My attempt at a dual rotor

[bug bit]

#24 magnet wire. 450 turns per coil. 1 x ½ x ¼  neos.  9 coils 12 magnets per rotor. wired 3 phase star.

7 1/4" saw blades. I used a blown up fan motor for the shaft and end caps and put it all in a box.

The air gap is huge, but it will hit 13 volts open at about 50 rpm. No idea if it is even putting out amps, I kind of doubt it. I'm still trying to figure out how to measure past volts. But I'm learning as I go. It will stop hard if I short the wires.

Now I need to study more on what Windstuff Ed has posted about the Lenz Blades. I am thinking 2' by 2'.

[windstuffnow]

  Nice work on the alternator!   The 2x2 will do about 25 watts in a 15mph wind... should have no problem turning your alternator.  Sounds like your coils might have a considerable amount of resistance and may not produce alot of power but it might surprise you.   It'll be fun to see it go !   Let me know what information you need.

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[bug bit]

Thanks Ed

on top of it right now is 18"x18" from your dimentions. doesn't seem to be catching much wind and there isn't any power to it. Have to go bigger.

they are made with plywood ends, and .100" thick plastic. they put it between pallets and the product. seems strong, just not big enough. oh yea, ugly too . i put a 30 second movie in my file uploads. i just feel it takes a lot of wind to make things happen.

[willib]

"It will stop hard if I short the wires."

thats  a good sign !

It shows a correct relationship between magnets and coils

 keep  up the good work..!!

[powerbuoy]

First of all, ...nice job. I wonder ... the picture makes it appear as if the coils are glued in between two plates, is this correct? They also appear to be aluminum? Did you cut a big circle in the plates and filled it with epoxy, so that the magnets hover directly over the coils or are the magnets hovering over the plate and the coils are hidden underneath the plate?

Powerbuoy

[willib]

it doesnt play it just sits there:(

[bug bit]

The coils are glued to 2 pieces of plexiglass top and bottom with 5 min epoxy. Everything is held in place with 4 brass threaded rods on the outside edge of the stator. The outside edges of the box keeps everything in place. guess i had trouble thinking outside the box

[windstuffnow]

  For some reason the dimensions don't appear right in the vid.   Looks like its moving fairly well.   Do you know what the wind speed was ?   In a 10 mph wind it should make in the area of 4.5 watts and at 15mph about 15 watts.

  The wing width should be 3.375" wide and from nose to trailing edge should be 7.25" long.   Just looks like you have to much empty area in the middle.  

  I have noticed after building a small one ( 12 x 12 ) that the wing angles play a big part in making them work properly where the larger ones are a bit more forgiving.   You might change the wing angle from 9 degrees to about 14 degrees or somewhere inbetween.

  Did I send you a wing drawing for size and angle?

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[bug bit]

The dims are straight from your postings. I have read them all dozens of times.

3.375"(wide) x 7.25"(long) 8.5" from center shaft to center of the wing (17" total ). I got tunnel vision at 9deg tail towards center for the angle. I will try turning in some and see what happens. You didn't send me anything but I would love to see anything you are willing to share.

The wind was really gusty. Weatherbug was saying 10 to 25 mph. (using a 5 second timer I was getting between 7 and 8 turns most of the time)running about 85 to 90 rpm. Hooked to a 9volt Dewalt battery. I ran all afternoon and the battery only gained a couple volts. And it still won't turn the drill.

[windstuffnow]

   Being close to the ground with lots of obsticles you were most likely getting winds much less than weatherbugs readings.   They usually take samples at 30ft or higher.   It may have been actually running in a 5-10 mph wind.  Your coil layout is most likely in the range of 18 ohms wired in star using the high turns of 23 wire so if it was making 3 watts over a 5 hour period you didn't actually put much into the battery ( it is rectified right? ).   I calculated it would run at around 90 rpms in a 6 mph wind with a load.  Sounds like its in the ball park for speed.  Your dimensions sound like their right on the money.

    I uploaded a dimensional drawing that helps explain the wing angle as well at http://www.otherpower.com/images/scimages/15/wing_dimensions_and_angle.JPG

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