a fresh start

[ZooT]

Having played with a box fan conversion with somewhat limited success, I've decided to go the full route and build a homebrewed axial flux wind genny.

I figured I'd post a pic or two of the raw genny rotor assembly for comment.

The shaft, spacer, and all the hardware is stainless, and in fact all the mounting gear is also going to be stainless.

The rotor disks are 8" diameter and 1/4" thick as per info provided by others here, and the input shaft is 1" in diameter.

I've also got a 4 blade 7'er uh......rotor/blade set, but it's dark here and I can't get far enough away to take a decent picture of it*grin*

It also has a stainless hub......

[ZooT]

Oops.......got a pair of pics I forgot...

[ghurd]

Wow!

Thats sure a big step up from the box fan!

Is there an adjustment somehow for the air gap?

It's too late for you.

You have been infected with the bug.

G-

[Experimental]

     Very nice, and I commend you, on the use of stainless -- was concerned when I read that, untill I saw the pics -- As the discs, appear to be mild steel !!

     Stainless, of course would not work, for discs, as they would not be magnetic!

     As I live in the state of Washington, rain is a real producer of rust and I hate rust --- so my next mill, will be stainless  as well !!

    As Gurd asked, how will you adjust the air gap ??--- Looking at it, I assume, shims !!??   And what magnets ??

    Very nice start -- keep those pics comeing -- Bill H.........

[ZooT]

Nope no way to adjust airgap......yet.

Think I'll look at how others have done it and decide what I'm going to do about air gap adjustment as I get further along.

Still have to acquire magnets and some heavier wire as all I've got is about three pounds of #22AWG here

I'm going to use "stove burner covers" for a mold to cast the stator and modeling clay to form the hole in the center of the mold

The threaded rod idea sounds good and all I'd have to do in this case is turn down the face of my spacer to incorporate it into the design.

As the spacer and shaft are stainless it's pretty heavy and cutting an inch or so off the thickness of the spacer would lighten it up a bit.

[MountainMan]

Looks like a good start.  I just wanted to bring up something that I've seen people have trouble with in completely different situations (deck fasteners), and see what the experience of the mill heads around here is on this.

It seems that you can get yourself in real trouble using stainless nails or screws to fasten the galvanized steel brackets and hangars, etc. that are used in constructing a deck.

A handy website I found that talks about the galvanic potential of different dissimilar metals is here:

So it seems from that website that there is at least a potential (pardon the pun) for a dissimilar metals problem with a rotor like this one.

What is your experience with this?

thanks,

jp

[wdyasq]

Not to say that site is wrong .... but you can't put enough inforamtion in one page to explain a lot of the problems in metal corrosion.  Not all problems are galvonic or even directly related to the galvonic scale.  

Stainless steel is one of my least favorite fasteners in boats.  Brass fits this bill too.  There is a reason the old boats were built with galvanized iron or high-copper alloys but not both.  

The best alloys - IMO - for wet wood contact are either bronze (high-copper) alloys, copper-nickel or nickel-copper.  A great deal of work goes into eliminating as much metal as possible in a good plastic(if there is such a thing as a 'good' plastic boat) or modern wooden boat.

'It seems that you can get yourself in real trouble using stainless nails or screws to fasten the galvanized steel brackets and hangars, etc. that are used in constructing a deck.' - my bet, and I haven't seen the failure, is it is more likely 'crevace corrosion' rather than true galvonic problems in this case.  The causes and cures are beyond what I care to relate (and would go into pages of information, most of which would likely be miss-written or miss-understood, madams of the local house of ill-results).

One decent book is 'Metal Corrosion in Boats' by Nigel Warren.

Ron

[ZooT]

>-- As the discs, appear to be mild steel !!

Of course the disks are mild steel*grin*

I might not know an awful lot about this stuff yet, but I can read, and everywhere on this board there's references to using magnetic material behind the magnets.

Anyways I plan on shrouding the steel rotors and the stator and leaving only stainless exposed to the elements.

As far as dissimiliar metal reactions go......I'll worry about that if and when I see it....and in fact I worry more about the lifespan of the wooden blades than I do about the lifespan of the material from which the genny itself is constructed