My first Wind Turbine

[coldspot]

"attitude"

Wow

Even this site gets a bit full of it

I see now

 

Anyway

My $0.02

So, you want a few K's of power

Why make it from just one mill?

If you had a few mills and they

all added up to make this amount

I'd think that you'd be better off if

one had an issue and the others still worked

Besides building one is like saying

i'll drink just one

Not going to happen. LOL

Anyway, you won't build just one

so why not just start with a 8-10'

(Way to large for my first try){Dual Rotor}

And have twice or three times the fun you would have had building just one

cause you will build more anyway and having a few up is better

than just one.

Like you said, have some FUN

[commanda]

What this site needs is a "user profile". All new users should fill it out (mandatory) before posting. Murlin is not mechanically inept, as far as I can gather from what he's posted. Over-ambitious maybe, but honestly, who isn't.

Problem is, it takes a fair range of skills to successfully build a wind turbine. Few newcomers to this site are likely to have all the skills straight off.

So please, let's enlighten newcomers with the depth of our collective knowledge, not jump down their throats.

My 2.2 cents worth (includes gst).

Amanda

[WXYZCIENCE]

Murlin, We can build you a black box that will tell you why you unit crashed. All windmills are experimental! I am building a big one 8'. For me this is touching on the limit of my ability. If you can build such a big one I hope you have success. If not, failure is not such a bad thing. At least you will know what not to do the next time. Joe.

[hiker]

i always try to think safety-in the things i do and build..

damm--but i still managed to blow up a exersize bike..close call..

mags flying past your face at a couple of hundred miles an hour..

really gave me a wake up call..go ahead build it --but build it right--

you may not get a secound chance....hey welcome to the board...

[Murlin]

Yo, dinges, did you even check out the link to the epoxy I put up?

These guys claim that it has the best thermal conductivity with extremely low thermal expansion. No one has even commented on that. So mayhaps the mags wouldnt seperate with such a material as easily as just using plain epoxy.

If you put small fins sticking out of any material, heat will go TO them.  

And since they are of small area, they will be cool down faster. Especially since they are sitting in front of a fan.

Any 3-phase motor I have ever seen has cooling fins around the case of the motor.

It just made sense to me that any small amout of heat that could be drawn away from the stator would only help things and could not hurt in any way, shape or form.  I mean you just cut some groves in the mold, it's no big deal at all.

Of course, epoxy is a bad conductor of heat. That should be a given. but that said, there are all kinds of epoxies out there, and some are sure to be better than others at dissapating heat.

Flux has been voicing his opinion in many posts of his about the heat that is trapped in the stator by having them incased in epoxy.  Others have put holes in the middle of the coils to try to dissipate some heat, so I think heat is an issue since so many people are talking about it. Just an observation.

Since these alternators are basiclly all experimental anyways and none of us first time builders have the expertise to make the perfect stator the first time out of the box.

And I guarantee, all of them will get hot.  If you can dissapate any  % of heat with very little work, I just thought it would be a + and not a -.

Murlin

[dinges]

Assuming that all posters fill this in honestly it might be an idea. Though I think that only over time we get to know the various posters good enough (from experience and reading their posts) to be able to start judging correctly. Also, the posters that remain on this board for a longer time generally show they are really committed. Anyone who subscribes to this board and makes his first post 'I want to build a 20ft genny' (I'm NOT talking about the original poster here, BTW) arouses my suspicion. The question on furling/shutting off in 'high winds during the night' didn't help much either.

The way the original poster inserted his 'scope' remark made me very wary. I thought he was showing off that he had a scope, to show us that he had 'the' tools for the job. Apparently I misjudged his intentions.

You're right, it's very difficult to judge someone's capabilities and knowledge from a distance. The fact that he has access to EDM and CNC mills and/or lathes indicates he's at least mechanically able. As far as his electronics knowledge goes, I'm not impressed, despite his troubleshooting successes. The good thing is that very little knowledge on electronics is needed for building a windmill. Just about anything can be done with a (cheap) digital multimeter.

Still stand fully by my original remarks on beginning with a 20ft machine. But this is based on my own experience, knowledge and my generally conservative nature. Other people may be completely different.

BTW, I don't feel we were jumping to his throat but telling him that it might be wiser (from our collective wisdom point of view) to start with something smaller. But then, I'm not Texan

Peter.

[Murlin]

Man this is a tuff room....

User profile eh?

Ok I will tell you guys a little about myself.

I think you may be in error about my mechanical skills

 I started off by building plastic and die cast molds.  Built a few progressive dies and rubber compression molds.   Did that for about 10 years.  I can mig,tig and arc weld, and have all three machines. Being profecient in precision form grinding, I have held tolerances of  + or - 50 millionths...thats .00005.  In a controlled environment.

I am an expert in  the machining industry.  I am profecient in mills, lathes, grinders,EDM machines, and can build my own computer  from scratch and have been for 25 years.

Over the past 20 years I have owned and operated my own business, and still do but on a smaller scale than I have in the past. At the present time I am in the forging industry and am doing CAD-CAM for a company taking old blueprints that were done on the drafting table back in the 60's and re doing them in CAD.  I do tooling for aluminum and steel forgings, that makes parts for Lockhead Martin, Bell helicopter, Boeing and several others.  I design the tooling for numerous forgings in the mining and Rockbit industry.  I have worked on alot of tooling for Howard Hughes designed drill segments that drill oil wells.

