car alternator to wind pma generator, stator ? to 8 n48 magnets

[chris]

 Can someone help me with my generator.
 I'm stuck at the stator winding. I have the 13 blade and hub Gen 4 raptor set from missouri wind and solar.. and my pma rotor dia is 4.475 with 8 n48 neodymium magnets. They are 1.in long x 1. In wide x. 75 thick on the rotor, and the are magnetized thru the. 75 . .. my question is how do I wind the stator for this. I know I need a 3phase ac star(  y)  configuration,  But I want the best output possible..I'm not sure on the rpm for the raptor blades yet . I do have an average  speed of 10 to 20 miles per hour .I just don't know how to wind the stator at all... I'm a newbie at this and this is my first try at this.. p.s. the stator is now empty of the original coils , that were .070 in thich...I need to know how many coils,  and if in series how do I do that. I could use a sketch or a diagram of how to wind the stator coils.  Does anybody know what the 13 blade  will give for rpm and what it maxes out at..   also I plan on using a grid tie inverter.  Do I need a 12 volt or a 24 volt system.

[Bruce S]

Chris;
The picture and your post. Is this the pre-cleared up ? Alt or ? .
I think from your posting it's now empty of the wires correct?
And did you really mean to say 13 blades?
Just kind of clearing up a few things.
What kind of range of output are you looking for?
For us to give you decent suggestions we need for you to make the decisions.
Why do you want to grid-tie?
I do have to warn you though, the MWS is NOT currently highly regarded as these units do not have a high output as of yet.

Bruce S

[chris]

Hey bruce and thanks ....yes The wires are now gone from the stator. And this is my pma I'm making.  it is not from mwands.  I am a machinist with access to the shop. I pressed off the old electric magnetic and pressed on my new rotor.I have seen all the posts about mwands too. And yes I did say the 13 blades. I was hoping for 500 Watts +

[chris]

I wanted to gridtie to offset my electric usage.

[Bruce S]

Chris;
I see a name plate on that new pic, can you let me know what it says.
Grid-Tie, MAY not be your best use of this.
Numbers time.
Say this little puppy is wired and running 12Vdc and it is or was rated for the normal 60A for use in a car running of the belts.
That would be about 700+ watts running flat out at best, the car belts have these running around 2800 - 3200 RPM.
The blades at best will probably only have this running at a safe speed of maybe 1000RPM more like 200RPM at best.
Even at 24Vdc you're going to be hitting the same problems.

The biggest problems I see are that maximum surface area that the wires and Mags have, there just isn't enough room in the casing.
Since you have this assembled, and you're a machinist, chuck this Alt up in a lathe so you can run at a known speed , grab a near dead battery some meters and give it a spin. You may see that it would be best to use it for a few circuits in your garage or to use as a starting platform for getting an understanding of what's involved.

I'm not in an area where those 13 blades can be used , but can you post the  Diameter of them?
Other may be able to help point you in the right direction.
Cheers;
Bruce S

[chris]

Here is the link to the blades. 13 generation 4 raptor hub and blades

http://www.mwands.com/index.php?main_page=product_info&cPath=43_44&products_id=471

The blades are a 59in dia.

It was a 60amp alt ,but the windings are now gone. Way to thick for low rpm .070 dia wire

[Bruce S]

Chris;
 I don't want to rain on your parade, BUT...
In the video, he shows them turning even down to 2/mph, however he does not show or even mention the output of the PMA.
High-torque is good, IF your PMA is possibly a single phase unit and or needs to overcome cogging, BUT means very little when battery charging or trying to get them up to grid-tie voltages.
You could call them, and let them know you have them and in what wind speed you'd expect to see any battery level voltage output.
See more blades isn't necessarily a good thing, more blades on the old water pumpers works great! high-torque is needs, I saw about 5 of the old water pumpers just south of Iowa City, IA on highway 218, running nice in winds less than 3 mph, but all there were doing was pumping irrigation water.

Also , further down in the specs you'll see the blades aren't actually 59" in dia, as the hub is 11" itself so you only have 48" blades 

NOW I will say that you can certainly do some "stuff" to get this up and running, by doing a rewire. Go searching on here for Jerry, he did some stuff with these for low wind that can help you out.
Best of luck!
Bruce S

[chris]

OK so can anyone help me with winding up the stator. I guess if it's needed I can make up a new case and stator to make it work.  Any ideas.  I do have access to all plastics and a waterjet to cut out a new stator.and I can make a new case to fit the new stator. No limits here .thanks again for all your help.

