A friend has been playing around with an idea I had for a canted sail and has built a quarter scale model of a 7m beach proa he is thinking about building. There is a video clip of testing here:
The controls are still a bit coarse and rig too flexible but it sails quite well and responds quickly.
The aim with the canted bi-directional rig is to get better alignment of drive and drag forces in 3D. The flexibility of the rig tended to reduce the vertical component of the sail drive. Also the sail was a bit large for some of the gusts. A smaller sail could have increased canting angle to improve the vertical lift component. In addition the mast could be canted to the windward side rather than being vertical to give more vertical component to counter healing.
Rick Willoughby
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