46). To convert the egg-beater into a winder, it is necessary to cut off the loop ends and the center pivot wires on which the loops turn. Then bend the cut-off ends of the loops into hooks, and punch them to fit over the pivot wire ends, as before (Fig. 45). The ends of the pivot wires must be riveted to keep the hooks in position.
Figure 47 shows
How the Egg-beater Winds the Motors. While an assistant supports the model by the propeller end, you remove the motor rings from the hooks on the bow of the fuselage, and slip them on to the hooks of the egg-beater. Then you turn the crank of the winder, counting the turns as you do so, and when you have wound the motors as far as you wish, slip off the motor rings, and slip them back on to the bow hooks of the model aeroplane. Motors of models like that shown in this chapter are wound one-thousand turns or more for each flight.
Wind the Motors Slowly, especially after the first row of knots begin, as it puts the rubber to the least amount of strain by doing this. Quick winding not only strains the rubber but makes the knots form in bunches, and uneven winding, of course, produces an uneven unwinding.
The propellers must be held after the motors have been wound, to keep them in check. Figure 34 shows
The Position to Take for Launching a Model from the hand. The machine should not be thrown forward, as the movement would cause too great a disturbance of the air, resulting in the machine losing its stability, and probably upsetting. The best method is to give the model a slight push that will start it off at a speed a trifle under that produced by its propellers.
The toy motor-boat shown in Figs. 48 and 49 is propelled by a tin propeller run by a rubber-band motor. A handful of rubber-bands will cost only a few cents, and the rest of the working material can be picked up at home.
Prepare the Bottom of the Hull out of a piece of wood 1 inch thick, making it of the shape and dimensions shown in Fig. 51. Be careful to curve the side edges the same. Use a saw for cutting out the piece, then smooth up the edges with a plane and sandpaper. The stern should be sawed off on a bevel as shown in Fig. 52.
The Sides of the hull (B, Figs. 52 and 53) are thin strips 2½ inches wide. Nail one to one edge of the bottom block, then saw off the bow end on a line with the bow of the bottom block, and the stern end on the same slant as the bevel cut on the stern of the bottom block. With one piece in position, nail on the second side and trim off its ends. If you have any difficulty in making a neat joint between the bow ends of sides B, take a piece of tin from a can, bend it around the bow, and tack it in place as shown in Fig. 48. The stern piece (C, Figs. 53 and 54) should be cut next, to fit the slanted ends of the sides.
Figs. 52 and 53.—How the Hull, Sides, Stern and Deck Pieces are Assembled.
The Deck (D) extends from the bow almost to the center of the boat. Its top surface should taper in its length and curve from side to side. The piece may be whittled or planed to this shape. Fasten it with brads to the top edges of the sides of the boat.
To Complete the Boat, go over the work carefully, trim off all projecting edges, drive nail heads beneath the surfaces, putty nail holes and cracks, and give the wood two coats of paint of whatever color you want to have the motor-boat.
The Propeller (E, Fig. 54) is cut from the side of a tin can. Cut a piece 3 inches long and ¾ inch wide, round its ends, and with the point of a nail pierce a hole through it each side of the center of the length of the piece (Fig. 55). To finish the propeller, it is only necessary to take hold of the two ends and twist the piece into the shape shown in Fig. 56.
The Propeller-shaft requires a short piece of wire with one end bent into a hook (F, Fig. 56). Stick the straight end of this shaft through one hole in the propeller, and the hooked end through the other hole, then twist the hooked end over on to the main part of the shaft, as shown in Fig. 57. Make a tight twist so the propeller will be held perfectly rigid on the shaft.
The Bearing Plate G (Figs. 54 and 58) supports the propeller. Cut it out of a piece of tin 1½ inches wide by 3 inches long, bend it in half crosswise to give it stiffness, and then bend it lengthwise to the angle shown so it will fit over the slanted stern of the boat. Punch two holes through the upper end for nailing the plate to the stern, and a hole at the lower end for the propeller-shaft to run through.
For a Thrust Bearing, slip a couple of beads over the propeller-shaft, between the propeller and bearing plate G. Probably you can find glass beads in your mother's button bag.
Fig. 54.—Longitudinal Section of Assembled Motor-boat.
Figs. 55-59.—Details of Propeller.
Fig. 60.—Rubber-band Motor.
After slipping the beads on to the shaft, and sticking the shaft through the hole in bearing plate G, bend the end of the shaft into a hook; then screw a small screw-hook into the bottom of the hull, at the bow end (I, Fig. 54), and you will be ready for
The Rubber-band Motor. Rubber-bands about 1½ inches in length are best for the purpose. Loop these together end to end (Fig. 60) to form a strand that will reach from hook I to the hook on the propeller-shaft; then form three more strands of this same length, and slip the end loops of all four strands over the hooks.
