I was asked to present some alternative energy demonstrations for the Thompson community day celebrations, so I decided it was time to build a wind generator to complement the many solar demonstration devices I have. As usual I did some research on line and found some interesting DIY websites that had some interesting information. I only had several days to build the device, so I had to wing it with components that I had on hand. I selected a surplus PM dc motor as the generator based on some output test in the lathe.The motor that was selected will output 15V at 1000RPM, and since I had no idea how fast the thing would actually spin, I figured that it would be satisfactory for a demonstration system. I saw that many people have fabricated blades from PVC pipe, and I happened to have some 12" schedule 40 pipe so I started with that. After carefully cutting out the blades, and starting to shape them, I decided that the PVC blades would be too heavy, and would not be very pretty for the demonstration. I put them aside and cut out some laminated wood blades from an engineered wood beam that was left over from an addition I built several years ago. Several hours of sanding and shaping, and I had four nice looking light weight blades. I welded up a hub with some hardware that I had, and made the hub so the blade pitch could be changed and simply locked into the new setting. I balanced the blades, and built a slip ring assembly that fit on the end of an old windsurfer carbon fiber mast. The mast is attached to the demo trailer that we use for alt energy events, with some stainless steel hose clamps. The blog starts at the community day at the bottom of the page, with the latest entries at the top.
The hub
quick and dirty adjustable pitch hub
Details of the welded hub
(Posted 10/10/2009 by mikey)
a better generator
better generator
I dug a bit deeper into my motor pile, and turned up a beauty that was bought at the MIT fleamarket. It has 10 times the output of the present motor. Back to the machine shop.
(Posted 10/10/2009 by mikey)
Taking data towards making this a real wind generator
test day 1
I spent a nice breezy fall day taking data on the wind generator. I definitely need more output voltage to be useable in light winds,my initial test was behind the garage so I would be shielded from the 35 mph gust. My back yard is surrounded by trees that are 70-100 feet tall, so I was not able to get into the real wind, but was able to get some useful information. I never saw more than 1.5 V on the output. Pretty low, and not much good for generating serious power. I suspect that had the thing been on top of a 200 foot tower, it would have been really cranking.
(Posted 10/10/2009 by mikey)
First wind generator
First wind
I stayed up until about 3 AM the night before the community day event and got everything built and assembled, but had to wait until we set up the wind generator at the event to see how it worked.The wind was very light but the thing was spinning at 30-60 rpm. Lots more testing and tweaking to do before this thing is ready for permanent installation, but this was a good first step.
