Yes, but even low cogging outerrunner brushless RC motors  (12 tooth/10 or 14 pole and 9/8 ... 9/10 ... 18/16 ... 18/20 ...)  have cogging too much for small windmill - it will not self-start. And those motors are cheap but not very cheap ---. $30 for tiny ones and up to $300 for larges. Tiny ones has tiny bearings and thin shaft as well. At that kV of these motors is at 500 to 3500.  When kV is 1000 then you need 1000 rpm for get one Volt !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
regards,
khabe

I have a small outrunner from Hong Kong about $15 on ebay and yes I notice it has noticable no load cogging even though it has different number of poles to mags? I think a wind turbine of a couple feet diam would start one running though.

You´re right the kV on the normal model motors is too high for direct to turbine and cogging will amplify through gearing.

I suppose a rewind with finer wire for lower kV would help but then that´s a fiddly long winded job.

Yucca.

I guess I paid about 2 dollars for this little motor that makes a pretty good demonstrator generator.
We're not trying to save the world from the tyranny of oil, here, we're just trying to help a kid do a science fair project, and I have a hunch he's not (yet) attending MIT, so it doesn't have to be too complicated.
Neither does it have to be the most efficient generator, or the fanciest technology.
A mechanically commutated DC motor won't require rectification, and if the right type of motor is chosen it won't exhibit "cogging" or excessive bearing drag, and so will be easy to turn with a wind turbine or water wheel or even a hamster in a cage, without complicated transmissions or gearing.
And a demonstration using this kind of motor will give the presenter ample opportunity to discuss issues of overall efficiency, ease of construction and maintenance, environmental impact, not to mention the physics of electromagnetism.
http://www.youtube.com/watch?v=kFavcqNWF5I

make instead electricity compressed air.
and drive your car with this

http://www.brasschecktv.com/page/456.html
Source BBC-News Car 120km/h speed !

Gustav Pese

All energy that make noise, have to mutch losses. Regardless of whether piston or turbine propulsion. Similarly, it is certainly possible with a  sound insulation to build. Some Honda generators show the possibility as there is. Certainly, it is possible to progress. Pese

P.S. I  womder that nobody have think about to reduce the coists and losses -for- compression the air. I look for contact to figure that out.
 

Perhaps take up with compressed air is not prestige enough - there is no orotund sounding therms and words - no ether ... fusion ... scalar ... essential ... 
Is it too commonplace, cheap and bathetic At that it needs attend school ...  and it needs much more precise work - no fluttering wheels, no crooked shafts 
when making compressed air. And pressure is dangerous ... especially when education has been poor
gruss,
khabe

education for poor folks
google make it possibel

http://www.google.de/search?hl=de&q=turbine+compressed+air+generator&meta=

GP


And here some adds.
from my link collection:

http://rexresearch.com/negre/negre.htm


PS.
If you can handle
butan/propan camping gas (12 bar)
than you can handle , lower pressured air....

Hi Thaelin -

One implementation of the  12mag - 9 coil setup is in the axial flux dual rotor design.
The idea of the dual rotor is eliminate iron in the stator and then maximize the flux in the airgap between two rotors of magnets.
If iron is used (should always be so) as a backing for each rotor, the 'magnetic circuit' is completed - boosting flux.  (the flux from the backside of each magnet is 'channeled' to flow back through the adjacent magnet and back through the stator)

The problem with a single rotor/dual stator design is the incomplete magnetic circuit.
One would think that putting coils next to BOTH faces of the magnet would offer superior performance - but that is not the case.

I have just completed my first axial flux dual rotor build. (Hugh Piggot style design)
1. 12 mags 9 coils
2. .75" x .5" N42 mags  :  1/4" steel rotors
3. 500 turns #24 AWG coils .75" ID x 2" OD x 7/16"
4. airgap from each rotor to stator 1/8"

The magnets were taken from a build I did 2 months ago of a single rotor/dual stator design like you describe.  The coils had an iron core.

Comparing the two:
1. The dual ROTOR generated TWICE the power
2. The dual ROTOR resulted in around FOUR TIMES (or more) LESS drag. (no iron in coils)
(so at least 8x better performance)

For a long time I was of the notion that putting coils on BOTH sides of the magnets would be best - even though I'd been told it was not so as the 'magnetic circuit' was incomplete and thus inefficient.

Having now built BOTH designs - I can say that a DUAL ROTOR is SUPERIOR in many ways over the dual stator.

My next build of this design will use larger magnets (2" x 1" x 1/2") , 16 mags 12 coils with larger wire (#18 AWG?) and 1/2" steel rotors.

The Fisher Paykel washing machine motor makes a good generator.  Here is a complete detail plan for a windmill from downunder:

http://www.thebackshed.com/windmill/fp2a.asp

Elsewhere,

http://www.watchtv.net/~rburmeister/smart.html

others recommend grinding the edges of the cores of the electromagnets to reduce cogging.

Terry