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| Title Chapter I |
No mechanical toy is more interesting to make, nor more interesting to watch in operation, than a miniature windmill. It is a very simple toy to construct, and the material for making one can usually be found at hand, which are two reasons why nearly every boy and girl at one time or another builds one.
The Paper Pinwheel shown in Fig. 1 is one of the best whirlers ever devised. A slight forward thrust of the stick handle upon which it is mounted starts it in motion, and when you run with the stick extended in front of you it whirls at a merry speed.
Fig. 1.—The Paper Pinwheel is the Simplest Pinwheel to Make.
A piece of paper 8 or 10 inches square is needed for the pinwheel. Fold this piece of paper diagonally from corner to corner, both ways. Then open the paper, and with a pair of scissors cut along the diagonal creases, from the corners to within ½ inch of the center (Fig. 2). Next, fold corners A, B, C, and D over to the center, as shown in Fig. 3, run a pin through the corners and through the center of the sheet of paper, drive the point of this pin into the end of the stick handle, and the pinwheel will be completed.
The Pinion-wheel Windmill in Fig. 4 may be made of cardboard or tin. A circular piece 10 or 12 inches in diameter is required. After marking out the outer edge with a compass, describe an inner circle about 1 inch inside of it; then draw two lines through the center at right angles to each other, and another pair at an angle of 45 degrees to these. These lines are shown by the heavy radial lines in Fig. 5. One-half inch from each of these lines draw a parallel line, as indicated by dotted lines in Fig. 5. The next thing to do is to cut out the disk, and cut along the heavy lines just as far as the lines are shown in the diagram (Fig. 5), and then to bend up the blades thus separated, to an angle of about 45 degrees, bending on the second set of radial lines (dotted lines in Fig. 5).
You had better make a cardboard pinion-wheel first, then a tin one afterwards, as cardboard is so much easier to cut. A pair of heavy shears will be necessary for cutting a tin wheel, and a cold chisel for separating the edges of the blades.
To Mount the Pinion-wheel drive a long nail through the center, through the hole in a spool, and into the end of a stick. Then nail the stick to a post or a fence top.
The Four-blade Windmill shown in Fig. 6 has a hub 4 inches in diameter and 1 inch thick (Fig. 7). This should be cut out of hard wood. Draw two lines across one face, through the center, and at right angles to each other. Then carry these lines across the edge of the block, not at right angles to the sides, but at an angle of 45 degrees. Saw along these lines to a depth of 1¼ inches. The ends of the windmill blades are to fit in these slots.
Cut the blades of equal size, 9 inches long, 5 inches wide on the wide edge, and 1½ inches wide on the narrow edge, and fasten them in the slots with nails.
Fig. 6.—A Four-blade Windmill.
Fig. 7.—Hub
Fig. 8.—How to Slot End of Shaft for Tail.
With the blades in position, pivot the hub to the end of the windmill shaft, a stick 20 inches long (Fig. 6). The end opposite to that to which the hub is pivoted is whittled round, and slotted with a saw to receive a tail (Fig. 8). The tail may be of the same size as the blades, though it is shown shorter in the illustration.
Mount the Windmill upon a post, pivoting its shaft at the balancing center with a nail or screw. Bore a hole large enough so the shaft will turn freely upon the pivot, and the windmill will thus keep headed into the wind.
The Eight-blade Windmill in Fig. 9 has a spool hub (Fig. 10), and blades made of cigar-box wood, shingles, tin, or cardboard (Fig. 11). You will see by Figs. 10 and 11 that the blades are nailed to the side of short spoke sticks, and the sticks are driven into holes bored in the spool hub. The hub turns on the rounded end of the shaft stick (Fig. 12), and the square end of this shaft is slotted to receive the fan-shaped tail (Figs. 12 and 13).
For the Hub use a large ribbon-spool. You can get one at any drygoods store. Locate eight holes around the center of the spool at equal distances from one another, and bore these with a gimlet or bit, or cut them with the small blade of your jack-knife.
Cut the Eight Blades 6 inches long, 5 inches wide on their wide edge, and 1½ inches wide on their narrow edge. Prepare the hub sticks about ½ inch by ¾ inch by 4½ inches in size, and whittle one end pointed to fit in the hub (Fig. 11). Fasten the blades to the spokes with nails long enough to drive through the spokes and clinch on the under side. Glue the spokes in the hub holes, turning them so the blades will stand at about the angle shown.
