Building my first bigger genny

[ZooT]

I've been busy here working on my first big wind genny....

I'd like to follow Harrie's line of thought in that I'd like a very slow turning unit...but this will have a swing tail furling system.

I'll post a pair of pics here so folks can see what I have so far

This uses the standard 1600 lb trailer hub and axle.

The disk is 12"x3/8"(that's what I could find in the dumpster)

I mounted it, and machined it true to .002 TIR and left a .060 ridge on the outside edge to help hold the magnets in place....

I want to build a single rotor machine similiar to the Dans 7' machine and Ed's minigen200

I've got 24-2"x1"x1/2" neos with a 3/16" hole in the center, a set of 7 foot diameter china blades and a set of 9.2 foot diameter china blades along with the hubs, and 11 lbs of 16AWG magnet wire.

I'd really like to use the 7 foot blades on this project and save the 9 foot blades for the stack of 16"x1/4" steel disks I dug out of the dumpster, but if those who know more think I'll need 9 foot blades.....well then so be it.

I'm considering using 16 mags and 12 coils, each having 60 turns on them for three phases of four coils each for a low cut-in speed.

Does this sound doable?

[harrie]

I would suggest that you start by building a turbine as close to a proven design as possible, which you can do with the matl. you have gathered so far. Dan has very detailed posts on this site to use, or purchase one of hughs plans.

This way, you will end up with something that is workable, and go thru a learning process along the way and wont get depressed with the results.

To run at a low RPM, requires you to run in stall at close to or at cut in voltage, and will receive somewhat limited current. It is just a way I perfer to do it, so as not to have to deal with high RPM damage, and am satified with lower amps for battery charging. I also think you would need a larger turbine like my 18 or 22 foot with heavy blades to realize the ampreage Im getting.

You also would not need furling in a stall machine because it would not run away on you. ( at least I hope not) I have never saw any winds in my area over 40 MPH Gusts.

I have found all this to be a very educational and fun hobby, so hang in there.

[Flux]

I know nothing about your Chinese blades so I can't comment on them.

How slow you can keep things depends a lot on the blades but for a 7ft machine you shouldn't consider operating in stall like Harrie does, you just won't get enough power.

Single rotors are wasteful of magnet material but with 16 magnets I think you will be ok. You must keep the stator fairly thin and keep it close to the magnets.

I wouldn't aim for a stator over 3/8" thick otherwise you will have a lot of copper with little flux linking it.

Even with 16 magnets you may not be able to keep the speed right down and brake switches may not stop it in a high wind. It should work well enough but as harrie said you are on unproven ground. I believe Dan has done a fairly fast single rotor with 12 magnets so you should be able to manage with 16 but you will be foolish to guess turns, you will have to do some test coils.

I will look at your suggested turns to see if you are in the right league but with no prop details and the uncertainty of single rotor magnetics it will not be precise.

Flux

[Flux]

At a quick glance that looks reasonable for 24v. I think 60 turns will be too slow for 12v.

16 magnets is squashed up fairly tight on a 12" disc but it should work ok.

The #16 would be ok for 24v, probably need it 2 in hand for 12v.

Flux