The object of this series of articles is to take you through the steps required for the construction of model aircraft from plans.

In this section we finally get to build something – A construction board! One of the most important items you will need as a Modeller who builds from plans is a construction board. I can show you how to make one, but decisions regarding size, and materials are up to you, so if you don't want to build one as big as the example, or you want to use different materials, that's fine. It is usual to build your board as large as you can. This is because you need to build items like the fuselage (or body) of your plane, and the wings, in place actually on the board. So if for example you have a plane with a five foot long one piece wing, you would struggle to build it on a four foot wide board. Also it is usual to mount your whole plan sheet onto the board, and a large board will allow you to do this. So how large is large? The board I am making as an example is six feet long by three feet wide. The Chorus Gull plan sheet is 5ft 6in x 2ft 6in so this will allow me to mount the whole sheet onto the board, and leave some important working space around the edges. A six foot by three foot board will allow you to build from the majority of plans because plan designers would usually continue onto further sheets if their plan exceeded this size. I know that many of you will be building smaller models, and so will require a smaller board, but if you enjoy building from plans you may well graduate to larger models, which are more challenging, and save you the most money, so it may be a good idea to start with a large board in the first place. As I said above the size decision is yours, only you know how much storage room you have available, both for the board and the models you will be building on it.

For smoothness, cost and availability, MDF is hard to beat. MDF stands for Medium Density Fibreboard, and it can be purchased at any decent D.I.Y. shop. A standard sheet is four feet by eight feet, and it comes in a variety of thicknesses. The board used in the example is ¾ Inch thick, and cost me £5-99. Below is the cutting diagram for a 6ft x 3ft construction board Starting with a standard 8ft x 4ft x ¾ Inch Sheet, you should end up with, One piece 6ft x 3ft which will be the top of your board. Two pieces 6ft x 3 Inches which will be the long strengtheners. Five pieces 2ft 10 ½ Inches x 3 Inches which will be the short strengtheners. Three pieces which will be spare.  Ask the shop to cut the board for you as they have the machinery to do a much better job than you can at home. Some shops will charge you for cutting – pay them, it's worth it. Every cut will be the right width, the right length, and completely square - if it isn't ask them do it again. I was charged £3-50 for the cutting, so the whole sheet plus cutting came to less than a tenner, and getting a cut sheet into a car is far easier than trying to fit a full eight by four sheet in. Remember... You must make absolutely sure that the sheet you buy is totally free of any warping, twisting, sagging, or similar defect. Only by starting with a perfect sheet will you be able to build a perfect construction board. This is vitally important because any defects in your construction board will inevitably be transferred to your model, and must be avoided at all costs.

When you get home you will have something that looks like this. (Can you spot the deliberate ??? mistake). Putting things together is quite simple. We will use the “screw and glue” method which will make your board very rigid, and will also help you to keep things absolutely “square”.

Step 1 The screw and glue method is almost self explanatory, the joints you are going to make are first glued, and then screwed together. The pressure from the screws, along with the glue makes a very stable, strong, joint. The first thing you need to do is lay your top piece good side down in such a way that you can drill holes in it without drilling into the carpet. Then, using a pen, or pencil, place one of the longer strengtheners in position, flush with the edge of your board, and draw a line along it. Do the same for the other long side.

Next place two of the short edge strengtheners in place flush with the edge, and draw a line along them. You should now have a line all the way round your board, something like this…

The final three short strengtheners are placed at 18 Inches, 36 Inches, and 54 Inches from one of the short sides. (These are ¼ of the way across, ½ way across, and ¾ of the way across). Draw a line on both sides of these three strengtheners.

The screws used in the example are 3.5 mm x 50mm, so using a 3.5mm drill bit, drill all the holes you will need to attach your strengtheners. Set your holes five or six Inches apart and make sure they are centred between your lines. Having drilled the holes, turn your top piece the right way up, and run a countersink tool into the holes. This will clean the holes up, and allow the screw heads to sit into the top board without protruding. If you do not have a countersinker you will usually find that the screws will go in level with the surface if tightened sufficiently.

Step 2 Having drilled, and countersunk the holes, your next step is to attach the two long strengtheners onto the two longest sides of the board. Dribble a small amount of wood glue along the whole joint, and place the glued strengthener in position. It is important that you butt the strengtheners right up to the outer edge of your board because the short strengtheners are designed to fit between the two long strengtheners. So make sure that they fit BEFORE screwing anything into position.