I also made the tooling for a number of years for the Bulldog Trailer hitch parts that are put on most of the horse trailers here in Texas and around the country.

Last year I designed the tooling several crankshafts, including the the new Ford Big Block for new Shelby.

Below is a pic of the last one I did and I have he prints for another one up on my wall right now that I am starting on.

It is fairly conmplicated stuff, just in a diffrent field from all you electrical Guru's. I never clamed to be Einstien...

When I first found this board, I was VERY impressed with the brain power in this room, and still am.  I would not be in here otherwise.   This place has the info I need to accomplish my goal of off the grid living.  

Anyone who wants to help me, it is extremly  welcome. I will be more than happy to to help anyone that wants my help.  

Some of you guys need to lighten up.  You take life WAY to seriously.....

Murlin

[Flux]

Murlin

I am not sure how good that epoxy is, but it will be a step in the right direction.

Any heat that you can remove will be to your advantage. I thought your original intention was to conduct from the epoxy to an aluminium heat sink. To do that safely you would need to keep it so far from the magnets that it would be of little use. Casting fins on the epoxy is fine.

In a dry climate I think you will manage without encapsulating the magnets and the fan effect will be advantageous if you can devise a way to get air into the center of the magnet rotors.

As you are aiming for maximum power in low winds and are not too bothered about the higher winds you may be able to use stall to your advantage, and that combined with good furling should mean that you will not need to shut down under normal conditions, but there is not much to be gained by trying to keep things running through a storm.

I like to have a means of turning it out of the wind to stop it, others are happy to trust brake switches.

Flux

[Murlin]

I have been doing some research on these magnets you guys are using.  Since they are fairly costly, I want to be sure that I get the right one for my application.

I came across these specs.

MAGNETIC PROPERTY OF NEODYMIUM MAGNETS

Grade     Br (Gauss)     Hc (Oe)     Hci (Oe)     (BH)max (MGO)     Max Working Temp. ( °C / °F)        

35.     11,700 - 12,100     >10,900     >12,000     35     80 / 176        
    
40.     12,500 - 12,800     >10,500     >12,000     40     80 / 176        
    
35. H     12,500 - 11,700     >11,000     >17,000     35     120 / 245        
    
35. SH     11,700 - 12,500     >11,000     >20,000     35     150 / 300      
    
    

I am assuming that the large magnets of Forcefields page,  are the ones at the top judging from the spec's on their website.

So I have concerns on using those magnets in my area due to the fact that it gets about 120 degrees F in the shade in my area 6 months out of the year.

Looks like they are protected from the elements pretty well by the nickle coating,  But I am thinking that a large mass of metal,  sticking up there in the sun would already reach 150 + degrees F without doing any work at all.   When they start working, could perhaps exceed the max temp rating and start to demagnatizing.

I know in theory that in theory, a well built alternator, should not produce much noticable heat, but most of those tests have been done in the shade of the

lab without any heat from the sun factored in.  And I hardly think I have the expertise to produce a unit that would run with zero heat....

Just my thoughts on the matter....I am going to inquire about the better grade.....where the max working temp is 300 degrees F.

Murlin

[QUAZ HOLT]

Hay Magic-man, I used to a Genius also, but I'm all right now. QUAZ

[kitno455]

if you leave the mags sticking up some (both flux and i mentioned this) you will get some cooling effect, cause they are spinning. if you can manage to get some air into the center thru holes in the rotors, you should not have much trouble. big steel plate helps conduct heat too. it will be a bit like a vented disc brake rotor.

there have been a couple cases on this board where mags lost their strength. likely causes mentioned are 1. sudden shock, (dont drop them, or have them slam into a stop)

2. heating from friction with stator (stator warped, came loose, etc)
   
3. heating in stator heats the mags without contact (less likely than #2?)
   
   

are there any others?

allan

[Flux]

You may be justified to think about this if you have a high ambient temperature.

If the H grade are not desperately more expensive, they would make sense.

The temperature at which loss occurs depends on how they are influenced by demagnetising fields. The 80 deg c figure is with a demagnetising field taking the magnet well to the left on the demagnetising curve.  With an air gap design you are not likely to push it into this region, so you may not see trouble until perhaps 120deg C.

I am not sure how much of the stator heat reaches the magnets, not much I suspect, but a small cost increase for the H grade may bring some comfort.

Most cases of demagnetising are from abuse rather than normal operation, but this issue with neo is always present, but as manufacture improves it becomes less of a problem.

Flux

[Murlin]

Thank you for your help and advice .

I sent an e-mail inquiring about the H magnets, but I think I am being overly cautious.  But we do have about 30 days out of the hottest part of the year around here, where there is almost zero wind and the mill would not be moving at all.  Just stuck up there imitating a heat collector and those are the days I was concerned with.    I don't think it will get 120degreesC(248F). and I have the cooling situation well in hand.  

Since DanB has given me so much valuable free info, when I get done here, I will go ahead and place an order for 42 of them(a couple extra incase I break one).  I like what he is doing and will support his business as much as I can.

I almost have my geometry done for the waterjet.  When I get it done I will be willing to share it with anyone who wants it......who knows....it might work

So here we go

Ihe Journey begins........

Stay tuned

Murlin teh beam me up Scotty........