Step 3: Rotor and Stator

One of the more technically challenging and labor intensive parts of building a wind turbine is winding and casting a stator coil. A very thorough knowledge of permanent magnet generators is needed to calculate how to wind an optimal stator. If you are determined to do it, you can simply follow the example of someone else's successful generator. Again, this being my first shot at windpower, I didn't want to risk winding the wrong thing, messing up the wiring, or ruining the casting, so I bought one from Otherpower.com. They make lots of different stators for a variety of magnets (rectangular and round) and voltages. Most axial flux wind turbines use a three phase stator for more efficient generation.

Since this is a single rotor design (stators on Otherpower are usually made for dual rotors) we will only be generating half the stated voltage. So, for this project I wanted 12 volts and had to buy a 24 volt stator. Otherpower actually is now offering a kit for a single rotor wind turbine that is pretty much the same as this one. It's still cheaper to fabricate your own, though.

The stator is made for a 12 inch rotor, but the Volvo brake rotor is only 10 inches. So, we were forced to add on to the outside edge. This was probably not the best solution, but it should work fine. I would recommend getting a 12 inch steel disk from a CNC water jet if possible, which would be a lot cleaner and provide a better surface to mount blades.

We used a piece of 1/2 inch plywood mounted to the strut and then mounted the stator to the plywood. Make sure there is clearance for the stator coil to clear the wheel bearing.
<p>A friend and I built a wind turbine but now the friendship seems to be &quot;gone with the wind&quot; and the turbine is just standing next to my house but it is not turning (yet) as it isn't &quot;switched on&quot; because the rest of the system is not ready for the WT. My friend was the electrical wizard and I did what was NOT electrical. Is there a way we can briefly communicate about several aspects of the turbine a.o. ...I have seen it all been made but I didn't take notice of things like the number of windings of coils, connecting to existing solar system &amp; the dump load etc ?</p>
Hi Albert,<br><br>This is a very old account of mine that I haven't looked at much in quite a while but I got your message and was interested to learn more. It looks like you have a nice little machine there of a similar Hugh Piggot style design. What are you planning to do with the turbine? Are you off-grid or grid-tied? Do you know what kind of controller you'll be using to regulate the turbine or will you be directly tied to the batteries with a rectifier? <br><br>I can't promise I'll be immediately responsive as I'm fairly busy but I still work with wind turbines (although they're a bit more complex now see: http://www.pika-energy.com/). I haven't done much with these style turbines in a while but I should be able to point you in the right direction. It'd be a shame for all that work to go to waste!
I found out that is was a 1.4mm copper wire.<br><br>
Thank you for your quick response.<br><br>I am off the grid completely since Sept 2012.<br>I started with a 12V system but in November last year I changed to 24V to accommodate the turbine. I had far too many solar panels (the shops sell you anything) and also the OutBack MPPT can't handle the turbine.<br>I recently purchased a Morningstar TS-60 (which has a rectifier) but it is still in the box because I have to make a dumpload for excess power generated by the turbine.<br><br>You don't have to sacrifice any of your time to help me but assistance would be appreciated.<br>
<p>Sure, a TS-60 should work for this setup once you get a dumpload setup. How large is the turbine? 10Ft diameter? Did your friend make the alternator for a 24V system or 12V? If you knew what gauge wire and how many turns were used we could probably figure out what it is. </p>
<p>A photograph showing the size of the turbines blades.<br></p>
Ooooooh, let's get a few things straight. <br>:-)<br>I was under the impression that &quot;my friend-who-turned-sour&quot; had developed the turbine from scratch. Seems he was more internet-literate than I am and had it all copied from manuals available on the internet! <br>Now that you mentioned the name Hugh Piggot, I was able to download some of those manuals myself.<br>I still have to find out what is it that is standing here on my property.<br>There are 8 coil stators, 15 coil stators...........<br>I do know I have a 9 coil stator.<br>I need to know more of what is inside my turbine.....
The turbine is made for 24V (I have heard him mention that it goes up to 29V) . <br>We don't work with &quot;feet&quot; but I think it is a 10 ft diameter.Let me get a pic from him and the blades.<br>The gauge of the wire: I made the payment to the supplier of the wire from my business bank account and could request a specified invoice for &quot;Tax Purposes&quot;. I will try to do that tomorrow as by now it is already 20h00 local time here.<br>I know that the coils were wired &quot;double&quot; as you can see in one of the pics with all the red insulation tape. The wire of the big roll of wire was &quot;split&quot; in two rolls from which he rolled the coils. I don't know why it was wired that way and that is what I would like to know. He also mentioned that he'd wire it with a few more extra &quot;rotations&quot;.<br>Thanks for your willingness to assist.<br>Are you anywhere near the &quot;Blizzard of 2015&quot;.<br>We have a wonderful summer at the moment. Oh, I hate winter and would prefer the 30'C and more every day of the year.<br>Rgds<br>Albert