Step 3 Carefully tighten the screws, starting at one end and proceeding one at a time to the other end, making sure that your strengthener is still butted up to the edge before tightening every screw. Then wipe away any excess glue that has squirted out of the joint.

Step 4 Fit two of the short strengtheners to the two short outside edges of the board. Then fit one short strengthener across the exact centre of the board, and the remaining two strengtheners at the quarter and three-quarter length positions, using exactly the same techniques described above. When you have finished the bottom of your board should look like this. Lay your finished board somewhere flat until dry. Be aware…M.D.F. and water do not mix. To protect against accidental spillage I gave my board a coat of cheap waterproofer, and left it to dry overnight. If you do not wish to do this keep all liquids well away from your board. You should end up with a good solid board that will last for years.

Remember The example board is HEAVY, so don't move it alone unless you are capable of doing so. Usually you would place your board on a bench, or table top, while building your model. It is wise to ask someone to help you to lift your board onto the table, and to make sure that your table is strong enough to take the weight. For the reasons described above it is my choice to build my board this size. You do not have to build a board as large as this, you can build any size board that suits you, provided you can fit your model onto it.

The list of tools that an aeromodeller MIGHT use is endless, ranging from a craft knife to lathes and milling machines. Most of us however will only need a few simple readily available items, a short list would be; 1… A Craft Knife, and spare blades. Not a “ Stanley ” type knife because the cutting angle is too great to make a square cut in thicker sheet. Craft knives of the scalpel type have blades with a much shallower angle allowing you to cut more squarely. 2… A Metal Ruler. This has to be metal because you may need on occasion to run your knife blade securely along its edge. 3… A Metal Try Square . Important for making cuts, and gluing items, at exactly 90 Degrees. 4… Pliers. For bending and holding. 5… Sandpaper. Of various grades but especially fine grades. 6… Pins. Try to find strong pins as M.D.F. can be a little hard to stick pins into. 7… A Small paint brush. For various uses. This list should cover most of the tools that you will need, however, there will always be other useful items, Drill Bits, Scissors, some Screwdrivers, etc. etc. Read the Articles that are to follow about building the Chorus Gull, and whenever we use a new tool that we haven't needed before I will make special mention of it.

When you have chosen and built your construction board, and obtained these few tools , you are ready to proceed to the next section – Building a Wing.

 

Article by Rick Harding for Bumpy Green Model Aerodrome

Comment by Grot on 20040120092024. Rating 5

It will help a lot if you surface your board with a sheet of Sundela. This is fairly expensive (about £35 per 8x4 sheet)but will last for years and allows you to push in pins with your fingers but holds them very tightly. This is available from any good timber stockist eg Jewsons.

Comment by Tim on 20040210161059. Rating 4

Presumeably the table upon which the board will sit will have to be bigger than the board? Otherwise, won't the strenghtening sections somehow overlap the table or otherwise become a hindrance? Perhaps the baord could be screwed to the table?

Comment by Grot on 20040229224849. Rating 5

I use the heavy duty plastic trestles from B+Q about £14.00 each but very sturdy to sit my board on. These allow the whole lot to be stored flat when necessary.

Comment by Grot on 20040328123552. Rating 5

I just use those nylon tressles that you get from B+Q £20 the pair.

Comment by Grot on 20040328123703. Rating 5

By the way two enries are because of price change

Comment by Paul on 20050320224315. Rating 4

I have been using those soft ceilings tiles you find in offices. They accept pins very easily, but must be stored flat as they warp easily- perhaps attatching it to a board as shown here would be a possible approach? If you used double sdided tape (eg carpet tape) you could easily replace the tiles if they got damaged.

Comment by Bob on 20050906173556. Rating 3

I use 12mm plasterboard, which accepts pins easily and is a cheap, but efficient alternative.

Comment by Bob on 20050906173645. Rating 3

I use 12mm plasterboard, which accepts pins easily and is a cheap, but efficient alternative. Any chance of seeing some plan tips yet?

Comment by Bob on 20050906173821. Rating 3

I use 12mm plasterboard, which accepts pins easily and is a cheap, but efficient alternative. Any chance of seeing some plan tips yet?

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