This is the earlier history of the downwind vertically driven shaft windcatcher and how I arrived at the final design for The Flying Lizard.
The name comes from the small lizards sucked up into the dust devils that frequent the Northern Nevada desert.
This first illustration is a necessity for anyone that whats to design a homebuilt windcatcher for the area he lives: the Windrose.
The WindRose tells you the prevalent direction and velocity of the winds in your area. They are usually available through NOAA.
Step 1: Doing the Math
Here's one of the first things the wind catcher will have to deal with. The Laws of Physics and how wind towers fall down. There's some important advice in the pdf file.
Step 2: How not to make your windcatcher hum...
Probably the primary reason that a tower will fall is like tuning a guitar. Actually its best to untune the guitar.
Another pdf file on how the first Flying Lizard was built, and its rather strange way of transmitting power, via a flexible power shaft.
Step 3: The First Flying Lizard Power Transfer System
Its simple. A 1/2 inch conduit elbow tranfers rotation vertically with a door spring and an inside aircraft cable. Lubricate the sliding areas with graphite. At the speeds the windcatcher runs at, there's not that much energy loss.
Step 4: The top of the tower
The whole asssembly rotated on a lazy susan bearing, the rotating spring went through the whole in the lazy susan.
Step 5: Up and running
Here's what it looked like in the winter of 2006-7. The sails are made out of old campaign signs, they held up remarkably well. The main problem with this first device was not enough leverage to turn the sails downwind when the wind shifted.