George Anthony Cavanagh

“ Problems of engineering as huge as were solved by master builders; juridical and legal questions to be decided as stupendously difficult as any Gladstone would wish them; possibilities for the development of international relations greater than were ever conceived; problems of transportation to be solved by the application of aircraft, as wonderful as any economist could wish; opportunities to gain distinction splendid enough to satisfy the most ambitious person. ”

“ In the preliminary trials of a model close attention must be paid to the few structural adjustments that will be found to be necessary and which if not properly and quickly remedied will result in the prevention of good flights or even in possible wrecking of the model. Careful designing and construction are necessary but it is equally as important that the model should be properly handled when it is complete and ready for flying. ”

“ With clubs of this size a director is not needed as the affairs of the club are usually entrusted with the governing officers, the President, Treasurer and Secretary. In as much as the constitution and by-laws are an important factor in the affairs of any model club, the governing officers, before mentioned, should hold a private meeting at the earliest moment whereat to frame a constitution and set of by-laws embodying the purposes and policy of the club. ”

“ When the propellers have thus been mounted the one-half inch of shafting which extends out from the hubs of the propellers should be bent over to grip the propeller hub and thereby prevent the shaft from slipping during the unwinding of the rubber strands. For the reception of the rubber strands to provide motive power a hook must be formed in each shaft and this can be done by holding securely that portion of the shaft which extends toward the point of the model, while the end is being formed into a hook as illustrated in diagram 7. ”

“ It is equally unwise to attempt to fly the model in a garden in which there are numerous obstructions, such as trees and so forth. A wrecked model is very often the result of such experimenting. The safest way to determine the flying ability of any model is to take it out in an open field where its flight is less apt to be interrupted. ”

“ One ring only is used in connection with the pistons. The cylinders have a bore of 11⁄32′′, with a piston stroke of 7⁄16′′. In view of the fact that pull rods show a greater tendency to overcome centrifugal force, they are used instead of push rods to operate the valves. The crankshaft has but one post, which is uncovered in turn by each inlet pipe as the engine revolves. The “overhang” method is used to mount this engine to the model. With the exception of the valve springs, the entire engine, including the mounting frame and tank, is made of brass. ”

“ During all of the foregoing operations it must be clearly borne in mind that the Top of the blank propeller must always face upward, and the cutting should always be done on the Straight lines. Should the straight edge be cut on one edge of the blank propeller and the curved edge on the other, it would result in the blades of the finished propeller having a tendency to push in opposite directions and in consequence no propulsion of the model would be possible. ”

“ As all other parts of the model are attached to the frame in addition to its having to stand [22] the strain of the tightly wound rubber strands which serve as the motive power for the model, it must be made strong. It is therefore necessary to exercise care and judgment in making certain that the different units that make up the frame are rightly proportioned and are of the proper material. ”

“ Having satisfactorily developed the hand launched model and the model rising off the ground under its own propulsion the constructor will next turn his mind to the question of having his model rise under its own power from the surface of the water in the fashion of passenger-carrying hydros and flying boats. This will be accomplished by the use of pontoons attached to a specially designed chassis. ”

“ A U-shaped wire is bound to the outrigger beam and frame. A single diagonal strip of bamboo is also fastened to the outrigger beam with a brad, its upper end being bound to the cross bracing of the frame, making a very solid connection.
Under ideal weather conditions this model will fly on 12 strands of rubber with the possibility of a better duration than has been made. But, however, with 15 strands the model will [69] rise at every attempt. More rubber, however, causes the bow of the boat to nose under and to accommodate this increase of power the boat should be lengthened. ”

“ Only two sets of uprights separate the wings, thus adding to the streamline appearance of the machine.
Both tail and rudder are double surfaced and are built entirely of bamboo for lightness, the tail being made in the form of a half circle measuring 12′′ by 8′′. Steel wire is used on the construction of the landing chassis, the chassis being so designed as to render it capable of withstanding the most violent shock that it may possibly receive in landing. The propeller used in connection with the model is 14′′ in diameter and has an approximate pitch of 18′′. ”

“ Just as in the large sized aëroplanes there are many types of bodies, so there are many different types of frames in use in model construction, but the standard, and for all practical purposes the best frame, resembles the letter A in shape, hence the name A type. The lightness of the frame depends entirely on the materials used and the manner in which it is constructed. ”

“ The development of the compressed air engine has given an added impetus to model making, necessitating more scientific experimenting and developing the art of model flying along lines of greater value to those who may eventually take up the work of building our future air fleets. ”

“ Although of peculiar construction, the Wise rotary compressed air engine offers a very interesting design from a viewpoint of ingenuity. This engine embodies a number of novel features not hitherto employed in the construction of compressed air engines, and in view of the fact that the majority of compressed air engines are made on the principle of the opposed type, this engine suggests many possibilities for the rotary type engine. ”