The Shaft should be made of a hard wood stick about ¾ inch by 1½ inches by 30 inches in size. Cut the round end small enough so the hub will turn freely on it, and punch a small hole through it so a brad may be driven through to hold the hub in place. Cut the slot in the square end with a saw.
Cut the Tail of the shape shown in Fig. 13.
Pivot the Windmill upon the top of a post support, in the same manner as directed for the other windmills.
Figure 14 shows how the toy windmill may be rigged up
Fig. 14.—How the Windmill may be Rigged up to Operate a Toy Jumping-Jack.
To Operate a Toy Jumping-Jack, by supporting the jumping-Jack on a bracket, and connecting its string to the hub of the windmill. You can make your jumping-Jack like the one in Fig. 110, the details of which are shown in Fig. 113.
Cut the upright of the bracket (A, Figs. 14 and 15) 14 inches long, and the crosspiece (B) 7 inches long. Nail A to B, and nail the jumping-Jack at its center to the end of B (Fig. 15). Fasten the triangular block (C) to the lower end of A, and then nail both A and C to the edge of the shaft at a point that will bring the string of the jumping-Jack a trifle beyond the windmill blades.
Fasten a small stick with a brad driven in one end, in notches cut in the hub's flanges (Fig. 16), and connect the brad and Jack's string with a piece of wire or strong string. Then as the windmill revolves it will operate the toy in the manner indicated in Figs. 14 and 15.
The Malay tailless kite is probably the most practical kind ever invented. It will fly in a wind that the tail variety could not withstand, and it will fly in a breeze too light to carry up most other forms of kites. It is also a strong pulling kite, and can be used for sending aloft lanterns and flags. For the purpose of lifting, the pulling strength can be doubled by flying two Malays in tandem.
Fig. 17.—A Malay Tailless Kite.
How to Make a Malay. Figure 17 shows a Malay kite in flight, Fig. 18 a detail of the completed kite, Fig. 19 the completed framework, and Figs. 20, 21, and 22 the details for preparing the frame sticks.
The Sticks. This kite has a vertical stick and a bow-stick, each of which should be 40 inches long, about ¾ inch wide, and 3/8 inch thick, for a kite of medium size. In the cutting of the sticks lies half the secret of making a kite that will fly successfully.
Fig. 18.—Completed Malay Kite with Belly-band Attached.
Drive a small nail or large tack into each end of the two sticks, to fasten the framing-string to (Figs. 20 and 21), and notch the side edges of the bow-stick near each end for the attachment of the bow-string (Figs. 21 and 22).
The amount to bend the bow-stick is important. For a kite with a bow 40 inches long the distance between the string and stick should be 6 inches (Fig. 21). Use a strong twine for the bow-string, and tie it securely to the notched ends.
Framing the Sticks. Fasten the bow-stick at its exact center to the vertical stick, placing it 4 inches down from the top of the vertical stick, as indicated in Fig. 19. Drive a couple of brads through the two sticks to hold them together, and then reinforce the connection by wrapping the joint with strong linen thread, crossing the thread in the manner shown.
When the two sticks have been joined, connect their ends with the framing-string. Stretch this string from stick to stick, and tie securely to the end nails. Instead of the end nails, the sticks may be notched to receive the framing-string, but the nails are more satisfactory because the string can be tied fast to them and will not slip.
Covering the Framework. The strong light-weight brown wrapping-paper now so generally used makes an excellent covering for the framework. A few sheets can be purchased at a near-by store for the purpose. You will likely have to paste together two or more sheets to make one large enough. The paper should be placed on the outer face of the bow-stick, and should be allowed a little fullness instead of being stretched tight as on hexagonal tail kites. Lap the edges of the paper over the framing-string in the ordinary way of covering a kite.
Attach the Bridle at the intersection of the bow-stick and vertical stick, and at the lower end of the vertical stick (Fig. 18), and make it of the right length so when held over to one side it will reach to the end of the bow, as indicated in Fig. 18. Tie the flying line securely at the point A (Fig. 18); then the kite will be ready for its maiden flight.
Fig. 20.—Detail of Vertical Stick.
Fig. 21.—Detail of Bow-stick.
