Model Wright aeroplane. Model Bleriot aeroplane

Spring motors may be used to drive the propellers ,- they are not shown in the model illustrated (Figs. 18, 19) or in Sheet No. 4. Two motors are required, one to drive each propeller, one motor should run in the opposite direction to the other. As it may be difficult to procure two motors, one running in the opposite way to the other, then both must run the same way and drive the propellers in the same direction, as is done in some of the large flying machines, but not in Wright’s. Each motor is fixed between the decks in front of the diamond frame which carries the propeller spindle. The motors are fixed (in the centre line of the deck) so that the square rod, for the winding keys, project downwards through the tin plates and the lower deck, and in this way the springs are easily wound up, but make the holes as small as possible through which the rods pass. The spring frames must be firmly soldered (being provided with lugs) to the plates on which they rest, to the front of the diamond frames, and straining wires can be run to attach them to the main spars of the upper deck.

When the several parts are finished, such as the elevators, main decks, and rudders, they must all be covered over with some material such as linen, tracing cloth, or oiled silk, but the best of all is the thin fabric material sold by the model makers (special AA at 1;. 9d. per yard). All these parts should be covered over before being put together . The real machine has a double covering put on, and so has the model shown in Figs. 18, 19, but this will, to some extent, increase the weight and also add to the labour of the amateur, so that one side only may be covered over.

After the decks are joined together, cover the top side of the upper deck or plane, cut the fabric say 53-inch larger than the part to be covered, draw it tightly over so that it lies evenly on the ribs. With scissors make slits from the edges of the material inwards to each strut, so that it will fold underneath between the struts, pull the material well over the front spar and ends of the ribs, fold the edges underneath , then glue or sew it to the framework and to the ribs, so that it follows the curvature of the latter.

Diagonal straining wires, or even lint threads may be used as stays between the decks, and these will improve the appearance as well as strengthen the parts (Figs. 9, 10 *). Underneath the lower deck, instead of a wheeled chassis, are placed two runners or skates ZY (Figs. 7, 9, IO *) which take up the shock in descending to earth. In the model they are rigid. Take two pieces of wire, each, say, about 15 inches long. To the cross stays, underneath the lower deck, fix with binding wires, and solder, four vertical short struts UVWX (Figs. 7, 9, IO *) ,' having angled the ends as before, the planes now seem to rest on four legs. To the angled ends of U, V, on one side, wire and solder on a skate. In the same way fasten the other skate on the other side, the rear ends of both skates project a short way only behind V and W respectively. Bend the front parts of the skates upwards (Fig. 7 *). These carry the elevators at their extremities. The skates are joined together by two tie rods CT, each is joined to the upper deck by two tie rods A’B', to the lower deck by two slanting tie rods, and to the under surface by one vertical and two cross tie rods, besides the vertical struts UVWX.

The flying machine having been put together and made as light as possible, consistent with strength, it must be carefully balanced so as to remain on even keel, or horizontal , when in flight, and the centre of pressure should fall exactly over the centre of gravity. Suspend the machine from the centre of the top plane by a piece of string tied to a fixed point above it (as a gasalier or a hook in the ceiling), in order to test if it be evenly balanced 01 tends to fall to one or other side, or has a tilt or dip anteroposteriorly . As it will likely be out of balance, put narrow strips of lead as ballast underneath the main planes or elevators, in fact, anywhere where required, and bind them on with fine wire (hot solder would burn the coverings), if necessary little bits of the lead can be cut off to give proper balance so that the machine hangs level.

Having obtained correct balance, remove the machine and take it out of doors to test its flying capabilities. Wind up both motors (which should have catches to prevent the propellers from revolving) with the right hand and hold the machine on even keel so that the propellers will not strike against the hand, and with the left pull the elastic bands which release the spring catches and at the same time throw the machine off the hand with a straight forward throw, then (after a little practice) on giving the machine a proper forward impetus it will fly for some distance before the energy of the spring is exhausted and it falls to the ground.

This model might be stronger and more easily made by the amateur if constructed of wood and cane or split bamboo in a similar manner to that on p. 78. It can be constructed (Fig. 12 *) without the rudder and with one propeller only, there being only the main decks and elevators with an elastic motor, the elastic being stretched on a long frame, constructed like that given on p. 52, but stronger (of ash or oak) and quite separate from the main decks and elevators, which are fastened to it by screws or binding wires.

