ACES UK

FOAM WINGS
You make up a wing ROOT template, and a wing TIP template. Pin these to the cut-out foam (don't forget the Washout, nominally about 4 degrees min.) blank and voila! Loadsa-wings. These are then covered with brown paper and flexkoted, or covered with 1/16th balsa or suitable Obeche. Add LE, TE and ailerons as required.

Join the wing halves together.

A set of all foam Spit wings, with no wood (LE,TE etc) at all. They were wire cut, but due to the elliptical nature, need to be hand sanded to the correct finish. Not for the faint-hearted. Foam tips added. Ailerons cut from shaped wing AFTER covering, which was brown paper and flexikote. Aileron torque tubes/arm assemblies are just let into the top surface of each wing and held in place with a few dabs of Epoxy. Use lightweight filler to finish prior to flexikoting over filler. It doesn't get much simpler than this!!

FOAM FUSELAGE
The Fuselage is made in sections. Like the wing, templates are made to pin to the foam blocks for each section, and the Hot Wire cutter will trace out the rough shape. Each block can be hollowed out where necessary. After gluing all the blocks together, you sand for a nice curved shape. The engine mounting bulkhead, wing seat and cowl are added. Cover the whole thing with brown paper for strength.

Spitfire nearly finished. All-foam Fuse, which will be covered in brown paper and Flexkote. 1/16th Balsa skinned foam wings. It's difficult to cut Spit wings from foam - they're elliptical. These were sanded by hand from elliptical blanks. They'll be tissued and doped, then painted. This method for the wing is VERY strong, but not the lightest.

If you're really keen, you can mass-produce your own airforce. Here's Esa Niskanen from Finland with his squadron's seasonal requirements (Curtis Hawk 75). Just make sure that it flies before you try this at home!

The easiest way to build the wings is:-

* Cut-out shape of bottom wing skin (without LE or TE) in 1/16th balsa.
* Glue on ribs.
* Glue on top skin ( include washout).
* Fit TE, Torque Arms and Ailerons. (For Spitfire etc, ailerons are cut from wing).
* Fit LE.
* Fit 1/2" softblock tips.
* Join wings. We never bother with a bandage.
* Cut hole in wing centre for servo.

Fuselage can invariably be made from two slab sides of medium 1/8th balsa. The bulkheads, engine mounting bulkhead, wing seat etc are fitted. To shape the nose, we use soft 1/2" balsa in front of the wing. The rear of the fuselage can be planked with 1/16th or 3/32nd balsa.
Tailplanes are usually made from light 3/16th balsa.
For top decking, slap on a couple of lumps of white foam, and sand to shape. There is no strength required here.

The wings can be held on either with rubber bands and dowels through the fuz, or a peg in the Fuz at the LE and a screw through the wing into the Fuz at the rear. The band method is certainly simpler to build and more forgiving on those bumpy landings.

Canopies can be quickly sanded from a block of foam. If you intend to make a few of the same model, then its worth making a wooden plug of the canopy, and vac-forming a Coke bottle. This makes a good, scale-like clear canopy.

COVERING & FINISHING

As a quick alternative to the above, you could directly cover all bare surfaces with a fuel proof paint, ie without dope or Flexkote.

Something different. Here's one of Andy Sheen's partly finished Hurris, but with brown 2" vinyl tape covering. Lay it on nice and tight, and finish of any wrinkles with a COOL iron, pricking out airbubbles as you go with a pin. Gently rub with wire wool, then paint as normal. Note that this wing has no wooden parts.

RADIO

FUSELAGE CONSTRUCTION After making cutouts for the ply parts in the foam blocks forward and rear ward of the wing position, all the fuselage foam blocks are glued together. The ply Engine mounting bulkhead is glued in place. Whole fuz is now sanded.
Fuselage and wings are now brown papered, after ensuring that wing sits flat and level in fuselage opening. The tailplane seat is cut from the rear of the fuselage, Some a/c will use this offcut for fillets later. Ensure that Tailplane is level with the main wing, and are at the correct incidence (0 deg). The wings are ready to have the ailerons cut out.
TAILPLANE Usually made from 1/8 or 3/16 balsa, finished with a light coat of Dope. Use Tri-squares to ensure right angles when assembling.
FUSELAGE with brown paper, and Tailplane assy fixed in place.
Fuselage recess for silencer. This varies depending on engine. Mount the engine/mount first, and see what material needs to be removed (if any) to allow the silencer to be fitted. Add a a layer of Brown Paper around the cut out area. The Rear Wing Mount assembly is fixed in.
Cowl mounts, made from double thickness of 1/8 liteply. Cut to shape, and glued on at 4-5 suitable places to retain cowl. Use small self tappers for cowl retention.
Snake outer is trimmed flush with fuselage. A small fillet of light filler is applied where the rear of the fuselage and the rudder meet.
Cowl cut to shape. Again, this is done with the engine in situ (without silencer & needle) Cut a little at a time, until all the necessary material is removed. You can then determine where to make the hole for the needle, and slot for the silencer.

