Skybaby (oz8033)

About this Plan

SkyBaby. Radio control powered glider model.

Quote: "Something for single channel - a 39in span power assisted glider for .049 motors.

For a long time have been thinking that most modellers want to fly something that is reliable, simple to build. viceless and attract 'Skybaby' fulfils these requirements. Furthermore, it is a very versatile little model, capable of flying in most conditions, as windyweather is no problem with this high-thrust-low-drag configuration. Additionally, it can be flown as a slope soarer, float-plane, off snow, wet grass, on the beach - in fact all surfaces except tarmac. A little cunning could soon overcome that problem.

The version presented here is the powered flier, although Skybaby started off four years ago as a small soarer to fly off the sand dunes during a holiday at the coast. Unfortunately I have yet to find a really satisfactory way of fixing the engine mount to the wings (and still retain its elegance) so I built two wings - one with the power pylon and one without. Whilst on the point of interchangeability of role, an examination of the drawings will show a rudder that is easily removed and replaced by another giving more 'throw' (for soaring) or less, (for learning). Of course, the degree of rudder movement is determined by the position of the wire yoke attached to it. When you become familiar with Skybaby you'll probably find that you retain the soarer rudder, even for power flying and only replace it when your multi friends beg to have a go, ie if they haven't built one for themselves.

Before we start building, let me point out that we need to watch the weight. I am convinced that if any one single factor has a strong influence on performance it is wingloading - ie weight per unit wing area. Mediocre performance is not going to be improved to any marked degree by installing a larger engine, hence increasing thrust. It is the power to wing loading ratio that is significant. If it is necessary to increase wingloading, such as in high winds, add ballast under the CG. So, after that sermon, it is recommended that all up weight is kept under 21 ounces, and is preferably about 17 ounces.

CONSTRUCTION: Building should provide no problems. The structure is quite conventional except there may be more ply used than normal, but judicious use of ply is really worthwhile. Points that may need careful examination are the rudder pivots and the installation or the escapement, as these are likely to be novel. Nevertheless they are worth reproducing in your version and they may even be adopted by you as standard technique (never did like sewn hinges and glued-in escapements).

Fuselage: Cut sides from medium 3/32 balsa. Shape 1/32 ply doublers oversize and glue to fuselage sides with contact adhesive. Before the doublers (grain vertical) are pressed home, bend curvature into sides..."

Quote: "Hi Steve, Please find attached pdf plan and article for Dave Greenfield's 'Skybaby'. It is a 39in span single channel motorglider. It was originally published in Jan 75 in RCM&E, but seems not to have been listed anywhere for years."

Direct submission to Outerzone.

Supplementary file notes

Article pages, text and pics.

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