Hi
I have been constructing my wind generator for a while and am about to make the blades. The dual rotor alternator has 16 25x50x15mm (1"x2"x.5") magnets and 12 coils of 50 turns of 1.8mm (13AWG)for a 24V machine. When I saw that Hugh's new plans had a machine with the same specs as I had I ordered it right away and it arrived within 3 days (This is amazing as post here usually takes at least 3 weeks) I designed the rotor and magnets over a year ago, and had them laser cut, with holes for cooling. They are a smaller size than in Hughs book , at 330mm (13") diameter but While at it I also had them cut the bracket for the stator, just made putting it together a bit simpler.
My Generator (this is a 1953 lister diesel 6hp motor I connected to a large 3 phase alternator I also bought second hand) only just has enough juice for welding, so I decided to have the pieces welded at the local exhaust shop for $10, I think this was a smart move.
I had miscalculated the thickness of the rotor mould, adding a mm instead of subtracting a mm, resulting in a mould that was 2mm too thick, fortunately the steel I used to hold the lid down lifted the entire rotor, so I only had to chip off 2mm of resin on the back of the rotor.
I used 1.8mm wire with 50 turns and tested a single coil, calculating what it should produce is complicated but I searched the board and found all the equations. I have now tested it by hand spinning with the rectifiers attached and it gives me a cut in of 24 Volts at 120rpm. I found the coil winder I made worked really well although I did struggle a bit to keep the legs the same width.
I am looking forward to carving the blades as I like working in wood. I have laminated a whole lot of second hand door frames (a good source of oregon pine) together. I weighed each piece to ensure the rotors are balanced and was amazed how much the wood differed from the lighest piece at 4lbs to the heaviest at 6lbs.
At the moment we have our windiest month, so feeling a little frustrated at not being finished.
Paul
