RC Aircraft

The Freewing Canard is a novel fixed wing configuration concept that can fly with a wide range of CG positions. This is enabled by a freely pivoting front wing, which can be trimmed to provide variable lift, but imparts no moment on the rest of the aircraft. This means the point at which change in the moment over change in AoA is zero is at the quarter chord of the rear wing. For the aircraft to be statically stable, the CG can be placed anywhere in front of this neutral point, effectively giving the aircraft a ridiculously large static margin. After building a series of small prototypes, and testing dynamic stability in AVL, the concept was applied to a large 10 ft wingspan UAV designed for fertilizer application. This was the central technology behind a project I lead at a student run engineering club at my University, and a startup I pitched at at my school’s Environmental Innovation Challenge. 

This plane went through three iterations. The first model hit a tree and disintegrated. The second version is pictured above. It buried itself in the ground after its wings folded at 90mph. The main challenge in both cases was a lack of rigidity in the foamboard. The control surfaces tended to flutter violently above 70mph. The final reinforced model and its telemetry data are below. 100mph was achieved more or less in level flight. Each peak in the graph represents a full throttle run, with each sequential run in opposite cardinal directions to rule out wind.

Designed to challenge my intuition of conventional rear-stabilizer aircraft. The key to making a canard work is to ensure the lift on the canard grows at a slower rate than the main wing for a given AoA. More precisely, the canard should have small enough effect on the change in moment over change in angle of attack that the neutral point should be near the rear of the aircraft. For a given static margin the CG must be in front of this point, and obviously you want your main wing to take most of the loading, so getting this neutral point as far back as possible, while still having good control authority is the challenge. Good stall recovery requires the canard to stall first, hence the swept leading edge.

Designed/built for fun.

Built for a high school science fair using electronics from an old rc plane. The receiver/servos are battery powered, and the throttle channel toggles an on/off switch between the solar panels and motor. Could fly self-sustained around noon on a cloudless summer day. Any wind, clouds, or less than direct sun and it couldn’t stay aloft.

Designed/built for fun.

Ideated as a means for advertising revenue for my RC plane club during school assemblies. Built out of Mylar balloon stock (very hard to find online for cheap), with seams sealed using a clothes iron. The final shape was determined using Johannes Eissing’s excel program for blimp gores. Unfortunately the project never made it to fruition due to covid school shutdowns.