A recent scratch built glider kept turning to the right even after painstaking efforts to match the wings perfectly. Extensive addition of fin area to the tail failed to correct it. Closer examination showed the left leading edge had been carved to a sharper point, angled more sharply than the curvature of the wing.
After carving the right LE to a point the glider flew perfectly straight.
This was not expected at the 5-7 mph the glider flies at, and the effect seemed to be stronger at lower speeds.
Could sharper leading edges help even at very low speeds?