“ Although numerous model constructors in America are experimenting with model gasoline engines, the Midget Gasoline Engine, the product of the Aëro Engine Company, Boston, Massachusetts, is perhaps the most satisfactory up to the present time. ”

“ The propeller is driven by five strands of 3⁄16th′′ strip rubber at about 760 r.p.m. when the model is in flight. At the time when the model made its record flight of 116 seconds the rubber was given 1500 turns which is not the maximum number of turns. At other times the [63] model has flown satisfactorily with less turns of the rubber. While in the air the model flies very slow and stable notwithstanding its light weight and large surface. On three occasions the model has made durations of approximately 90 seconds which rather dispenses the possibility of its being termed a freak. ”

“ In preparation for launching, the model should be held above the head, one hand holding it at the center of the frame, the other in the center of the propeller brace in such a way as to prevent the propellers from revolving. When the model is cast into the air if it is properly adjusted it will fly straight ahead. ”

“ A precaution which is sometimes worthy of attention before the launching of the model under its full power is to test out the propellers to find out whether or not they are properly mounted and whether they revolve evenly and easily. ”

“ After having constructed an engine as has just been described, the constructor may find it to his desire to construct a different type of engine for experimental purposes. The constructor therefore may find the descriptions of satisfactory compressed air engines in the following paragraphs of suggestive value. ”

“ Bamboo about 1⁄16′′ square is used to obtain the outline of the wings. The main wing has a span of 33′′ with a chord of 51⁄2′′. Split bamboo is used for the making of the 9 ribs. The wing spar or brace is of spruce 3⁄16′′ × 1⁄8′′ and is fastened below the ribs as illustrated in diagram 13. The elevator is constructed in like manner but has a span of only 17′′ × 43⁄4′′ and has only 5 ribs. A block 3⁄4′′ high is used for elevation. Both wings have a camber of 1⁄2′′ and are covered on the upper side with silk doped with a special varnish and a few coats of white shellac. ”

“ The two long bolts that hold the steel caps on either end of the tank also serve as attachments for the spars that hold the tank to the engine bed, as shown in diagram 17. The tank has been satisfactorily charged to a pressure [101] of 200 lbs. per square inch, but only a pressure of 150 lbs. is necessary to operate the engine. The tank measures 10′′ in length by 3′′ in diameter and weighs 7 ounces.
The wings of this machine are single surfaced and covered with fiber paper. The top wing measures 42′′ in span by 6′′ in chord. ”

“ Each flyer will be allowed but one model and shall be entitled to three official flights, but he shall be permitted to make any repairs or [138] replace any broken parts. No contestant shall be privileged to fly a model not of his own construction. Each event shall close when all the contestants have made three official flights, or when three hours’ time has elapsed.
[139]
WORLD’S MODEL FLYING RECORDS (Twin Propeller Pusher Type Models)
monoplane
Year 1917. ”

“ In this part of the work great care is to be exercised for by the time the necessary cutting has been done on the back of the propeller the entire structure is very fragile and one excessive stroke of the knife may result in destroying the entire propeller blade. By constantly holding the wood to the light it is possible to determine with a reasonable degree of accuracy the evenness of thickness. To complete the Bottom side of the propeller the blade should be sandpapered as was the top. ”

“ Each competing club must be represented by a team of three contestants and one non-competitor, who will act as judge in conjunction with the judges from the other clubs, and a manager selected by the judges who will supervise over the entire tournament and issue calls for meetings. ”

“ Some model flyers use but a single stick for the frame, but generally the A type frame is preferred for the reason that it is more durable, the wings can be more securely attached to it, and that it is possible of developing very much better results. ”

“ As a matter of fact, there are already in active life, contributing their share to the development of aëronautics, young men who only a few years ago competed for prizes which the writer offered for model competition. ”

“ Mast—A perpendicular stick holding the stays or struts which keep the wings rigid.
Model Aëroplane—A scale reproduction of a man-carrying machine.
Mechanical Power—A model driven by means other than rubber strands such as compressed air, steam, gasoline, spring, electricity and so forth is termed a mechanical driven model. The power used is termed mechanical power.
Motive Power—In connection with model aëroplanes a number of rubber strands evenly strung from the propeller shaft to the frame hooks which while unwinding furnish the necessary power to propel the model. ”

“ The engine consists of five cylinders and weighs four ounces, including the propeller and mounting frame. On a pressure of 15 lbs. the engine will revolve at a speed of 1000 r.p.m. The connecting rods are fastened to the crankshaft by means of segments and are held by two rings, making it possible to remove any one [104] piston without disturbing the others. This is done by simply removing a nut and one ring. The crank case is made from seamless brass tubing, into which the cylinders are brazed. The valve cage and cylinder heads are also turned separately and brazed. ”