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Aviation History
1913
1913 - 0659.PDF
JUNE 21, 191 -. power to further such a scheme. Some ot our readers may also »* some'lunS t0 say ™ the views expressed by our correspondent. Mr. K. \ Tivy (Bristol Aero Club, Model Section) writes: "I am much obliged to you for giving my reply to Mr. Brasnett's L former J letter a prominent place in your columns, and also for your remarks thereon. I am inclined to think that direct investigation l/OGHTJ (1) The gears were "overhung" instead of being supported by bearings on both sides. The gear wheels were not strong enough for more than i\ at. of rubber, and were mounted on Id S.W.tt, shafts which proved much too weak. 1 can only recommend th.»sr who are thinking of using gears to have them made to their design by a firm which specialises in gears. Messrs. Bonn and Co. |* A" » 1 1 1 1 1 1 1 . 1 t 1 2* 1 1 GLIDER QUITE FLAT 2 CNTELRING CDGE. STRAIGHT WITH DOwN-TURfNtlDTlPa 3 V7 CLlDERIN 3AME1 POSITION ASBLFORL BVJTWITM UP-TURNHD TAIL GLIDER WITMI"P-TI)RNCDT|R5 6 DltiCORAL ANGLE" AND UP TURNED AMD DOvVN-TURNLD WING-TIPS,WITH BALANCERS EACH SIDE Or TAIL TURNED DOWN TO STEER IN THIS POSITION IT GLIDES BLRUTIFULLY WITH THE WIND could be made with scale models as gliders and fitted with electric motors. I have heard of two *uccessful trials with electric motors, one using a flexible wire to the battery, and in the other case a flight of over 700 ft. was made with a scale model of the Bristol monoplane eighteen months ago, carrying the battery on board. " I shall await with interest criticisms of my remarks, and will write you again about a scheme of prizes for research work which I have drafted for the committee when this has been discussed." Referring to Mr. Tivy's statement re a 700 ft. flight with a scale model propelled by an electric motor, &c, we presume he is referring to a glide made from a kite, or at any rate from a high altitude, as such a motor is al>out the very worst ]x>ssible type which one could select—even with the lightest constructed bittery practi cally short circuited for the occasion. Some Experiments with Paper Gliders. By JAMES Moss. The following is a short account of some experiments that I have made with paper gliders. I should just like, however, to state that they are not the outcome of articles which have appeared in FLIGHT, but deductions drawn from watching the gulls at London Bridge. The shape of the glider is that of a gull when gliding. At first I launched the glider flat, and found that whilst the air was calm it glided nicely, but as soon as the wind caught it, it would turn against it and rise—rocking badly all the time. The next test was to turn the wing tips, when I found that it glided for a short distance, then suddenly sideslipped on either one wing tip or the other. This I attributed to the wing tips forming an inverted dihedral angle, i.e., opening downwards. My next test was to leave it as it was in the first case, but turn the tail up. In this position it glided a short distance, but was very quickly upset. The next test was to turn the wing tips and tail all up, but in this position it was very rocky when gliding. The last test was to give it a slight dihedral, i.e., to turn the tips down and up respectively, and to cut two balancers out adjoining the tail to steer by. In this position it glided well and flat, turning against the wind (when launched with it), and, rising, glided away at a great height. Dimensions, £-c.—Take a light piece of notepaper, 8 ins. by 275 ins. (see diagram), and fold over one edge a quarter of an inch, three times, leaving the breadth at 2 ins. Next fold along the centre end to end, and cut out the shape shown in the sketch. To cut out the design, cut down one-third of the breadth from the leading edge to 2 ins. along the leading edge, thus cutting out an angular shaped piece. Then cut out the shape from where you began the angle, making the wing tip an inch wide, and the main wing i °f an 'nch w'lh the overlap. The tail should be in. where it joins the body to I '25 ins. at the base. The balancers should be cut in. wide, being the running on of the