Recent content by ferrand

Ron, Geebee, Have a word with Ken Visser, on http://people.clarkson.edu/~visser/ he built a contra unit from a Marlec axial flux machine, 2007 Jan report on his websits Re Trimble & alternators, a central magnet rotor flanked by two contra rotating coil rotors gives a very elegant unit. Given...

Ron, Something like what you are proposing was put forward by Honneff about 1933. I will try and find a reference, but I suspect that there is nothing about this on line Henneffs 1932 book Windcraftwerke may have it in. Only place I know of a copy is in the Science Museum Library, London His...

How small ? Original Trimble test unit was 1.5m dia, normal machine 6m, rated 5 kW @ 10m/sec wind Might find a you a second hand Trimblemill in Ireland for you to play with ? Or UK manufacturer of axial flux alternators might help, after all a contra rotating WT is but an "alternator with wings"...

geebee, I know the Selsam set up, it demonstrates the benefits of multirotor "arrays" to keep costs down. As far as I am aware they are single rotor. For a picture of an actual operating contra machine - timblemill - there is one on the earthtoys URL I have a lot of other data/pictures...

What few realize is that much work on quite large contra rotation wind turbines was done by the Third Reich Wind Energy Ministry, 1935-45, and later by Trimbles Windmills, see this URL http://www.earthtoys.com/emagazine.php?issue_number=07.04.01&article=contra See also...