Bell P-63 Kingcobra (oz14197)

About this Plan

Bell P-63 Kingcobra. Radio control sport-scale model for electrci power. Wingspan 1216 mm.

Direct submission to Outerzone.

Quote: "Hi Mary, Has been some time since I last sent some plans to Outerzone. Now I have this one that will be the first of five similar models. As explained in the accompanying article, in Italian, I was bitten by passion for unlimited Reno racers. Having seen a model in an American modeling magazine specified in my article. Plan is in dwg file as usual. Ciao,"

Note the 'original' drawing here is the CAD zip download (in dwg format). That's the file that Giuseppe sent us, and that is his design, his work. The PDF file you see here is really just a taster, a PDF file in this slot for Oz users who don't have a CAD viewer.

Update 17/11/2022: Added article, thanks to Giuseppe.

Quote (google-translated from the Italian): "It is difficult to say what drives you to build one model instead of another, easier to say why you stop, with few things to do to complete it, the construction of a model that has kept you busy for months and months: the need for a respite.

Whatever your answer, it happened to me, in early last December, to suspend the construction of the Little Dipper, model for a 110 cc gasoline engine, to move on to redesign and build a much smaller model with electric propulsion, of which I had downloaded from the network and put aside while waiting for the right moment the pdf file of the construction article published at the beginning of 2017 on Model Aviation, the American magazine of the sector.

This is the semi-reproduction, very semi and little reproduction, of the KingCobra, an aircraft born as a fighter during the Second World War, but converted into a ground attack aircraft given the poor flight performance that put it in great difficulty against the agile Japanese fighters and the fast German fighters.

Almost all the survivors of the war then made an inglorious end like wreckage, some escaped to end up in some museum and others were lucky enough to continue to fly, more or less modified, as racing planes until the early 1970s.

Perhaps it was the idea of the racer that attracted me, together with the fact that the model is presented as possible to hand-launch, furthermore its dimensions and characteristics have convinced me that the Chinese economic scooter (but why emphasize its origin, so much now everything is Chinese, whether low cost or normal cost) that I had installed on a recently built biplane was standing idle due to the poor flight characteristics of the model.

Another reason, as perhaps you will be able to see from the photos if the publisher chooses the right ones, I still have a lot of balsa coming from surplus for Aviomodel boxes saved years ago from the flames for which they were intended which, despite being of modest size, they are easily used in the construction of small models.

As indicated in the drawing, the required electric motor must have a power of around 600-700 W and about 1000-1100 Kv. This last abbreviation is commonly used to indicate the rpm of the engine, don't ask me where it comes from, I have never been able to understand its origin.

At the moment the motor in use is a 1100 Kv FullPower 3548A, powered by 3 4200 mAh cells that runs an APC 11x5.5 in a more than satisfactory way. It is possible to hand launch while stationary simply by holding the model from above and letting it go, with a slight push, with the nose tilted upwards by 30-45 degrees. The power available is perfect and the model is able to climb vertically indefinitely and is fast, but ... but I was hoping for a few more km / h.

I will try a 10x7 and, if I am still not satisfied, since I find myself mounted on a bound flight acre a 700 Kv and 4 cell Hacker 30-10XL that always promises 700 W, I will see if it will be the case to trade.

The weight of the model with 4200 mAh battery is 1800 g, the flight is crisp, easy and fun and not at all critical, to make sure of its characteristics I tried the spin and, slowing down to the maximum and pulling all the cabra, it requires rudder control to go there, when released it comes out immediately, so no fear of sudden wing stall at low speeds, landing is easy and efficiency is high.

The model is also designed for launching with a catapult, simply insert a firmly glued hardwood block in the fuselage in front of the wing into which to screw an L-hook.

The construction is not the simplest, but nothing special, it is necessary to have some experience and desire to make shavings and balsa powder - all stuff that, for old model makers like me, replaces any aphrodisiac.

The wing is built in two joined parts without any spar with a head bonding of the central ribs. Resistance to bending is guaranteed by a 3-layer sloping glass fabric bandage of 100 gr / m2. The first layer is a central strip about 5 cm wide, on this a strip 8-9 cm wide is placed to finish with a last strip at least 12 cm wide. The wing is finally covered entirely with 40 g / m2 fabric and epoxy resin for lamination.

The tailplane can be made, as indicated on the original drawing, from shaped 10 mm boards or even from 5-6 mm boards with rounded edges only. I preferred to have them arched, mostly for aesthetic reasons.

The fuselage having a completely ovoid shape, is built by dividing it horizontally into two halves.

The presence of the battery holder plate and the 5x5 balsa battens allows easy longitudinal alignment by blocking the aforementioned components on the work surface. Once the frames are glued in position, the sides are positioned, in turn divided into two parts, and the lower part is completed by covering with 3-layer balsa strips. and of the sides as well as to complete the cladding without particular warping problems. The removable canopy, necessary to make the insertion and extraction of the batteries practical and quick, is made in a single piece with the fuselage to allow the strips of the covering to take the right curve, it is separated from the body by cutting the covering with a hacksaw..."

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