Daddy said it could not be done, so I did it.

[neptune]

My dad, when I was nine, explained to me how sailing boats work. He explained that any wind powered device can not sail directly in to the wind. So I built a machine to prove him wrong. It was a simple chassis with 4 wheels, and a windmill mounted on the front The windmill drove the front axle via 2 pulleys and a rubber band. It worked. I was only nine , so I did not think about optimising the gear ratio, and the design of the rotor. It would be very interesting to rebuild this seemingly impossible machine , to see how fast it could move as a proportion of the speed of the wind. As a kid I imagined that it would work with no wind if you just started it, but somehow I doubt it.

[dirt diggler]

soooo, could it be possible to run it thru a gearbox and to a prop and actually boat around the lake-upwind, downwind, wherever as long as the windmill is pointed to the wind?

[nightlife]

Check out this video.

http://youtube.com/watch?v=XRYkIzjmCR4&feature=related

[neptune]

I had not seen that video. I reckon they have the gear ratio too low, as i seem to remember better performance as a kid. Also it would pay to use an efficient aerofoil rotor with a tip speed ratio of about 6 to1. There are loads of plans for these on wind generator sites. My interest was in land yachts rather than boats. Boats are possible, but you don't have the same positive traction or grip. Also if you wish to travel in any direction, you would need to vary the ratio [variable gearbox] depending on your direction of travel relative to the wind. Here an efficient vertical axis rotor might work well, eg Darius rather than savonius. Why not try it with a model and post results?