That's it! You have a crazy renewable energy source of perhaps dubious usefulness. BUT there is a lot more that can be done. I'd like to throw out a few suggestions to the crowd for thing to try:
- double up the magnets and coils. Put one set on the bottom and one on the top. Wire the DC output of each in serial and double the voltage. Hopefully.
- bigger, badder coils. Really see if you can up those wraps to a crazy degree. I think that's the key.
- take a look at the mintyboost USB charger (http://www.instructables.com/id/EGBQJPLCB2EP287KTZ/). I've spoken with the inventor herself, and she says that the circuit that drives it can work with input voltages between 1.5 and 4.5 volts, with the most efficiency in the middle of that range. It produces steady 5V power off of two AA batteries (which are only 2.4 to 3.0 volts). If you have this project with that one, do you get a wind-powered iPod charger? Try it and let me know.
- try a different bearing. My big thing is to use as simple and readily available parts as I possibly could, so I swore off fancier parts. You have no such limitation. I have it on good authority that skateboard bearings would be great for this. Or some other kind of bushing. Let me know what you come up with (especially if it's hacky, cheap, and better than what I've done.)
- Small lazy susans are available at art and sculpture supply stores that might also make good bearings.
- Made a bunch of these turbines? What happens when you wire them together in series? Can you make a "Pleech" farm?
- There's another more efficient Vertical Axis Wind Turbine design called the Darrieus Turbine (http://en.wikipedia.org/wiki/Darrieus_wind_turbine). It uses lift instead of drag. If you have an easy way to modify this turbine into one of those, drop a comment down here.
What I'd really love is for this to be the first (well, second) version in a long series of continually improving small turbines, the goal of which would be to power small devices (phones, sensors, art projects installed on public buildings, etc.) So, what did I do wrong? And what could be done a whole lot better? If you have answers, let us know. Hopefully, we can "crowd source" a way to make a pretty decent, and fairly cheap, wind powered generator.