I was going to college when the first Rogallo prototype was designed and wanted a small compact aircraft that I could fly in tight spots. I got the idea from a small picture in a model airplane magazine that had no real explanation. I used the image as inspiration and then began experimenting until I had a flying Rogallo. I actually made a CAD model of the airplane and laser cut the parts out of balsa wood, but it wouldn’t be hard to cut them by hand. All the parts are shown here except the cross piece that attaches to the wing. This piece requires a different shape depending on the shape of the carbon rods used in the wing. I upgraded the mast attachment point to lite ply to take larger flight loads. All the wood parts are shown in the drawing below. The frame is glued with CA to look as it does in the finished pictures.
The wing is super simple and made of just four carbon rods and some plastic. I originally used a trash bag but upgraded to a grocery store produce bag. The produce bag is lighter and looks better. I used 1 mm carbon fiber rods for the frame. I lashed all the joints with fishing line and then added superglue for a solid connection. The plastic is taped onto the frame with medical tape on my wing because it is strong, flexible, and clear.
I stole all the electronics from a Horizon Micro 4 Site. The micro 4 Site uses a Spektrum “brick” receiver with integrated servos and brushed ESC. I moved the board around to get the CG in the right place. The CG must be at the connection point of the wing and the fuselage at the light ply pieces. The small linear servos were attached with homemade control rods consisting of a small carbon rod with staples attached with heat shrink tubing.
The wing is made with 4 carbon fiber rods and a plastic produce bag. I cut the produce bag into a perfect square. The carbon rods are glued with an angle of about 60 degrees between the front two rods. The wing should then be carefully taped onto the carbon. The mast provides about 5 degrees of incidence on the wing relative to the fuselage. This is important for decent flying characteristics.
The first time I tried to fly the plane, there was an awful throttle to pitch coupling. I determined this was caused by a thrust line that was dramatically below the CG of the plane. To correct for this, I bend the plate holding the motor down by about 6 degrees. This moves the thrust line closer to the CG.
The plane flies absolutely beautifully. It is very light and nimble. The design has an extremely low wing loading which allows for real sharp turns and super slow flight. The Rogallo performs well at very high angles of attack, up to 60 degrees. I have flown this airplane inside college study rooms and lecture halls. This is not a racer and the wing will deflate at high speed causing sudden drops. It also cannot fly upside down.
