Converting an induction motor into an alternator (I am a newbie)

[dansohayl]

Hi,

Well, yes, I am a "newbie" as you will be able to tell from my question.  I have a strong feeling that what I want to do is probably impractical and/or crazy.  But here it is anyway.  Hopefully someone can point me in the right direction.

I am trying find a way to make a simple (but powerful) alternating generator of electricity from a squirrel cage motor (just learned that, that is what this kind of motor is called - that is how new I am at this stuff), for a small wind generator.  

I have found that squirrel cage motors (two from air conditioners and one from a washing machine) produce a very small amount of electricity (volts) compared to small permanent magnet motors when spun by hand.  However, when I take the rotor out of the squirrel cage motor and run a permanent magnet past the coils (on the inside where the rotor was) a larger voltage is produced.  

What I would like to try to do is remove the rotor and install permanent magnets on the shaft, where the rotor was sitting.  This way the magnets would spin inside the coils to produce a higher amount of volts.

Has anyone done this?  Am I crazy to think that this is possible?  Would it even work?  

If this has worked for someone, how do I get the rotor off the shaft?  I cannot figure out how the rotor is attached, and I am almost ready to try and just smash it to pieces with a hammer

What do you think?

Thanks

P.S. Remember, I am totally new at this stuff so be gentle in your criticism.  

P.S.S. As I am trying to learn how to make a homebrewed wind turbine, I have been spending way too much time (the last couple of days) on this website looking at stuff and slowing learning.  I should be in bed (its 1am) or working!!!  But as many of you know this is fun, fascinating, and habit forming stuff.  Thank you to all those you keep this service going.

[fungus]

Certainly you can. You'll want to look at 'zubbly's posts-he knows quite a lot about them and in particular his pdf guide files-found here. The rotor is usually left on and turned down on a lathe to fit the magnets. To stop 'cogging'(a sort of pulsing that affects low wind performance), you'll want to 'skew' the magnets at around 10 degrees for a 36 slot stator. If you had any pictures than that would be great.

[Flux]

Look at the early stuff on Otherpower and also look up Jerry's work on the garbogens and many other conversions.

Also I think that Ed has some details on Windstuffnow. What you need to look for is motor conversions.

flux

[asheets]

The short answer is, yes you can turn your motors into good generators.  What you've got now is that the motor coils still have a bit of residual magnatism in them; that's why when you hand spin them you get a little current out.  If you were to spin them at 110% of their rated running RPM, then you'd get a lot more power out of it as the magnet coil would start to energize (thus the term, induction motor).

Or, as is popular here, create your own magnetic field by sticking magnets on the rotating piece.  Putting them in at random will work, but the Zubbly and Jerry approaches are fine tuned a great deal more.

[alancorey]

Most of the Zubbly and Garbogen approaches require a lathe to turn down the rotor.  The trick is that you've got to make space for the magnets somewhere.  If you're limited to hand tools (like I am), some approaches are to make a new rotor on a piece of shaft that fits, or hacksaw off of the original rotor to have room.  Another might be to collect enough motors that you can take a small rotor out of one and have it fit into another with enough space left over.

For some of the hacksawing down rotor approaches search here for boxfan conversion, by ghurd.  Here's a pic of a rotor I hacksawed to mount 4 magnets on: http://www.otherpower.com/images/scimages/6871/berns_ground_mag.jpg

  Alan

[ghurd]

Here's my box fan post.

http://www.fieldlines.com/story/2005/7/4/34446/17324

Here is a more normal motor, armature cut down in a lathe, hard drive magnets epoxied on. (its a wide pic)

http://www.otherpower.com/images/scimages/2050/3phHD.jpg

Neither is great, but both were easy and work.

G-

[JW]

Look at the early stuff on Otherpower and also look up Jerry's work on the garbogens and many other conversions.<p>
Also I think that Ed has some details on Windstuffnow. What you need to look for is motor conversions.<p>
flux

https://www.fieldlines.com/index.php?topic=148090.0

[SparWeb]

JW,
Thanks!
That's a fantastic blast from the past.