[Watt]

OK so can anyone help me with winding up the stator. I guess if it's needed I can make up a new case and stator to make it work.  Any ideas.  I do have access to all plastics and a waterjet to cut out a new stator.and I can make a new case to fit the new stator. No limits here .thanks again for all your help.

Did you happen to spin up the alternator before you cut the wire out of the stator?  Also, Flux ( member or the board ), has mentioned before in posts regarding permanent magnets in stators and widths of each slot.  Also, Zubbly ( RIP ) also has some awesome write-up information regarding motor conversions which may be relative you your setup.  Good luck.

[chris]

And what about these guys, http://www.hydrogenappliances.com/powerpmas.html


How did they do it. Are they any good. And what about wind blue power.com And there 520 And 540 low wind pma's.

[chris]

I did run it. Up to 3000 rpm and I did not see anything better then. 03 volts dc. That was with No load.   the original had 14 poles on it....
 And how do I get to his stuff.

[Bruce S]

Chris;
 Both places have their stuff, and from what I've seen they don't really work as well as the advertisement  .
The spin up test, try doing it a gain, but put the meter into AC mode and see what you get.
To get to either one's write ups, use the search button that's just to the right (on Firefox) or better yet use the google search that show up at the bottom, while logged into this forum, you should get tons of hits.
These gents are some of the true, guru's of this 
What wind speed are you looking to go after? if you're in a high-wind are and want to go after the 10mph great, but if you're after the 3-5mph winds, you will find that there's little to be gained from this wind speed area.
Cheers;
Bruce S 

[chris]

Hey Bruce,  I did check the ac and there was nothing.. At all rpms . Just a lot of heat around the out side on the case.    I was stuck there so I thought that the winding did not match the position of the new magnetics on the stator. ... ? Is that possible.

  I'm looking to take advantage of the 10 to 15 mph I'm getting at my house.

[Tritium]

Your magnets are mounted N-S-N-S-N-S-N-S facing outwards aren't they?

Thurmond

[hiker]

heres one i did awhile back...9 and 12 setup..two 9s..18 coils total..3 phase-star
used some fine wire--50 winds per coil..lit up one 50 watt headlite at a fairly low speed on the hand drill--or 3 -50watt headlites wide open..i  may rewind it all with mag wire--this was just a test alt..
not sure what you can do with yours--6coils and 8 mags--you should be able to get  2 or 3 sets of 6 coils in there..3 phase..or wave wind it ?
looks like your mags are a bit oversize for that size of stator......

[Watt]

Hey Bruce,  I did check the ac and there was nothing.. At all rpms . Just a lot of heat around the out side on the case.  >:(  I was stuck there so I thought that the winding did not match the position of the new magnetics on the stator. ... ? Is that possible.

  I'm looking to take advantage of the 10 to 15 mph I'm getting at my house.

That is very likely.  Seems to me your magnets and coils do not line up properly.  I assume 12 coils in series and 36 total coils.  I also assume your magnets are alternating n and s poles on the rotor ( sorry about the double questions, There was a reply before I could finish the post )?  Does the stator core have 36 slots?  How wide are the slots, outside of one to the outside of the next slot?

[chris]

    :)Yes that is what it was. And they are n.s.n.s.n.....

[chris]

Yes there are 36 slots the start of the stator is 4.500 in dia,  and the slit's are. 125 wide.

[chris]

I don't have the empty stator here, but last week I did trace the stator after I cut out the old coils here at work.

[chris]

Hey thank you wild in Alaska.  Yeah I think it went a little overbord on the magnets for this one.  Lol that was $140.00 . Which I told the wife I can do this. i hope.. and thanks for your pictures. And ideas. Keep me posted on that.

[chris]

Hey Bruce if this helps. The old coils were wound 5 times. And The spread on the inside of the coils was 1.25 with my callapers. The wire diameter was  . 070 + inches ... when I get home I will measure it up and send new info if it's different.

[Bruce S]

Chris;
These guys have me beat with their extensive knowledge of building these.

Make sure you get back to them on their questions.
I saw the mags and kinda knew they were a little much .
If you still have the old empty unit available? grab it!
You can use it to rewire it.
One issue will be the number of magnets in there; with 8 you may have to go 2-phase to get away from the cogging you may see, even though there will still be some.
At what voltage range are you looking to work with?
Bruce S

[chris]

Well I have a 12 volt rectifier regulator. And I do have 16 n48 1 in long x 1/2 x 1/2 magnetized thru the 1/2 and 2 more rotor styles I can use. But I can cut out a new one for 14 poles like the original rotor had...and if I want to use this ever on charging or a grid tie with multiple of these inseries.what would you recommend.

