FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1915
1915 - 0033.PDF
JANUARY 8, 1915. Edited by V. E Models Driven by Compressed Air. (Continued from page 17.) Wanted, a Compressed Air Motor.—What is wanted is a simple but good and reliable (i.e., non-leaky) motor at a reasonable price. The construction of the rest of the machine presents no difficulty, nor does it require any special or expensive tools. This, however, is not the case with respect to the motor, which requires a good and accurate lathe and skill as well. There is, or will be shortly, without a doubt, a demand for such a motor, and it must not be forgotten that a model aeroplane is not the only type of model on which such a motor can be used success fully. The writer knows personally of a very successful submarine model on which such a motor is employed, and also of several of model fast warships where such is being used. Its great advantage—from the ordinary amateur's point of view— is its simplicity for any type of model. If we use electricity, unless we are in a position to recharge our own accumulators, this business is a constant expense and nuisance. When using steam, all sorts of worries and troubles arise, either the lamp blows out or the pump valves refuse to work, or some other trouble arises ; if we use petrol then we must be prepared to go in for very large models, and unless we are an expert, have all sorts of difficulties with the ignition, the mixture, the sparking plugs, to say nothing of, perhaps, finding a moment of inertia in the carburettor. For rock bottom simplicity you cannot beat the c.a. type of plant; even rubber has to take a back seat in this respect. Best Type of Motor. The best type of motor has yet to be found ; with respect to the c.a. driven model warships mentioned in the preceding paragraph, an ordinary high-pressure steam engine is being employed ; here, of course, a little extra weight does not matter, but such, unfes lightened very considerably, are quite unsuitable for model aero planes. So far as one can tell at present, two single-acting cylinders, with a D slide valve acting across the bottom of the pistons, and a piston fitted with a cup-shaped oil-soaked leather washer (as in Mr. Hayden's model), has given the best results ; but Mr. Hayden is constructing a new motor, twin single acting opposed cylinders fitted with a rotary valve, and the results will be awaited with con siderable interest. There are two types of c.a. motors which we cannot personally from our own knowledge of them recommend ; one is the rotary type, and the other that in which the exhaust takes place through holes in the walls of the cylinder. ( To be continued.) Trial by Fire; or. Revenge is Sweet, We have in our time seen more than one model aeroplane broken up into pieces and hurled to "perdition" when broken beyond repair, or when failing to fulfil in any way the hopes of their designer. Personally the writer must confess to having " executed a war- dance " on one model. It was in the early days of experimenting Mr. F. R. Kitchens' model burning, photographed at 20 seconds' interval. \mm JOHNSON, M.A. with geared motors, when the only suitable or unsuitable cogwheels that could be obtained were got from cheap clocks. The cogs ripped and severely cut the writer on the inside of his hand, naturally the model was dropped at his feet, and so great was the pain that relief was sought in a game of football with the model, what was left— well, was left, there wasn't much left to take home. So far, how ever, as we know, the experiment of our correspondent is unique, a record case, we should think, of cold-blooded, no, of hot fiery destruction. His communication is as follows: " I enclose two photographs which I think may be of interest to readers ot Kl.lc.HT. The machine it represents is one of my failures which broke beyond repair whilst being tested. Having removed all pans of value, [careful man], I soaked the machine in paraffin and set light to it. The photographs illustrate two stages in its combustion, the second being taken 50 sees, after the first. The exposures were 30 and 40 sees, respectively at F. S taken at 7 p.m. (August)." An American Twin-Screw Model. The model shown in our illustration was built by Mr. Frank Patky, of the Illinois Model Club, Cicero, U.S.A The chief dimensions and puticulars are as follows :—Length, 36 ins. The frame is made of VV to i in. spruce. The span of the main plane is 27 ins., the chord 475 ins. The front and back spars are made of J and ,:V, in. pine; there are eight ribs, ,>, to fo in., also of pine. The camber cross rib is j, to 1'',, in. pine The chassis is built of Mr. F. Patky's twin propilUr Amjrican duration model. No. 20 s:eel piano wire, and the axle of No, 22. The wheels are 2 ins. in diameter, and are made of T',. in. pine, and one in. square piece of \ in. wood serves as a hub. The hub is glued in, ana the whole wheel is wrapped around with thread, which is then covered with silk and doped with varnish, thus making a very strong and
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