To Wind the Motor, give the propeller about one hundred turns with your finger; then, keep hold of the propeller until you launch the boat.
There are many ways of elaborating upon the design and construction of this toy motor-boat, but, having given the necessary instructions for building a simple model, I am going to leave further development for you to work out. Here is an opportunity for you to use your ingenuity. Devise an adjustable rudder, add a keel, finish off the cockpit with a coaming, install a headlight made from a pocket flashlight—in fact, see just how complete a motor-boat model you can build.
You can own a water-motor like the one shown in Fig. 61, because its construction requires nothing but easily obtained materials.
The Case of this water-motor is made of an empty varnish can—preferably one of gallon capacity. Nothing better could be desired. The tin can makes a lightweight compact case; the spout in the top is in just the right place and of the right size to receive the water power from a faucet; and as the water connections can be made tight there is no possibility of water splashing on to the floor—a big argument in your favor when seeking permission to use the motor in the bath-tub, wash-basin, or kitchen sink.
You can get an empty varnish can from any painter, or at a paint store. The first step in converting the can into the motor case consists in removing the bottom. You will find this soldered in place, in all probability, and it can be removed quickly by holding the can over the flame of a gas burner until the solder melts, when a few taps upon the edges will cause the piece of tin to drop off.
The Water-motor Wheel is shown in the cross-sections of the water-motor (Figs. 63 and 64), and Figs. 65 to 67 show its details. The diameter of the wheel should be about ½ inch less than the inside width of the can. In the model from which the drawings were made, this measurement is 5½ inches. Cut the two side pieces of the wheel out of a piece of cigar-box wood, and bore a ¼-inch hole through the center of each for the wheel axle. Fasten a spool to the center of one side piece for a pulley-wheel (Fig. 66).
Prepare Eight Paddles 1¾ inches wide and 2½ inches long, out of cigar-box wood. Locate the positions for the ends of the paddles, upon the side pieces, by drawing a horizontal line, a vertical line, and two diagonal lines at angles of 45 degrees, through their centers. This will simplify the matter of spacing the paddles equidistant from one another (Fig. 67). Use brads for fastening the side pieces to the paddle ends. Those removed from the cigar boxes will do.
The Wheel Shaft should be a trifle shorter than the inside width of the can, and enough smaller than the ¼-inch hole in the wheel side pieces so the wheel will turn freely. Locate the centers for the axle upon the two sides of the can, in the proper position so there will be the same margin above and at the ends of the wheel. Drive a nail through each side of the can into the axle end.
Fig. 65.—The Completed Water-motor Wheel.
Figs. 66 and 67.—Details of Water-motor Wheel.
An Outlet for the water after it has passed over the wheel paddles must be provided, and the best way is to fasten a strip to two opposite sides of the can so as to raise the bottom about an inch, as shown in Figs. 62, 63, and 64.
For a Pulley-belt use a piece of heavy cord. Cut a slot through the front of the can for the belt to run through, and make this slot large enough so the cord will not rub against the sides (Fig. 63).
Pulley-wheels for attaining different speeds can be made of spools of various sizes. A bicycle wheel with the tire removed, mounted in a frame, is excellent for a large wheel.
Figs. 68-69.—How to Make a Water-tight Connection between Faucet and Water-motor.
Connecting up the Water-motor. If you operate the water-motor in the kitchen sink, you can either build a platform as shown in Fig. 61, to bring the spout of the varnish-can case up to the level of the faucet, or you can set the water-motor in the sink and lead a piece of rubber tubing from the spout to the faucet, as shown in Fig. 68. If you use the latter arrangement, slip the lower end of the rubber tubing over a short piece of glass, brass, or tin tubing, and stick the short tubing through a hole in a cork large enough to fit the spout of the varnish-can case (Fig. 69). If you raise the water-motor high enough so the faucet will set down into the spout, you can cut a large enough hole for the faucet, through a cork, and then fit the cork in the spout as shown in Fig. 64.
Another Water-motor. The little water-motor in Fig. 70 will furnish sufficient power to operate simple mechanical toys.
The Water-motor Wheel. Procure two baking-powder can covers for the ends of the water-motor wheel (A, Fig. 72), a cigar-box out of which to make the wheel paddles, and a stick ¼ inch square and 5 inches long for the wheel axle (B, Fig. 72).
