MODEL AEROPLANE NOTES

Auckland Star, Volume LXIX, Issue 142, 18 June 1938, Page 3 (Supplement)

MODEL AEROPLANE NOTES

THE SHORT-MAYO COMPOSITE. MAKING A MODEL OF THE PICK-A-BACK. TRANSATLANTIC AIRCRAFT

Sufficient space has been given to the recent trials of the Maia-Mercury combination aircraft that little need l>e said here of the actual KTcas embodied in this very revolutionary liuo. We all know that the idea is to fcVe the actual trans-oceanic flyer a chance to get started with a full load of fuel, and thus eliminate a lot of the risks of starting off with a fully (or actually in this case a grossly overladen) laden machine. We know, too, that the actual tests over the last few months have be#i quite successful and that a New Zealander was in all caseg the pilot of the Mercury. In this column we anmore interested with the making of a model, and as the diagrams are rather large for one issue I propose giving these over the next two weeks a« well as in this issue. This week we have the diagram of the upper component, the Mercury. Over the next two weeks we r hall publish the design of the Maia, or parent ship, so that at the end of the period you will have the whole lot. In the meantime we can go on with the construction of the Mercury. The model may at first sight appear a little small, but when you see the size of the Maia you will realise that we have to keep this one down a bit in order to keep the whole model within reasonable bounds as far as size is concernedTo begin construction, first of all decide on the materials to be used. No doubt you will decide on the usual material, which is balsawood, as being the best all round for the purpose. It is very light, being about half the weight of cork, is very easy to work, and finishes well when properly done. The tools necessary are few. A safety razor blade, several grades of sandpaper (or is it glaspaper?), some pins, and a rule are all that you require. The materials will be the requisite balsawood (or other wood if you wish), some balsa cement and colouring dopes. Add to these some scrap celluloid and some odd wire, and you have all that is necessary. The first thing to do is to get the wood cut to the rectangular sizes, and then, before you do anything else, paste the former designs on to a. piece of light card. Theee formers. F1 to F7. will l>e used as a check later on when you arc getting the hull carved to shape. A half former will do in each case if you cut it down vertically through the line shown, and don't forget that you require the inside shape, so leave plenty of card on the outside in order to handle these templates. Now. having the fuselage block ready, draw a centre line right round it. dividing the top and bottom longitudinally. You will see the reason for this later, as you will want those marks to line up the half-templates. Then mark along one side the position of the formers (see the bottom sketch i and then square these lines right round the block. The next thins to do U to get the side outline

Diagram of the upper component oi en the block. This is done by laying t lie plan oil the block and pricking through with a, needle at. say, intervals, closer on the curves or tracing it through by using carbon paper. Now cut the side view out. This inn bo done by hand, but if you have a machine fretsaw it will make the job reallv easy and get square edges as well. Now* you will have cut away mo*t of those original centre lines running right round the ship, so they will have to be drawn in again. It would have been a good idea to have pricked them in just a bit deeper than the waste cut so there would be no trouble in finding them again. Xow procced to shape the hull bv cutting away the obvious waste wood roughly at first and then checking at

By PROPELLER

all surfaces a coat of thin grain filler, rubbing it down "Traill and then across the grain. This will fill as much as several coats of dope. Leave to dry about an hour and then faiul over with 7.0 glassp;iper. If you want an exceptional job give it another coat of graiutiller and sand again. Then give it ii coat of silver dope an<l sand. Then another coat of silver dope and sand very lightly as the finish should now be coming up well. A final coat of colourshine should be applied after the model I is assembled »unl any little cracks or 'holes made by assembly pin#* should be filled with dalis of silver dope. Note, where wood-to-wood joints are made the d!>|>e, etc.. should lie scraped away. Cement will stick to the grainfiller, but a better job will result if you use the method nbovc. Any little irregularities or misfits can he filled up with balsa dust mixed with cement and silver dope. This is used like a woodpaste and is very useful. The good craftsman, however, will not have too inanv misfits hikl the old saving. "'A pound of putty tills a big hole." should not have to be applied in this instance. Take your time and a beautiful little job will result. With the practice gained by making this unit, the Maia will not prove so difficult afterwards.

the Short-Mayo composite aircraft. each former station with the h«ilftcmplates (both *ides. of couive. to he tln* samel. <Jet each station practically correct, just leaving about l-Kiiji oversize, and then cut away the bumps between until you yet everything smooth sum I the lines "fair"' an<l without blimps and waves. The l-Kiin oversize will disappear with this ]a*t fine sanding anil your hull i-houhl then lie very near exact. The wings are now made to shape, being sure to get a left and a right panel, as it is easy to get two lefts or two rights if you don't watch out. The flcits and ttie tail gear are similarly treated and all brought to a reasonably smooth finish. Do not attempt to assemble the model too soon as most of the finishing must be done first. (Jive

RIDDLES. | (Copied hv T. Berkhnut. 3". Princes Street, otaliuhu.) Q. Why is a big coat like a banana ' skin? A. Because it is easy to slip on. Q. Why is a cracker like a good schoolboy ? A. Because they both go off with a oood report. Q. What part of an orange reminds you of Christmas bells? A. The peel (peal). Q. When is a ship like trnow! A. When she is adrift. Q. What man dislikes a fire even though he is frozen? A. A snowman. Q. Tell me why no one has ever heard the story of the cheerful bells? A. Because it has never been told (tolled). A. What boxes stare after you? A. Pillar boxes, 'because when you pass them they look round.