One large propeller, say, 8 inch diameter, made of thin wood and steamed (see p. 56) is fixed in the antero-posterior centre line of the lower deck, provided with a hard drawnbrass spindle terminating in a hook. This revolves in a sheet-brass bearing screwed to the end of the frame. At the opposite end, under the elevator, is placed a fixed hook.

Suppose the distance between the books is 1 foot 1 inch, then to drive this propeller we require 6 feet 6 inches, or, 7 feet of% inch elastic to allow a skein, consisting of 6 strands to be used. This amount is ample to allow of long pieces to tie the knot firmly at the ends of the skein. A rudder can be put on, but the outriggers which carry it would require to be four in number, two at the top and two at the bottom, these would pass out from the rudder as one piece at the top, and as one at the bottom, slant outwards and be fixed to the decks, so as to keep clear of the rudder when revolving. Instead of one motor, two geared elastic motors can be used.

So 32 ozs. is the total weight which theoretically the planes will carry, but to get good results it must be considerably under this weight, say 20 ozs. In this model there is no wing warping device as in the real flying machine, because this arrangement would complicate the parts somewhat and serve no useful purpose, it cannot be used during flight, and this is why we have omitted it.

The areas given in the sheet of working drawings are those of the double decks and elevators. The shading is done to represent the parts that are covered over with fabric or cloth. In this sheet Figs. II and 12 are not drawn to scale.

Model Bleriot's aeroplane (monoplane type)

Bleriot’s flying machine will interest our readers as it was on this type of machine that he successfully flew across the English Channel. It would not be difficult to construct a working model of this flyer, as it has a single instead of a double deck, and this means less work in constructing. Through the courtesy of the proprietors of Flight we have again been permitted to take a few notes, and copy from the working drawings of the Cross-Channel flying machine, and so we are enabled to give working drawings, on Sheet No. 5, at end of book (containing as well a few original drawings of our own), for constructing this model. Like the last, these drawings are not accurately to scale in every detail, but the overall dimensions are about right, and the model will closely resemble the real machine; our object being to build a model that will really fly and not one to put under a glass case and be exhibited.

Any amateur who has successfully made either or both of the models described on pp. 58, 65, should find no difficulty in making this flyer. It is the only example (except the toy model, p. 51) we give of a machine of the monoplane type. It is simpler in construction than the biplane, there being only one deck or pair of wings, as the main frame divides the deck in the centre, and this causes each half to jut out like an extended wing from the body.

lower member to its under surface. The middle spar keeps them apart, and both join with a taper at the rear, so as to present a narrow edge, the aft spar being glued between them. In this way the deck has a smooth surface both on top and bottom when covered over. It would be less work to make the wings “single surfaced” as in the case of the Voisin machine, and this would also make them lighter, then the front edge of each rib, if made of wood, would be carried flush to the front edge of the front spar and be bevelled on the under surface to lie on it (see Sheet No. 3, Fig. 15, at end of book). The shoulder of the wing is square with the sides, the extremity could be left square also, but, if modelled after the original, it must be of a circular shape (Fig. I The circular shape is got thus : take a piece of wood, say, 1 inch thick, cut it to the proper outline for a mould. Take a piece of white pine 2’ 2” X 17—6” X 'liG”, steam, bend and tie it to the mould, when set, check it into the end of the front spar, do the same aft till it is flush with the whalebone, join parts with glue and binding wire. Short ribs are attached to lie flush with the other ribs. The wings should be “double surfaced " with cloth, zle. covered over on both sides, thus encasing the ribs and making both faces smooth. Light fabric material is the covering used, a piece, say, 2 feet 6 inches by 2 feet 5 inches will be ample for a double surface. The wing is mounted thus : the front spar juts out from the shoulder of the wing for 1}; inch and this spigots into an aluminium or magnalium socket of a hollow rectangular shape screwed to the side of the upper girder spar (see Sheet No. 3, Fig. 1 1, at end of book). When in place the joint can be secured by a wood screw put through the socket. The hind spar enters a similar socket (attached to the under surface of the rear spar or to a strut) and is screwed to it. Thus it is easy to dismantle the machine and remove the wings by taking out the screws. The other wing is made in the same way. They both stretch out horizontally from the main framework, and are rendered quite rigid by four supporting steel or magnalium wires which pass to each wing, two above and two below, being attached to wood screws or to brass clips which are fastened to the spars. The wires are attached on the body frame to brass or magnalium tension struts screwed to it and by means of strainers the wings are kept absolutely rigid and properly flexed. There is no wing warping device.