Fig. 70.—A Small Water-motor that can be Operated in a Wash-Basin.
Figs. 72 and 73.—Details of Water-motor Wheel.
Cut eight paddles from the cigar-box wood 1 inch wide and 5 inches long. Take a pair of these strips and fasten them to one can cover, in line with each other, and close against the sides of the cover (C, Fig. 73). Fasten with tacks or brads driven through the cover into the ends of the strips. Take another pair of strips and fasten them to the same cover, in a similar manner, at right angles to pair C (D, Fig. 72). Then tack the pairs of strips E and F to the cover halfway between pairs C and D. With the paddles in position, locate the exact center of the end of the can cover, and drive a nail through at this point into the end of axle B. Slip the free ends of the paddles into the other can cover, and carefully drive tacks or brads through the cover into them. Drive a nail through the center of the cover into the end of axle B.
The Wheel Supports. Figure 74 shows the supports for the wheel. Cut the end pieces G 4 inches wide and 6 inches high, and the cross strips H 1¾ inches wide and 5½ inches long. Nail pieces G to H, as shown, allowing the lower ends of G to extend ½ inch below strips H, and leaving a space of ½ inch between strips H. The axle holes in pieces G (Fig. 74) should be located in the center of the width of these pieces, and halfway between their tops and strips H. Bore the holes with a gimlet, or make them by driving a large nail through the pieces, and then withdrawing it.
To Mount the Wheel upon the supports, withdraw the nails driven into the ends of axle B, slip the wheel between uprights G, and drive the nails through the holes in G back into the holes in the axle ends (Fig. 71).
The Pulley Wheel. One can cover should be converted into a pulley by winding several turns of string around it, near each edge, leaving a groove between the string. Coat the string with glue to make it stick fast to the cover.
The Water-motor Case. Figure 70 shows how the water-motor case is constructed by fastening boards N, I, J, K, L, and M to the wheel supports G. There must be a slot through I and another through J, for the string belt to pass through, and a hole through K for the intake of water from a faucet. These can be cut out of the edges of the boards, as shown, before they are nailed in place. Leave an opening between boards N and M, and the bottom of ends G, for an outlet for waste water.
It is often thought that a toy railway is beyond a boy's ingenuity to construct, whereas, in reality, it is one of the simplest toys he can make. This applies to the tracks, stations, and cars of every description, all of which can be made with a few strips of wood, some spools, nails, cardboard, and a bottle of glue, for materials. If you have passed the age of caring for such toys as this, you will, no doubt, enjoy the making of one for your younger brother, or for one of your boy relatives.
Figure 76 shows a railway set up and in running order. As shown in the illustration,
The Trolley-line, or overhead cable, runs around the wheels of two supports, one at either end of the track. Prepare four pieces of wood the shape and size of that shown in Fig. 75 for the uprights of these supports, and make two wheels three inches in diameter. The wheels may be marked out with a home-made compass—a pencil tied to the end of a piece of string, if you haven't a compass. When the wheels have been cut out, place them in your bench-vise, one at a time, and with a file make a groove around the edge as shown at C, Fig. 77. Bore a three-eighths-inch hole through each upright at F, Fig. 75, and another through the center of each wheel. Now fasten two of the uprights six inches apart upon a block of wood, as shown at A and B, Fig. 77. Whittle a shaft to fit loosely in the holes of the uprights, and, after slipping it into them, fasten one of the wheels upon one end and a small spool upon the other (see C and D in Fig. 77). A weight of some sort should be fastened to the base, as shown at E. The uprights for the other support should be similarly mounted upon another block of wood. Fasten the remaining wheel to an axle run through the holes in the uprights, and, as it is unnecessary to have a spool upon the other end of the axle, cut it off short and drive a nail through it to prevent it from slipping through the holes. Having thus prepared the supports, place them as far apart as you wish to extend the railway, and run a cord around the two wheels and tie it. Then set the supports a little farther apart, if necessary, to tighten the cord. Run another cord from spool D to
A Water-motor, steam engine, or whatever power you can get with which to operate the railway. A bicycle inverted with the tire removed from its rear wheel has been used satisfactorily, as has also a sewing-machine with the belt slipped off and the cord from the spool put in its place.
A good substitute for the tin tracks ordinarily sold in shops for toy railways will be found in those shown in Fig. 78. These
Tracks consist of quarter-inch strips mounted upon pieces of cardboard. Make a small gimlet-hole in one end of each stick, and drive a short finishing nail in the opposite end (see Fig. 78). Cut the cardboard strips the length of the sticks, and tack them to the sticks as shown in the illustration. If inch and one-half spools are used for the car wheels, the inside gauge of the tracks should be an inch and three-quarters. By lapping the cardboard strips over the ends of the sticks, and the sticks over the ends of the cardboard strips, and placing the nail dowels in the ends of the sticks as in the drawing, a strong track is formed when the pieces are fitted together. This may be extended to any desired length by adding more sections to it.
