Modelling a twin-engined aircraft, OV10A Bronco

Now I have 2 sets of identical motor and esc, how about a quick to build twin motored model?

It has to identifiable as a scale model and one that is easily identifiable by the public. I don't want it to fly in circles and eights, I would prefer it to be more spirited, able to perform mild aerobatics, such as the basic loop, roll and stall-turn. It has to be small and light because the motor is only about 10gm a piece and therefore has to be structurally simple, easy and fast to construct.

A P-38 would be recognisable by majority and OV10A lesser. However, P-38 has dihedral, while it is good for flying especially with the twin rudders, it is more difficult to construct because each boom has to have the wing seat in a handed manner. Also, a P-38 would be rather sizeable if I adopt the scale according to the size of the propeller. An OV10A has no dihedral, meaning the majority of the boom construction is identical, and it has largish propellor. 5" propellor is the largest my motors can handle, 4.5" would be better as tried out in the modified Bug-e fun, the model span of the OV10A would be perhaps around 25". Also, the OV10A has simple slab sided pod and boom (the awkward thing to construct would be the long and bulging canopy), unlike the P-38 which is oval in cross-section, has large rectangular wing and stabiliser, very long nose which is good for CG balancing.

I did a plastic OV10A model when I was a teenager, I chose it then because of its simple lines, perhaps I could do up a RC model now.

OV10A

• Wingspan: approx. 25" (proportioned by 5" propellers)
• 2 x Turnigy 2900kV motor (housed in the booms) and Turnigy 6amps ESC (housed in the pod), running 5x3" propellors, rotating outwards
• 2S 1000mah battery or two 2S 500mah batteries (housed in the pod for CG balancing), requiring to be fabricated, two sets of motor-wire extensions and an appropriate Y connector if both ESCs powered with a 2S 1000mah battery
• One central 9gm servo in the pod for the two ailerons
• One 9gm servo for the elevator in one of the boom, curved upwards to the elevator, substitute the control horn with an ez-connector.
• One Hitec micro receiver in the pod
• Wing constructed of 1/16" curved balsa sheet with exposed stiffeners at the bottom and a continuous thin carbon fibre strip glued under the leading edge for increased durability. Ailerons are hinged and activated ate via long aileron arms all the way to the central pod.
• Alternative wing would be more built up, it would be sheeted fully at the top and at the bottom from boom to boom at least.
• No flap-control. It seems a great feature and should be simple to construct, but let's keep it off.
• Stabilisers constructed of 3/32" or 1/8" flat sheet
• Pod constructed of 2 pieces of 1" thick blue foam, maybe I will make it knock-offable.
• Alternate pod would be balsa sides and bottom, blue foam pod nose and tail pieces.
• Canopy is a carved and sanded blue foam piece, attached to the pod magnetically for easy access to the battery/batteries, ESCs and receiver.
• A more attractive alternative canopy/cockpit, but which involves more work, is to form a clear canopy. Simple push moulding is out because of the bulging shape of the canopy, a more practical approach would be to carve a male mould from blue foam, and shrink a clear bottle over it. With the pod constructed, balsa sheet will be used for the two bulkheads and canopy/cockpit floor. This underlying frame is then fitted out with dashboards, headrest etc and painted and the two pilot figurines installed. Then the shrunken plastic piece is glued to the underlying frame and the excess plastic trimmed. The canopy is then taped for the canopy frame and the whole assembly magnetically mounted onto the pod. The canopy is a prominent feature of the OV10A, a solid blue foam piece while dimensionally accurate would not be able to create much interest.
• Booms constructed of 1/16" balsa sheet, with bottom access (hinged and taped) to swap motor wires.
• No rudder-control. I would like to have control over the twin rudders, but to maintain simplicity and keep the weight down, I may have to forego this. If there is going to be rudder-control, I would use 2 x 5gm servos housed in the booms and connected through a Y to the receiver at the pod.
• The pod and booms could have 3mm aluminium tubes glued in to receive the removable undercarriage, made from 1.5mm piano wire, friction fitted into the tubes.
• Hinged with Guardian's surgical tape or narrow pieces of filament tape, covered with tracing paper (bottom of wing shall be bare), white glue coated, sprayed basic colours, unless I can find suitable coloured film to iron on, which is the preferred choice for lightness.