The supplementary plane or monoplane tail T (Figs. 1, 2, 3 *) is mounted underneath the girder frame. The central portion is rigid during flight, but can be adjusted in respect to its angle of incidence by means of an arrangement for controlling the pivoted tips. We have omitted these devices here, as they cannot be used during flight. The tail is similar in construction to the planes, and are pivoted to be independently movable for purposes of control in the real machine. Bleriot controls the lateral balancing of his flyer by warping the main wings, while the tips of the tail— which work together—perform the usual function of an elevator.

Tail and flfr.——The tail T and the tips TE are both double-surfaced, the ribs having two members, one above and the other below the spars. In T there are seven ribs, the two outer members (Fig. 4 *) (the lower member should be curved instead of flat) have a small plate of sheet brass screwed between them, which has a hole for the wire spindle on which the tips pivot. The % inch spindle is pushed through from one end, and must be at least 23% inches long. Each tip TE is made in the same way, and contains four ribs, each consisting of two members, the rounded tip made in the same way as the rounded tip of the main plane is constructed (see p. 91). The spindle passes through the small plates in the same way. When finished TE is put on the spindle, and a nut prevents it from coming ofl’. If the tail and the tips have the ribs made single-membered, then the two outer ribs of T, and the two inner and two outer ribs of both of the tips TE would be made thicker where the spindle passes (Fig. 7 *) through them, and a small plate would be screwed to the outside of each end rib. Nuts, put on the ends of the spindle, prevent the wing tips from coming off. A washer can be put on the spindle on each side between T and TE to act as a distance piece. The tail is covered over with fabric material in the same way as the wings. If they are double-surfaced the material required will be, roughly, for T, 1 foot 2% inches by 1 foot, and for each tip 1 foot 2% inches by 7 inches. If the tail and tips are made single-surfaced, then they can be covered on the top side only, and much less material will be required. The overall space of the tail, including the tip, is approximatelyé that of the main wings, the area is about i as great, and the individual area of the tips is about 11*- that of the full area of the tail in the real machine. Four short supporting wires fastened to the upper spars of the girder frame pass outwards and support the tail (Fig. I *).

The tail is fixed, underneath the girder frame, to the longitudinal spars, by two screws on each side, which pass through the main spars. A little piece of wood can be cut to a taper shape, one for each side, and be glued between the girder-main spar and the top of T, in order that the tail should be set as shown (Fig. 2 *), having the front edge raised above the rear edge, and this latter is further attached to the girder frame by means of a straining wire.

The wings must also be fixed so that the anterior edges are higher than the posterior edges (see page 111). The correct angle to set the tips at for ascent is found out by experiment , each tip is set separately, but at the same angle. A piece of elastic cord, tied to a small hook, is fixed on to the upper spar of the frame (just above the tail), and passes to a clip (Sheet No. 3, Fig. 17, at end of book), this being fixed to the front spar of TE, will elevate TE. While another elastic cord, attached, on the upper surface of TE, to the rear spar, passes backwards and inwards and is tied to a small hook on the outside of the lower girder spar, this last will raise the rear of TE, and keep the tip tilted. By tightening one cord and slackening the other one, various degrees of tilt may be obtained for ascension. The elastic cords may cross each other.

ClmniL—The chassis consists of a pair of tubular brass columns BC (Fig. 5 *), one on each side, attached together by two wooden cross spars, and also by a brass wire tie rod near the foot. Each column is 8% inches long, of inch tube, and passes through the wooden spars, AS, AS’, each spar is about 9% inches by; inch by}; inch. The upper spar AS, through which BC passes, is fastened by glue and sprigs (small brass angles would make a stonger joint) to the front ends of the top longitudinal spars of the girder frame, the lower spar AS’ is fastened to the front ends of the lower longitudinal spars. The column BC passes vertically through each cross spar near to its extremity. A collar C is soldered to the tube just above AS’. A nut N is threaded on the top of BC just over AS, thus BC cannot slip out of AS when N is put on.

Two light brass sliding collars SC, SC’, with holes drilled diametrically opposite for pivoting screws, should be passed over BC before fixing in place. There are two upper wheel forks, each, say, 8 inches long (of brass wire), flattened out at the upper and lower extremities. One is pivoted on . each side of SC. Two smaller forks, 3‘5 inches long, are pivoted, one on each side of SC', these together form the four wheel forks, and must be bent sufficiently far apart to allow the wheel getting in between them, and revolving without striking them. The forks are soldered together at their extremities, and are drilled for the axle to pass through them.