Fig. 22.—Detail of End of Bow-stick.
Flying-Line. The kind of cord which a mason uses for his plumb-lines is splendid for flying the Malay kite. If you cannot get some balls of this, be certain that what you do get can be relied upon, because it is provoking to lose a kite which you have taken a great deal of pains in making, through the breaking of the flying line.
The Box-kite. Of the more pretentious kites, none is as popular as the rectangular box-kite.
Box-kites may be purchased ready-made in a number of sizes, but they are not cheap, and it will pay any boy to take the time necessary to make one. While their construction requires considerable more work than the single-plane type of kite, it is not difficult.
Figures 23 and 24 show a kite of scientifically developed proportions. Pine, spruce, and whitewood are the best materials for
The Kite Sticks, though any strong, light-weight wood of straight grain may be used if easier to obtain. If you live near a lumber yard or planing-mill, possibly you can get strips of just the size you require from the waste heap, for the mere asking, or for a few cents get them ripped out of a board. If not, you will find it easy enough to cut them yourself with a sharp rip-saw.
The Side Frames. Cut the four horizontal sticks 3/8 inch thick and 3/8 inch wide, by 36 inches long (A, Fig. 25), and the four upright connecting sticks (B, Fig. 25) ¼ inch thick, ½ inch wide, and 10 inches long. Tack the upright sticks to the horizontal ones 6 inches from the ends of the latter, as shown in Fig. 25, using slender brads for the purpose, and clinching the projecting ends. In fastening these sticks, be careful to set sticks B at right angles to sticks A.
After fastening together the side-frame sticks as shown in Fig. 25, lay them aside until you have prepared the cross-section of the kite.
The Covering for the End Cells. A light-weight muslin or tough paper should be used for this material. Cheese-cloth will do if you give it a coat of thin varnish to fill up the pores and make it air-tight, after it has been put on. The light-weight brown wrapping-paper now so commonly used is good covering material.
The cell bands for the kite illustrated should be 10 inches wide and 5 feet 9 inches long. If of cloth, they should be hemmed along each edge to prevent raveling and to make a firm edge. If of paper, the edges should be folded over a light framing-cord and pasted. Sew together the ends of the cloth bands, or paste the ends of the paper bands, lapping them so the measurement around the inside will be exactly 5 feet 8 inches, the proper measurement around the sticks of the finished kite.
Assembling the Kite. Slip the bands over the side frames, spread the frames to their fullest extent, and hold them in this position by means of sticks sprung in temporarily between upright sticks B. Then measure the proper length for the diagonal braces C (Fig. 26). These sticks should be notched at their ends to fit over the sticks A, as shown in Fig. 27, and they should be a trifle long so they will be slightly bow-shaped when put in place. In this way the frames will keep the cloth or paper bands stretched tight.
The notched ends of the diagonals should be lashed with thread to keep them from splitting. Lashings of thread around the frame sticks A, as shown in Figs. 25 and Fig. 27, will keep the ends of the braces from slipping away from the uprights B, which is the proper position for them. Bind the braces together at their centers with thread, as shown in Figs. 24 and 26. Coat the lashings with glue after winding them, and the thread will hold its position better.
The cloth or paper bands should be fastened to each horizontal frame stick with two tacks placed near the edges of the bands.
There are several methods of
Attaching the Bridle, but that shown in Fig. 244 is generally considered the most satisfactory. Of course, the kite is flown other side up, with the bridle underneath. The three-point attachment has cords fastened at the two outer corners of one cell, and a third cord to the center of the outer edge of the other cell; and the four-point attachment has cords attached at the four outer corners of the kite. The ends of the bridle should be brought together and tied at a distance of about 3 feet from the kite. It is a good plan to connect the ends to a fancy-work ring.
A Good Hand Kite-reel that can be held in one hand and operated by the other is shown in Fig. 28. Get a ½-lb. size baking-powder can for the winding-spool, locate the center of the cover and bottom end, and with a can-opener cut a hole 1 inch in diameter through each (Fig. 29). Then cut two wooden disks 5 inches in diameter for the spool flanges. These may be cut out of thin wood. If you do not wish to take the trouble to cut them round, just saw off the four corners diagonally, making the pieces octagonal. Bore a 1-inch hole through the center of each piece. Tack the can cover to the exact center of one disk, as shown in Fig. 30, and the can to the exact center of the other. Then fit the cover on the can, and glue a strip of cloth or heavy paper around the joint to keep the cover from working off, and the spool will be completed.