[chris]

This is what I have now., these are 16 pole rotors, one is made out of aluminum. And one is made out of steel to tie all the magnets together for a stronger field .  Plus the 8 magnetic big daddy... what would you recommend for a new rotor design to be able to hold a 3 phase inside the stator, i have access to a water jet so I can cut out any style. And thanks Bruce.. I've been lost in this for 3 weeks, and now I'm finely talking to someone who can help me.

[chris]

Your magnets are mounted N-S-N-S-N-S-N-S facing outwards aren't they?

Thurmond

Yes they are.

[chris]

The aluminum rotor is welded and has a fan style center to help keep it cooler.

[chris]

Do u think that i should use the steel to magnify the polarity of the magnets.

[Watt]

Do u think that i should use the steel to magnify the polarity of the magnets.

I would think a steel core rotor, which would be flats on the inner most part of the magnets, with an aluminum retainer/separator would be ideal.

I see your measurements there but I am wondering what the measurement is from the L outer edge to the adjacent slot L is.



    Up against the lower (-->_l  l_  _l  l_<--) to the lower notch ( measurement in between the brackets and arrows ) if this make since.
    You might also do the next over as well. _l  l_  _l  l_  _l  l_   

[CraigM]

Hello Chris,

Let's see if I can shed a little light on this starting with your stator/rotor geometry. Since you have the tools to alter your rotor we'll start with the fixed number of slots in your stator. With a 36 slot stator there are a couple of options that come to mind for the number of coils you need.


This is a 3 phase, 18 coil, 6 coil per phase, overlapping coil design with the three phases shown as red, green and blue. Notice how 6 of the 12 magnets are in line with the green phase at this point. With 36 slots you will need 12 poles (magnets) and will not be able to use the 8 pole design you have because the geometry is incorrect for 18 coils. When you alter poles N-S-N you'll also see that all coils of a particular phase are seeing either all N or all S poles at the same time.


This is a 3 phase, 9 coil, 3 coil per phase, non-overlapping coil design with the three phases shown as red, green and blue. Notice how 3 of the 12 magnets are in line with the green phase at this point. This is the design that Hiker used in an early part of this thread.

Do u think that i should use the steel to magnify the polarity of the magnets.

It appears your rotor is made from aluminum. What you need to accomplish is a closed loop for the magnet flux to travel. The flux from a north pole will travel towards the stator steel, through the steel to the adjacent south pole, exit the stator down through the magnet, exit the north pole into the rotor and emerge in the adjacent south pole. With your aluminum rotor design you're not giving the flux a path to travel in the rotor. Change the rotor to magnetic steel or add a steel ring to the rotor and you'll have a closed magnetic circuit.

Hope this helps you visualize what's needed.

CM

[chris]

Thanks u guys, that does help, do I want to grind the magnets to  the original diameter or can I leave them with a flat.and what size wire and how many turns, and how big can/do I make the coils. How long should each coil by to get the resistance to get the correct amps and volts.

[CraigM]

Thanks u guys, that does help, do I want to grind the magnets to  the original diameter or can I leave them with a flat.and what size wire and how many turns, and how big can/do I make the coils. How long should each coil by to get the resistance to get the correct amps and volts.

Chris, I've spent many months reading and researching the wealth of knowledge contained in this forum but I'm still a newbie and feel others are better qualified to answer your questions.

However, I can offer a few pointers to help you along the way.

• Read, read some more and then go back and read it again... it will sink in.
• Neo magnets corrode easily, do not grind and remove the nickle plating.
• Search "test coil", "wire size", "wire turns", "geometry" and everything else you can think of... you will learn from this.

Keep up the passion and enthusiasm, looks like you have some great machinist skills and could build just about anything.

CM

[chris]

Hey cm thanks.  And here are those other numbers u wanted, I think.

[chris]

Also what should I make the air gap to. From the highest point of the magnets to the 4.5 Inner dia  of the stator. For a low cogging pma.


And will the distance between the rotor o.d And the air gap of the stator affect the magnetic field. The rotor core is now steel h.r.s 1045 it's going to be the same design of the aluminum. One with the internal fan. The distance right now is. 250 (1/4) inch.per side.

 P.s. this is An older design for 16 magnets, the new one will be for 12 like We talked about.