Wheels.——The wheels are cycle rubber tyred, say, about 4 inches diameter, and can be fixed, both on separate axles or on one axle, but if the latter, then the axle must be pivoted as described on page 75, and illustrated in Fig. 13, Sheet N o. 3, at end of book. As the collars SC, SC', are free to move on the column, the wheels will have a certain amount of rising and falling movement. The wheel fork, of the opposite side, is constructed in the same way, and is set at a distance of 8 inches apart.

In the real flying machine the collars SC, SC’, are anchored to the lower ends of the columns by a pair of strong elastic bands, and these form the suspension. Elastic bands can be used in the model, but two light spiral springs might be preferable (Fig. 5 *). If this method be adopted then the wheels will rise and fall over uneven ground as the collars rise and fall on the columns. It will be seen (Fig. 3 *) that the columns are joined together in front by three tie rods, the tWQ upper being wooden spars, and the lower one a brass wire, which makes a pivoted joint with BC, as the stud which is screwed into BC passes loosely through a hole in the end of it. A tension wire, one on each side, passes from the extremity of the brass tie rod upwards and outwards to the under surface of the wing, near to its outer extremity, and is fastened to a clip on the front spar; while the rear straining wires from the wings are attached to the centre of the V-shaped tension strut underneath the girder frame (Fig. 2 *). The tie rod RR, 7% inches long, of thick brass wire, has a flat hammered on it at both ends, and then is bent at the neck of the flats, as shown in Fig. 5.‘ The flat ends must be neatly finished off, and the stem of the rod filed down to diminish weight.

Through the centre of the lower flat a hole is drilled for a inch stud (which must be an easy fit), and the other flat is drilled for a wood screw. A TaE inch stud is, after passing through the lower flat of RR, screwed into BC at its lower end, and if not screwed up too tight this forms a pivoted joint for the castor-hung wheel. The stem of RR slopes upwards and inwards, and joins the correspond— ing rod from the wheel column on the opposite side, near to the centre of the transverse line of the girder frame (Fig. 2 *), and both rods are screwed to one of the bottom cross spars.

Rear Wheels.—There is only one rear wheel, placed in front of the tail T in the centre line of the girder frame, it is fitted up similarly to that described. There is a vertical column of brass tubing T (Fig. 6 *), say 6} inches by % inch diameter (outside), the stem passes through a stiff sheetbrass bracket B' screwed between the two top spars of the girder frame to a cross spar in the centre line. Two forks of sheet brass or of brass wire (made with flats at the ends, as already described), say, 6 inches long, and other two shorter ones, each, say, 3 inches long, are pivoted through the brass stem (Fig. 6 *), by pivots (made of copperwire rivets loosely riveted). The forks are bent apart to let the wheel in between them. The wheel is a rubber-tyred cycle wheel, say 2 inches diameter, which revolves loosely on its axle, this last is soldered by its ends to'the forks outside.

A tie rod RR joins the lower extremity of T to the girder frame, a small stud passes through the central hole in the flat at the end of RR and is screwed into the bottom of T, this forms a pivoted joint. The rod slopes upwards, and by means of a flat on the opposite end, it is firmly screwed to the under surface of the girder frame. At the top end T has a nut screwed on, which bears against H, while underneath a spring passes between B' and an abutment A (a small nut), soldered to T. RR will yield slightly as it is pivoted to the end of T, while the upper part of T bears against the spring Sp. It will be seen that the wheel has a slight rising and falling movement and a swiveling motion around the pivot. Another fork might be attached to the wheel forks in front, which carries an eye or a small hook at its extremity, and two elastic cords EB can pass from this hook, diverging slightly, and each be fastened to a small hook attached underneath the frame, one on each side. The rubber, when stretched by the wheel turning to one side, will, by its recoil, bring back the wheel to its normal position on the weight being removed.

The girder frame is covered over with thin fabric material, put over the bottom and both sides for a distance of 16 inches from the front extremity. The material should be put on separately on each surface and have its edges cut flush with the edges of the frame. For the bottom we require a piece 1 foot 4% inches by 5 inches, and for each side 1 foot 4!; inches by 5 inches (roughly), 1 foot 5 inches will cover the top surface.

On the top of the girder frame, between the wings (Figs. 1, 2, 3 *), and fastened by screws to the spars, are four A-shaped pieces of sheet brass which carry a wire rod between them soldered to their apices, these form tension struts, a similar one is placed underneath; these support, as already mentioned, the wings by means of straining wires, which pass to their upper and lower surfaces and retain them in position.

