RC Powered Paraglder from Martin Piñeyro on Vimeo.

I built this radio controlled powered paraglider for using it as a platform for aerial photography. The characteristics of this type of aircraft (mainly portability, flight speed and autonomy) make it highly suitable for this task. I started this project by working with the plans of a power kite (Eliminator II). The aim was to modify the aerodynamic profile of the kite so it can stay inflated even with an angle of attack close to 0° (situation for which the kite was not designed) and build a prototype to test viability of the project. One of the first problems was to find the appropriate material to build the paraglider as in Uruguay there are no Rip-Stop Nylon providers (material used in real paragliders). The material must (at least) be lightweight, durable and have low porosity (in order to keep the air inside the wing and force it to adopt the aerodynamic shape). As for the thread used to sew the panels that form the wing, a 100% synthetic yarn with low elasticity must be used. I found a fabric that appeared to be adequate and sewed the first wing. While building this wing was a fundamental exercise, it never flew because it came out much heavier than expected. Shortly after I managed to get the right material (Rip-Stop) and got the plans of a parafoil that had been tested in powered paraglider RC models. This paraglider was much easier to cut and sew than the first one because it was designed to be constructed using less panels.

Once this second wing was finished, I began building the trike in which the engine and servos are mounted. The trike is made of steel rods (piano wire) welded using copper and tin. It also has wooden sections that serve to mount the engine, fuel tank and the two servos (one for steering and the other one for the throttle). The receiver and batteries of the radio control system are mounted directly on the steel frame.

Steering and elevation:
Unlike the real paragliders, this model uses only weight shifting to control the direction (no modification of the aerodynamic surface takes place for steering purposes). A brass bar connected to the steering servo allows shifting the trike’s weight from one side to the other and consequently change the trajectory of the model.

Elevation control is achieved through the engine throttle (a servo controls the air inlet of the carburetor). When the thrust of the motor increases, the speed of air passing over (and below) the surface of the paraglider increases producing a greater lift and consequently gaining altitude. If instead the thrust decreases the model loses height. The engine can also compensate for the model’s relative speed to the wind, which essential in order to maintain altitude when flying downwind.

Aerial Photography:
Endurance is the main advantage of using an internal combustion engine (0.25 sq in <> 4 cc); with a single tank of fuel is possible to fly for 40 minutes. The drawback is that it causes very strong vibrations making it practically impossible to take good pictures in flight. To make a good platform for aerial photography out of this model it is necessary to work in an enclosure or housing for the camera able to absorb vibrations without adding too much weight, so that will be the next step.

RC Powered Paraglider