The axle upon which the spool turns is a piece of broom-handle 10 inches or so in length (Fig. 30). Bore two holes through it in the positions shown, for pins to keep the spool in its proper place. Wooden pegs can be cut for pins. For a winding handle, pivot a spool on the right-hand disk by means of a nail or screw. The inner flange of the spool handle may be cut off as shown in Fig. 28.
Both hands are frequently needed to haul in string quickly enough to bring a kite around into the wind, or to handle it when it pulls very strong, and then there is nothing to do but drop the hand reel upon the ground, unless you have an assistant to give it to. This is where the advantage of
Fig. 31.—A Body Kite-reel.
Fig. 32.—Detail of Axle Support.
Fig. 33.—Detail of Crank.
A Body Kite-reel comes in. With it strapped about the waist, it will go wherever you go, and always be within easy reach. Figure 31 shows one simple to make. The spool of this is made similar to that of the hand reel shown in Fig. 28. If, however, you wish a larger winding-spool, you can use a larger can than the baking-powder can—a tomato can or syrup can—and increase the diameter of the wooden flanges accordingly. Instead of the spool turning upon the broom-handle axle, the axle turns with the spool, so the spool must be fastened to the axle.
The axle supports A (Figs. 31 and 32) should be about 7 inches long, 4 inches wide at the wide end, and 2 inches wide at the narrow end. Cut the holes to receive the axle ends a trifle large so the axle will turn easily. Cut the connecting crosspieces B of the right length so there will be about ¼ inch between the ends of the spool and supports A.
Cut the crank stick C as shown in Fig. 33, bore a hole for the axle end to fit in, bore another hole in the edge for a set-screw to hold the stick in place on the axle end, and pivot a spool in place for a handle. If the hole in the spool is too large for the head of the nail used for pivoting, slip a small iron or leather washer over the nail.
An old belt or shawl-strap should be used for strapping the kite-reel to your body. Fasten this to the ends of the axle supports A by nailing the strips D to them as shown in Fig. 32.
Model aeronautics has become nearly as popular as kite flying, and girls as well as boys have taken to building these unique air toys.
The model aeroplane requires more work than ordinary kite construction. It also requires more patience and greater accuracy, because each part of the little aircraft must be made just so, assembled just so, and "tuned-up" just so, to produce a model which will give a good account of itself. Of course your first model will probably not be perfect. But if you do your work correctly and carefully it will fly, and the experience you have acquired will make it possible to turn out a more nearly perfect second model.
Many types of model aeroplanes have been devised, but those of the simplest form of construction have made the best showing. The majority of record-breaking models have been of one type—a triangular framework, equipped with two planes, and a pair of propellers operated by a pair of rubber-strand motors. A most successful model of this type is shown in Fig. 34, and described and illustrated on the following pages. This model has a distance record of 1620 feet made at the Aero Club of Illinois' aviation field at Cicero, Chicago, where it flew 16 feet beyond the fence of the 160 acre field. The model weighs but 5½ ounces, has 9-inch propellers of 27 inch pitch, and is in every essential a speed machine.
The first part of the model to make is the triangular
Fuselage, or motor base. This consists of two side sticks, splines, or spars (A, Fig. 35) of straight-grained white pine cut to the dimensions marked upon the drawing, with their bow ends beveled off for a distance of 1¼ inches, glued together, and bound with thread. The stern ends have a spread of 8 inches, and are braced at that distance by the separator B (Fig. 35). This separator is fastened flatwise between sticks A, and its edges are reduced as shown in the small section drawing of Fig. 37 so they will offer less resistance to the air. This piece is fastened between sticks A with brads. Separators C, D, and E are of the sizes marked in Fig. 35, and of the proper length to fit between side sticks A at the places indicated on the drawing. They are cut oval-shaped, as shown in the small section drawing in Fig. 37.
Figs. 35 and 36.—Working-drawings of Model Aeroplane Designed
and Built by Harry Wells.
This Model has a record of 1620 feet made at the Aero Club of Illinois'
Aviation Field at Cicero, Chicago.
