MODEL AEROPLANE NOTES and General Hobbicrafts

Auckland Star, Volume LXVI, Issue 58, 9 March 1935, Page 3 (Supplement)

MODEL AEROPLANE NOTES and General Hobbicrafts

THE "STAR" GALLEON

PART 111. Now we arc ready to start building in real earnest. This week 1 .am giving you the plan view.of the hull and also the various sections, which give the true lines to your ship. A small sketch which shows exactly how to shape the hull by using templates made from No. 0 sketch will prove very useful. Now study drawing No. 4 very carefully, as this "is drawn in two half section style, the upper half showing you where the various details are placed and |he bottom half showing the actual shapes you are to cut your boards. As 1 explained before this hull is built up on the bread-and-butter system, and as all the planks are of the 6ame thickness all you have to do is to freteaw out each individual plank (or lift board., as 1 shall call it from now on), and the rough shape of the hull will automatically build up. See No. 3 (part 2). Study Nos. 4 and 5 together. The lift boards are numbered from the keel upwards. You will require about three feet of 3in by gin balsa to cut the lift boards from. This will give a bit to spare, but it is better to so do, as you will be able to go on with your work if you happen to make an error. Note that the bottom two lift boards are the only ones that go the whole length. As only half sections of the lift board gapes are given you will first of all trace the whole of the outline of the line marked 1 (sketch No. 4), and then fold the copy along the centre (dotted) line and cut the shape out. On straightening it out you will have the correct shape of your first lift board. There are several ways to transfer this to the timber. One is to lay it on the board' and prick right around it with a sharp pointed instrument, but the best way is to lightly stick tiic paper on to

by Propeller

the board and then cut the shape out with your fretsaw. Kcpeat this process with each of the lift boards in turn, being very careful to mark them with their correct numbers, and also in the case of lifts 3 and 4 as to whether they are the fore or aft parts. No. 0 lift is not actually marked as such, but as it is the shape of the top view of the upper part of the drawing you can got the shape from this. In order to be quite clear about it, it is that portion of drawing No. 4, being the aft or lefthand section and has a skylight and pinrail drawn on it. With all the lift boards cut to shape you can lightly pin them together and see the iirst rough shape of your hull come out. (.See drawing No. 3, part 2.) Now cement the hull together, lift board by lift board, starting, of course, by sticking No. 2 lift board to the top of No. 1. Smear the top of No. 1 lift board with balsa cement, place them together and rub them into a firm contact, making sure that they are fitted exactly at the right place. Place a weight on them and allow to dry for a while. In the meantime you can fit No. 3 and 4 together, both the fore.and the aft sections, and then Nos. 5 and 6. By this time the first boards will be set and the whole hull can be gradually built up, using the same process of cementing and weighting the parts.

Now your hull begins to look something like a boat, but so far it is very rough. A lot of model builders like to skip the next part, and that is the making of templates to get the correct shape. T would not advise you to finish the hull off by "eye," but adhere strictly to these instructions. It makes all the difference between a rough amateur job and the product of a real craftsman. Now have a look at sketch No. 5 and don't be frightened of it. It looks a little complicated at first, but it really isn't. The sections shown are what you would

see if you sawed the hull right through; the various points marked A B C D and E. are the shapes of the sections from the bow of the ship back and on Ihe other side of tLe sketch (No 5), I' G H J are continuations right back to the stern. You must make a half section template for each of these, and the way to do it is thus: Get a piece of fairly stiff cardboard and draw on it each section in turn, making the dotted centre line coincide with one edge of the cardboard. Now, with a sharp knife cut out' the part between the dotted line and shape oil the particular section you are making. Leave plenty of spare cardboard outside, and you will have a template just like the one shown in the hand in sketch No. 6. ' At this point you can start to carve away the protruding edges of the various lifts, but don't cut it too far. Now make particular note of this. At this stage it is necessary to draw straig'ut lines up the sides of the hull and mark them A .'to K respectively. With the exception of A and B they are lin apart. Now, with a very coarse piece of glasspaper proceed to shape up the hull to the correct section' by using the templates. I usually do ACEG Jin turn, and then go back and do tho others. You can smooth out the bumps between the actual sections given. Naturally as you work closer to a fit to each template it will be necessary to use smoother glasspaper. When the hull is this far advanced you will notice that the joints between the lift boards will act as a guide to "prove" that you have the sections correct. They should make nice, long sweeping lines without undue bumps in them. The hull is now practically shaped up and care should be taken at this stage to get a line, smooth finish. A good idea is to make up some flour and water paste and brush it over the entire hull. This will raise whiskers on the balsa wood, but will also penetrate a little and help fill the grain. Dry it out in a warm oven, not hot, and smooth off lightly with very fine glasepapcr. Repeat this several times until you are satisfied you have a perfect finish.

I think if you get this done by the end of tho week you will, or should, be satisfied and be ready to go on with me in part four.

In the meantime don't forget to put a newspaper down on the floor to collect the chips, or you will both be exceedingly unpopular with mother for spoiling the carpet.