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Model planes - mid wing aerobatic RC aircraft SC60 powered
Some details and pictures of my modified (BIG) Little Special 60 powered mid-winger model.
Looking a bit grubby with oil, she scrubs up nice though!
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The mighty SC60 uses a homemade modified silencer to keep the noise down a bit. Utilising a standard front end SC silencer joined to a turned rear section with internal baffling (tubes with cross holes), reasonably effective.
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This model plane started life as an enlarged Little Special (The Derek Woodward design). Originally Little special was scaled up to 133% original size giving a span of around 53". This allowed the use of standard 48" lengths of balsa and spruce in the wing constuction.
The enlarged Little Special flew very well powered by it's SC60 two stroke. Unfortunately however a clevis snapped on the elevator early in the model's life sending the aircraft earthwards, on contacting the ground the Earth won outright victory as usual and a major rebuild of the plane was called for.
I never use plastic links on critical parts anymore after this, and regularly check metal links as they can loose spring over time and bend open.
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Wing stripes on top only really help in telling which way is up on this highly aerobatic model.
Highly useful when rolling at over 360 degrees per second.
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Covering in Solarkote (the thick and tough polyester film).
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The aircraft had proven a good flyer in it's short life, I have always felt however that there were a few improvements that could be made to the design. Chiefly amongst these was a lengthening of the fuselarge to give a longer tail moment arm. This I feel reduces both the blanketing effect created by main wing over the tailplane and generally gives more pitch stability and elevator power.
The nose was lengthened also to accomodate a large fuel tank and give longitudinal balance without a lump of lead being needed.
So an all new fuselarge was drawn up utilising the virtually undamaged wing and tail surfaces of the original aircraft. As I was in a hurry and do not like fiddling about much I designed a basic box section fuselarge to mount the existing wing and tail surfaces.
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This plane is high performance now, but I reckon could be fitted with a 90 two stroke for really blazing speed and climbing ability.
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Aircraft takes off well from this rough un-mown sheep grazed field, despite small 3" wheels.
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When completed the finished model plane looked to my eyes well smart. The proof of the pudding is in the eating however and a trip duly made to a local field for testing.
At the field all checks were carried out and the SC60 powered up. The aircraft was pointed into wind and the throttle opened up. The aircraft accelerated quickly down the strip and was airborne within seconds.
A few climbing circuits to get the feel of the plane and then on to the basic rolls loops etc. This aircraft performs manouvers like these effortlessly, and being neutrally stable outside loops as easily as it inside loops.
This aircraft is a fast one. When flying the plane even a large flying field starts to feel small and confined with turns being required every few seconds. Being neutrally stable and naturally fast and slipery does make the landing a bit tricky. The machine is hard to slow down for an accurate landing and lacks the pitch/airspeed relationship of most aircraft. (basically this machine goes where you point it if you have enough power).
Overall then I was pleased with the rebuild and mods of the plane. The lengthened fuselarge does make an improvement to the model, making it less twitchy and smoother to fly, it also looks good flying on a low pass at I reckon is the thick end of 100 mph at full bore on it's SC60/APC prop combination.
This model aircraft is still going strong several years now since it's rebuild.
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Getting mucky with oil after a couple of flights. SC60 really pulls on the ASP prop but gets through some fuel.
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The back end of the model showing a transfer link connection to the elevator. Plenty of oil residue from the engine after a couple of flights.
This link is a replacement, the original strangely vanished!
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