Before fastening the separators in position,
The Thrust Bearings for the propellers, and the end plates for connecting the wire stays, must be prepared. Figure 38 shows a dimensioned detail of the thrust bearings, and Fig. 37 shows how they are bound to the ends of sticks A with thread. These are cut out of brass, bent into the shape shown, and have a hole pierced through the folded tip for the propeller-shaft to run through, another through one end for the brad to pass through that pins stick A to B, and another through the other end to fasten the end of the wire stays to. The small detail in Fig. 37 shows the end plates for the wire stays. These are made no longer than is necessary for the connecting holes for the wire-stay ends. Pierce a hole through the center of each plate for the brad to pass through which fastens sticks A to the ends of the separators. The plates are bound to sticks A with thread.
Fig. 37.—Detail of Fuselage and Motor of the Wells Model.
Fig. 38.—Detail of Thrust Bearing, Propeller-shaft, and Connections.
Fig. 39.—Detail of Bow Hook and how Rubber Motor is Connected to it.
The Bow Hooks support the bow ends of the rubber motor, and are made upon the ends of a piece of heavy piano-wire bent V-shaped to fit over the ends of sticks A (Fig. 39). Bind the wire to the sticks with thread, coating the thread with glue to make it hold fast (Fig. 37).
The Main Plane has a framework built as shown in Fig. 40, with the front or entering-edge, and the rear or following-edge, made of sticks of white pine or other light-weight wood, and the ribs and tips on the ends made of No. 16 gauge aluminum wire. The ends of the frame sticks are cut away on their outer edge, to receive the ends of the wire forming the tips, and the ends of these wires, and the laps of the wire ribs, are bound in position with thread, and the thread then coated with glue to hold it in position.
The Elevator, or front plane, has a framework made as shown in Fig. 41. Its entering-edge is a stick, and its following-edge, ribs, and end tips, are made of No. 16 gauge aluminum wire. You will notice by Fig. 41 that the center ribs cross the following-edge of the frame and are bent up in the form of a flat loop. This loop rests against the under side of the fuselage, and gives the elevator its proper angle for stability (Fig. 36). The tips are bent up to add stability.
The frames of the main plane and elevator are covered with china-silk, which may either be sewed or glued in place, and this is given a thin coat of shellac to make it air-tight and taut. The covering must be put on smoothly to reduce to a minimum what is known as skin resistance—the resistance that the plane makes to the air while passing through it.
The main plane and elevator are held to the fuselage by means of rubber-bands slipped beneath them and over the fuselage, and unlike the planes of the majority of models, are fastened to the under side of the fuselage. Figure 36 shows the approximate position of the elevator. That of the main plane will vary under different air conditions, sometimes being placed over the separator C, and at other times closer to separator B than is shown in Fig. 35. Therefore, you must adjust your plane and elevator—this operation is known as tuning—to suit the condition of the atmosphere, until you find the positions where they will give the machine the greatest stability. A great factor in the successful flight of a model aeroplane lies in properly tuning the planes, both laterally and longitudinally, and of course the planes must balance at their centers, in order to make the machine balance properly.
Fig. 40.—Detail of the Main Plane Framework of the Wells Model.
Fig. 41.—Detail of the Elevator Framework.
Fig. 42.—Detail of Fin.
The Fin directly over the center of the elevator (Figs. 34 and 36) is provided for stability, and may be used as a rudder by turning it slightly to one side or the other. It is made of No. 34 gauge sheet aluminum, cut to the form shown in Fig. 42. Its vertical edge is bent around a piece of heavy wire, as shown in the plan detail of Fig. 42, and the lower end of the wire is fastened upright between the bow ends of sticks A.
Fig. 43.—The Wells Model Propeller.
The Propellers are the most difficult part of the model aeroplane to make. They must be very accurately cut, and must be of identical size and pitch. The pitch of a propeller is, theoretically, the distance forward that it advances in one complete revolution.
Figure 43 shows one of the propellers of Harry Wells' machine, which is 9 inches in length and has a 27-inch pitch. Figure 44 shows
How to Prepare the Propellers. The pair must be opposites, that is, one must be of right-hand pitch and the other of left-hand pitch, or, in other words, the upper end of the right-hand pitch propeller turns to the right, and that of the left-hand pitch propeller turns to the left, when viewing them from the rear.