The Cars for this railway will have their trucks constructed alike, and it is a simple matter to transform a car from one style into another. Figure 79 shows a top view of a truck. For the bed of this cut a three-eighths-inch board twelve inches long by two and one-quarter inches wide, and, after rounding the ends as shown in the drawing, cut a mortise at A and B two and three-eighths inches from either end.
Procure two one and one-half inch spools for wheels, and drive a wooden peg through the hole in each, cutting off the ends so they project a little beyond the hole, as shown in Fig. 80. Then bore four holes in the edges of the truck-bed with a gimlet at C, D, E, and F (see Fig. 79), and, after setting the spools in mortises A and B, pivot them in place with small finishing nails driven into the wooden pegs. These nails should fit loosely in the gimlet holes. In order to drive them into the exact centers of the spools, it is best to locate these points upon the ends of the pegs before placing the spools in the frame. A quarter-inch hole should be bored in the top of the truck-bed at G and H (Fig. 79) in which to fasten the two uprights I and J (see Fig. 81). Make the uprights four inches long and whittle a peg upon the lower ends to fit holes G and H (see Fig. 82). Bore a hole with a gimlet in the top of each and run a piece of heavy wire from one to the other, bending it as shown in Fig. 81. Fasten K between I and J, as shown. Place a small brass ring upon the wire before you fasten it in place. A small hook should be screwed into one end of the truck and a screw-eye into the other end, for couplings, should you wish to hitch two or more cars together.
A Gondola Car, such as shown in Fig. 83, should have its truck made similar to Fig. 79, with the exception that it should be two inches shorter, in order that cigar-box strips can be used for the side pieces. Cut the strips an inch and one-half high and fasten them to the bed of the car with brads. This car may be used as a trailer.
The car shown in Fig. 81 is a rather crude affair, but with a little more work may be transformed into a better looking car—
A Street Car such as is shown in Figs. 84 and 85 being an example of what can be made. The sides, ends, and roof of this car are made of cardboard, the patterns for the cutting of which are shown on page 55. Figure 86 shows a cross-section taken through the center of the car. The two side pieces A should be prepared first, as shown in Fig. 87. With a ruler and lead-pencil draw in the windows about as shown in the drawing, using double lines to indicate the sash. Then, with a sharp knife, cut out the center of each just inside of the inner line. These windows may be left open or may be covered on the inside with tissue-paper. If tissue-paper is used, oil it to make it more transparent. When the two sides have been prepared, bend each along the dotted lines (see Fig. 87) and tack one to each side of your car truck as shown in Fig. 86. When properly bent, the distance between the upper part of the sides should be two and three-quarters inches. Cut the two inner ends of the car the shape of Fig. 88, using a compass with a radius of two and one-half inches with which to describe the curve at the top. Draw in the panels and sash lines as you did those upon the side pieces, being careful to get them on the same level, and cut out the door and window openings. Fasten these end pieces between the sides with glue, and also tack them to the uprights of the car (I and J, Fig. 81), which will come just inside of them. The roof is made in two sections (B and C, Fig. 86). For B cut a piece of cardboard twelve and one-quarter by three and three-quarter inches (Fig. 89), draw the curved end with a compass, using the radius shown on the drawing, and slit the corners as indicated by the dotted lines. When this piece has thus been prepared, remove the wire from the top of the truck (see Fig. 81). Bend the cardboard over the sides and ends of the car, and lap corners D and E over F and G, and H and I over J and K, tacking them with thread to hold them in place. To fasten this part of the roof to the top of the car, cut a number of small strips of linen, and glue them to the under side of the roof and to the inside face of the sides and ends of the car (see Fig. 86). The upper portion of the roof C should be made out of a piece of cardboard bent into the shape of Fig. 90, and cut at the ends so the upper portion of C projects a little beyond its sides. Draw the ventilation lights upon the sides of C as shown on the drawings, and then fasten the piece upon the top of B with strips of linen in the same manner as you fastened B in place. C should now have the same curve to its top as B. Cut and glue a piece of cardboard in each end of C to complete the roof. The shape of this piece is shown in Fig. 91. The outer ends of the car should be made as shown in Fig. 92, and tacked around the ends of the wooden truck platform, and also fastened to the under side of the roof with strips of linen.