tail. Mr. R. V. Tivy's Olympia Model. The following are the chief particulars of the above model, illus trated in May 31st issue :— This machine was rather a makeshift, as the " Weiss " monoplane designed for the Olympia Show was not completed in time, but will probably be shown at the Model Engineer Exhibition in October. The dimensions were : Length 36 ins., spread (upper main plane) 36 ins., chord 6 ins., surface 34 sq. ft. ; weight of machine 18 ozs., of rubber 2 ozs. ; tractor-screw 12-in. diameter. The machine has been abandoned without trials on account of errors in design as follows :— have made me a geared motor with two tin. wheels which 'rum excellently with 3 ozs. of rubber. The friction in this case is negligible. (2) I Inn! a four-bladcd 12-in. tractor (i.e., two lain, propellers clamped together) necessary and very satisfactory on a model of this size, and a much better thrust is obtained. (3) In the tractor biplane a "motor rod " was used, but 1 find that this is a great nuisance, and quite unnecessary, as the rublier can be pushed into the covered frame by means of a stick, which is withdrawn when the tail hook is fixed. (4) The wings were covered with doped cotton instead of silk, and their weight (8 ozs.) more than counteracted any advantage* which may lie obtained by employing abnormally large biplane surfaces. (5) The tail was specially designed to " camber" automatically,* when its angle of incidence was changed. Now that machines are designed to vary their speed by flying at different altitudes, the necessity for an organ of control which is efficient at more than one angle of incidence will In- appirent. There is one thing I have found with my large single screw models with geared motors, and that is that the torque when two skeins of rubber turn in opposite directions is inappreciable. Using a four- blade 12-in. tractor ami i\ o«. of rubber, " 3r " of ruddering will keep my " Weiss " model on an even keel and straight course. The " Weiss" rudder, Wing above the centre of gravity, has, of course, a " twisting " effect, which oppom the torque of the single screw. [* It should l>c interesting to know exactly how this wan done.] ® ® ® ® KITE AND MODEL AEROPLANE ASSOCIATION. Official Notices. British Model Record*. "'•"•"«'« ~ SS Ofl8rolnd .Duration Hydro, off water ... Duration Single-tractor tcrew, f Distance hand-launched ... t Duration Do., off ground ... Duration Competitions.—On June 14th the first hydro-aeroplane competition of tin season took place on the Welsh Harp water, Hendon, for the president's (Sir |ohn Slielley) prizes. Il was most successful, 19 out of si competitor* who entered competing. The number of entries was good, considering il was open t.. members only. Although the weight was for models over 4 on. in weight, i!« average weight was 8 ozs., some even weighing over 16 ozs. The judges were Messrs. k. M. lialston (vice-president) and H. H. Groves, and Messrs. Doi'lge (Hendon club) and the hon. secretary, clerks of the course. i»t prize, £%! and, £1: 3rd, £1 (presented by the president), and certificate of the association. The following were the results of the fust in competitors (maximum marks loo) :— Machine. Duration. Marks Eagle mono, ill! ... 44! sacs. l-I-JPO i-i-jr-o Canard-type mono. Water Gnat mono, iiragg Smith biplane D.A.P. mono. ... I Iragon Fly mono. Ptt.^nix t-i-i»9-<» o-j-i-Ps ... ... Mann mono. Htrmac mono. ... The prizes were presented by Mr*. W. H. Akcburst on behalf of Sir John Shelley, who was unable to be present. The hon. sec. read a letter from Sir John regretting his absence, and he stated that he would forward the vote of .. R. Lucas ... .. A. F. Houlberg ... (i. Rowlands... ... J. E. I«uch ... ... F. Wbitwortb .. F. 0. Hindsley .. J. K. Louch ... .. I.E. Louch... „. 390 yards. ... (9 MCS. ass yards. ... 68 sacs. J7 sec*. ... 173 ywd*. 68 sacs. .. 45 sec*. Place. Competitor. K. Whitworth L. H. Slatter .. A. C. Drew ... P. K. Johnson I. H. Dollittle G. P. Kragg Smith D. A. PaveYey W. J. Williams N. Waghorn ... A. F. Houlberg A. I>cwis ... J. Mcltimie ... 51 V 3« 3o •5 *4 at! •of '! OS s* 3; 43 4' 4° 3H 685
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