Torque Tube slots filled, and ready for a local application of Brown Paper.

Brown Paper over Torque Tube slots.

Engine installation
Elevator operation.
Radio installation. The position of this is usually determined by the CofG. Fit evrything to the a/c except cells, rec, and throttle/elev servos. While balancing the a/c, move these items around on top of the fuselage to determine the best position.

These types of cowling are more preferrable than built up wood. They are stronger, easy to make (once you have the plug!), and are pretty good for scale appearance. Oh, and cheap too.

VACUUM-FORMED and/or DRINKS BOTTLE TYPE COWLINGS.
1. Carefully trim off any "curling-in" on the back edge of the cowl with a pair of scissors - keep the cut straight. This "curl" is caused by the way that the polycarbonate rolls itself around the back of the mold when shrinking, and cannot always be completly removed when the cowl is cut away from the mold. This cutting should effectively shorten the cowl by no more than 1-2mm.
2. Fit the ENGINE MOUNT. Use thrust if you want to, but this is not normally required. Ensure crankshaft exits the cowl centrally, otherwise the spinner will be off-centre.
3. Offer the engine to the engine mount, and note the longitudinal position in which it will finally be fixed.
4. Measure the distance from the Front of the Fuselage Bulkhead to the front of the Prop-Driver (ie, rear of prop)
5, Whatever this distance is (eg 90mm), the Front Face of our cowling needs to be approximately 3-4mm less than this, ie 86-87mm.
6. Offer the cowl to the fuselage. If the fuselage is foam, and needs to be covered with paper, the cowl should slide over the fuselage for at least 12-15mm, when it is in the correct longitudinal position. If it is to tight, sand the fuselage more. If it is too loose, you can build the fuselage thickness up with extra layers of paper at the nose. Also note, that if the cowl is loose, eventually it will be cut longitudinaly to ally positioning over the silencer. Any looseness can be taken up by pulling the cut cowl tight around the fuselage, when making the cowl fixing screw holes. Furthermore, some cowlings are made for modified fuselage/engine partnerships, and may be required to be reduced in length.
7. Once the accurate final positioning of the Engine/Mount/Cowl has been established, the engine mount can be drilled and the engine temporarily mounted (Without Needle valve or silencer). Ensure that the engine is straight etc.Block up the exhaust port, fuel inlet, needle valve and carb intake with tape.
8. The COWL MOUNTING BLOCKS can be glued to the Bulhead. Normally there are four positions - Top, Left, Right and Bottom, slightly offset to be closer to where the slit will be cut for the silencer. For some large cowls, it is easier to fit an extra fifth mount. Ensure that the Mounting Blocks are sanded to follow any taper of the fuselage propfile.
9. Now slide the cowling over the engine. Some cowling material will need to be removed to allow for cylinder head, carbeurretter intake etc. Mark the approximate positions of waste material. Go slowly, and use a sharp pointed knife. Do not try to cut all the waste away in one go - take many small cuts. Eventually, for a perfect fit, the cowl should sit over the fuselage by at least 5mm, with the front face of the cowl about 3-4mm behind the crankshaft prop driver.
10. Temporarily fit the spinner, and hold/tape the cowl in place. Check up/down/left/right alignment.
Drill a small 1.5mm (Tapping size) hole thru the cowl plastic into each of the four or five cowl mounts.
11. Remove the Spinner and Cowl. Open out the fixing holes in the cowling with small needle file, to allow the small self-tapping screws through.
12 Fit cowl using small self-tapping screws. Check for straightness with the fuselage, and alignment with the spinner fit. If incorrect, it may be possible to reduce the error by elongating one or two cowling holes.
13. Looking through the transparent cowl, mark out any hole positions required for Needle valve(s), Fuel tube exits etc. Also, ensure that there are adequate cooling vents and airflow for the engine.
14. Before painting, clean all old glue/markings away with cellulose thinners (NOTE some plastics may not like Toluene). Lightly sand with fine sandpaper etc. until the surface goes dull.

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