The rudder R (Figs. 1, 2, 9 *) is made of wood cut to shape shown, ,‘f inch thick at the front edge, and tapering to 535 inch at the rear, it is smoothed all over and the edges rounded off. It is attached to the stem post SP (Fig. 9 *) (which is rounded) bya piece of sheet brass, forming a hinge BH, which partly encircles SP, and is screwed to both sides of the rudder. The latter can be made a fixture, or is moved by means of a small horizontal lever in front attached to it, and which has two pieces of twine passing, one on each side, to the main deck and terminating in the aviator’s hand lever.

The propelleri P (Figs. 2, 8 *) is a wooden one in Bleriot’s flying machine. In this model it may be constructed of wood, sheet brass, aluminium, or magnalium; as regards the blades, if made of metal, these are riveted to brass arms which attach them to the boss. A wooden propeller (Fig. 8 *) might be sawn out of the solid and then cut away and filed to shape shown, or made of thin wood, steamed and bent to shape, if so, it should be thickened at the boss by pieces put on and glued, one to each side, two small sheet-brass plates can be screwed, one on each side, and have holes drilled through them corresponding to the central hole in the boss. A shoulder should be made on the % inch spindle by filing, and a nut on the end makes the boss abut hard up against the shoulder, then a little solder will fix the propeller firmly on the spindle. A two-bladed propeller can be 11 inches diameter and 1% inch wide, but the best size of blades to use must be found out by experiment.

The blade must have the sharp corners removed from the extremity, should be thickest in the centre and taper to the fore and aft edges. The entering edge should be slightly convex from base to tip (Fig. 8 *), and the aft edge be left straight to near the tip. A spring motor can be used to drive this flyer. The larger size, mentioned on page 117, might be suitable; it is fixed in front of the pilot’s seat, near the front of the girder frame, as the propeller is fixed in front of the machine. The motor must be firmly screwed down through a flange to the floor of the girder frame, extra spars being put across for it to rest on if required.

An electric motor could be used to drive the propeller, as this flying machine would be able to carry a small battery. If an elastic motor be adopted then the propeller is driven by three columns of elastic geared together as described on page 63. The gear wheels can be purchased, one is fixed on the propeller spindle and the other two, one on each spindle. The bearings for these spindles are drilled through a plate which is screwed to a front cross spar. At the rear of the body, in front of the aft wheel, a small plate is fixed to a cross spar, and this plate has three hooks fixed to it; the central hook being in line with the propeller spindle. Between each pair of books there passes a column of {’3 inch elastic containing four strands. If_ the length of each column be 2 feet, than the elastic contained in it will measure roughly about 8 feet 8 inches.

When completed, the machine must be properly balanced, so that it will remain on even keel, when suspended over its centre of gravity, before any attempt is made to fly it. Lead will be the best thing to use for balancing purposes. The area of the wings with that of the tail will amount to not far short of 5 square feet, so that the machine must be made much lighter than 5 lbs. in weight, the lighter it is constructed the better.

Should the propeller drive the machine along a smooth floor and yet no attempt is made by it to rise into the air, then a stronger motor must be adopted to drive the propeller at a much faster speed, or a smaller propeller must be used, or the total weight must be reduced. If still unsuccessful alter the angles of the planes, for the lift increases in direct proportion to the angle of inclination and varies as the square of the velocity. A very slight decrease in speed diminishes the sustaining force of the air upon the planes.

In Sheet No. 5, Figs. 4, 5, 6, 7, 8, 9 are not drawn to scale. A model constructed to double the size of the above will give more satisfaction and is easier to handle. Dimensions : Make the wings, each 4 feet 4 inches by 2 feet, the body 6 feet 10 inches by 8 inches, square at the front end, the tail and tips 3 feet 11 inches by 11 inches. The area of the wings works out at about 17%, square feet, and that of the tail 3% square feet = a total of 20% square feet, and, by the rule already given, the total lift would be over 20 lbs. Use a 1 foot 3 inch wooden propeller, and we think that the small petrol engine, described on page 1r9, might be suitable as a motive power. This will make a perfect model in every way. The main spars can be constructed of ash, or beech wood, bamboo, with aluminium or magnalium should also be used. The frame must be made strong to support the engine and withstand the vibrations of the propeller and engine. When finished, the fabric should receive a coat of varnish to preserve it.