Supermarine Spitfire VB (oz11516)

About this Plan

Supermarine Spitfire VB. Rubber profile model (with motor tube), for indoor use.

Quote: "THIS MODEL of that immortal British fighter, the Supermarine Spitfire, was designed for flying around a pole indoors, but tests proved that is equally at home flying outdoors (on a calm day of course). So when you have built this little semi-scale job you will possess a two-purpose model. If you are not familiar with indoor round-the-pole flying, not to worry, you will find all the information you need in this feature and on the plan.

A note before starting construction. If you intend to camouflage your model (dark green and brown), colour the various parts flat, before assembly. We used the new oil-pastels (small box from any art dealer). Apply the pastel to the balsa sheet and then rub lightly with a soft rag to spread the colour evenly. Simple, no weight - and the effect is excellent.

Construction: Cut a length of 1/32 balsa sheet as shown and soak in warm water for 20 mins. Wipe off excess water and wrap around a suitable broom handle or dowel rod (7/8 in diameter approx). Hold in position with thread. Do NOT use any cement at this stage, otherwise you will not be able to slide the tube off the handle when dry! When absolutely dry remove the tube from the handle.

Cut out the formers F1, 2, 3. Open out the tube as shown, and carefully insert the formers in position, cementing well. Run cement along the tube join and close. Hold with sellotape until dry. Then cut out and add the top and bottom fuselage pieces A,B,C,D, down the centre lines of the tube. Before cementing part B in position make sure you have traced the wing rib position on both sides of part B, This will help you to line up the wing panels later on. Bore two small 1/16 dia holes for the rear rubber anchorage dowel (1/16 dia) Reinforce the holes with small squares of brown paper. Carefully chamfer former F1A and cement to F1 (this is important).

Construct the propeller nose block and prop bearing shaft as shown. You can use a 3 bladed KK plastic propeller (from your model shop) or a KK 2 bladed propeller (5 in dia), the tips being removed to give 4-1/2 in diameter. The completed propeller assembly when fitted into the front of the model (F1, F1A) MUST point DOWNWARDS as shown.

Cut tailplane and fin from n't, in. sheet. Note reinforcing strips on underside of tailplane. Assemble fin after tailplane. Cement engine cylinders and tailwheel in position.

Cut out wing panels (1/32 sht) and wing ribs (1/16 sht). Curve the wing panels to the shape of the wing ribs and hold in place with pins until cement has set. Look along wings from rip to root to see the wing panel is not twisted. If so remove the ribs quickly and start again. Note, especially that the root rib on each wing panel is sloped to make the wings slope upwards to the tip when cemented in position. This is called 'wing-dihedral'. You should use the root-jig (X) in the way shown in the sketch to get the root rib at the right angle. Take care and it's easy!

Bend the undercarriage wire (one for each wing) as shown Fit the balsa wheels (retain on axles with a small piece of close-fitting electrical tubing or blob of cement) and covers. Cement the undercarriage legs in position, reinforcing with small squares of tissue paper cemented in position. Assemble wing panels to either side of piece B using the traced wing rib position to guide you. Check for equal dihedral (tilt) on both panels. This completes your Spitfire.

Flying: Make up a loop of 1/8 strip rubber 14 in long and rub on some rubber lubricant (strip rubber and tube of lubricant from your model shop). Install the rubber motor on propeller shaft hook and rear dowel rod. Suspend model from balance point. It must hang level. You may need to add a tiny amount of plasticine to either nose or tail. Our original model (the one in the photos) did not need any extra nose or tail weight. This balancing procedure is very important, so do not skip it!

Choose a calm day, and long grass for outdoor flight tests. From a gentle shoulder-high launch your model should glide straight and land about 20 ft away. You can then wind on about 150 turns and try a power-flight.

If your model dives, bend up the rear edges of the tailplane about ala in.-fir in. If it climbs steeply, and then dives in (stalls) add a 1/32 - 1/6 piece of sheet balsa to the top of the noseblock. Turns are corrected by gently warping the rear part of the fin in the opposite direction to the turn. No other trimming should be necessary.

For indoor flying (and this is great fun in the winter, or when the weather stops outdoor flying) make up a pole as shown. Possibly you could build one in your woodwork lessons at school. The line length can be anything from about 5-8 ft according to space available. A large room, your youth hut, or best of all, the school hall (with permission of course!) are all suitable. Wind up the model, and then, attach the line hook to the loop on the wing of your model and let go! If the model will not take off bend the rear edges of the tailplane up about a 1/32 - 1/16 in. If it stalls, add about 1/16 in sheet balsa to the top between the prop block, and F1A. "

Direct submission to Outerzone.

Supplementary file notes

Article.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction