I had a book no longer in print called Windmills of Nebraska, which was very good. Loaned it out and never got it back. It was a reprint of a 1880's manual put together by an agricultural agent who was fascinated by the ingenuity of the local farmers and their homemade windmills. In the 1950s when I grew up there were many working around the neighborhood. The Nebraska Windmills, Circa 1870, originated in the middle ages centuries ago. They were used in castle towers for the purpose of pumping water. They had bucket pump type systems that was a continuous chain of buckets on a rope type belt that dipped into a well or cistern and on up to pour into a water tank run over wood pulleys. Another major use was grinding grain into flour. They were also used to power tools, shops, and electric generators.
To shut down the windmill you can apply a break system to one end of the axle or enclose the windmill with doors that can be opened to allow wind through, or shut to stop the wind. It doesn't work only in one direction, it works in about 6 angles, but half of the time rotation would be in reverse, which doesn't matter if you're grinding grain or pumping water. Most of our wind is prevailing westerly. If the axle runs north-south, it won't work in north or south winds.
wind>>|plywood | ------| | |o| |fence | -------| | | | | | | --------------------- ground
They would be cheap and easy to build from scrap lumber with a little imagination. The
paddles could be as simple as 2x2 board frames covered with cloth like canvas, etc.,
which would cut costs. Could use a 8 ft. 4 x 4 for the axle. Mount 2 steel shafts on the
ends where it will mount in bearings. Use a pipe flange and a nipple at the center of each
end. Insert a round steel shaft in each end long enough to clear the pillow block bearings
needed at each end to mount the shaft and take off power by a large pulley or crank. You
can put one on one end and one on the other. (this will run at around 300 rpm). Mount a 4'
by 8' sheet of plywood on each side of the axle shaft to form a turbine. Then you will need
a board fence all around the windmill from the ground to the axle, so the top blade of your
turbine will be exposed to the air. Also, note that the bearings are mounted each on top of
A model (working) could easily be made with a card board box. Make the turbine to fit your box. That would be a good way to test it. Held together with bolts and balanced so as to not fly apart under high wind conditions. Don't nail it together it will soon fall apart if you do. I estimate about 200 dollars to build it.
Offered by Darrell.