<p>Very nice setup and instructable. One question: how did you connect the generator to the base? The generator is on a spinning platform so how do you avoid the cables twisting when the wind eventually makes it rotate many times (random movement means the angle will go roughly like t^(1/2), slowly but eventually getting to a point where you need to unwind the cables...</p>
<p>Good question, that's pretty interesting actually. As you can imagine, many small wind turbines run into the same issue you've just described. Surprisingly it is fairly rare for a turbine to make a complete 360 rotation, although it does happen. Some people use SO wire to run the length of the tower and install a connector in a junction box at the bottom of the tower. Every 6-8 months or so they disconnect the turbine and untwist the cable. My build would have to do something like this. Other turbines use slip rings and brushes (like in an electric motor) that allow the turbine to rotate 360 degrees without tangling the wiring. I haven't seen many DIY slip ring builds though, that would be pretty interesting to see on a low voltage system like this. </p>
<p>Thanks for the reply. Yes, it will likely take a long time for the cable twist to be a problem. I like the idea of simply checking every few months, unplugging, untwisting and reconnecting. If you ever implement it I'd be curious to know how random the rotation is. I presume that with the very asymmetric configuration you have it may preferentially rotate one way (which would be more serious than a random rotation). Keep us posted and keep the electrons movin'!</p>
G, DAY MATE<br><br>THAT IS FANTASTIC A JOB WELL DONE.<br><br>UM I PROB MISSED TI BUT HOW MUCH POWER DOES YOUR BABY PUT OUT.<br><br>I WAS GOING TO MAKE THE oops sory about the caps.<br>1000w turbine that is also on instructable but now im gunna make yours.<br><br>i dont have the space to place it so high in the air but im sure ill find a way to secure it to the top of our roof securely and safely<br><br>cheers bud <br>
i met half of the volts
i want it to make the same wind turbine project,but i have a question ? if want it a 12v stator you said you had to purchase a 24v stator but in the pitcher it shows a 12v stator . i want it to know if a single 12 magnet rotor with a 12 v stator then it will only produce in low winds half of the watts. is that the reason you had to use a 24v.
ive made a 9 coil 12 magnet stator an axel with the wind at 15 miles what will it produce i thought it was an AC output to a refractor so does it hook into the inverter from there an what kind of inverter do i need my refractor is an 80 amp is that right thing to use<br><br>
Hey im loving this instructable, the wind turbine at my college got me interested in building my own. I thought this looked very do-able until i got to this step. I was wondering how much the controller and other parts in this step costed, and if it was difficult to assemble them all?
I can't remember exactly what I paid for them. I think it was in the range of $120 each. I bought two, but only ended up using one as the charge controller. I used a bridge rectifier and a schottky diode to rectify the three phase power coming off the turbine. The controllers weren't hard to hookup the manual that comes with them is pretty good. There isn't any assembly required, just wiring the wind turbine up. I think I had to change the position of a jumper and that's about it, there are small potentiometers to change when the dump load is turned on (by checking the battery voltage). <br><br>I've really gotta update this thing though. Currently the turbine is down for repairs, a weak spot just above the weld on the tail's hinge pin gave out. I plan on redoing it almost entirely at some point but college has been keeping me busy. <br><br>If you've got any more questions, feel free to ask. One thing I can definitely say though is if you don't want to be constantly maintaining the machine make sure you don't cut corners. Do it right, or do it twice.... sometimes you gotta learn the hard way, eh? Best of luck.
So wait, do you spin the magnets or the wire coil?
You spin the magnets. That makes it easier to connect to the coils, since they are stationary.
Excellent instructable! I'm thinking of building one of these for my home build project. But I was wondering, it would seem possible one could use the core technology (i.e. the magnet and coil assembly) and arrange for other ways to make it spin and generate electricity, no?&nbsp; I was thinking, could I build that part and say use water power to spin it and make it generate electricity? Or find some other creative way to spin it.&nbsp; :)&nbsp; Thanks.<br />
&nbsp;Sure, people build homebrew permanent magnet generators all the time for various applications. Wind, hydro, steam, human power, whatever. Just make sure when you wind the coils to get the right gauge wire and the correct number of turns. This can take a bit of experimenting sometimes, but you can also reference a lot of material online.&nbsp;<br /> <br /> Be sure to show us what you end up building, good luck!<br />
That's great to know! Thanks. :) I'll be sure to document it and let you know. I will most likely work on something like this alone and don't think I'd be able to handle the pole creation and standing part alone but I could use this same technology for ground level electricity generation. <br />
va....v very nice please send deatails images and drawing for genereter rating details i m starting a new wind turbine 1 kw manufacturing by home made . then so pls help <br />
&nbsp;If you would really like more details plans for the generator I would suggest visiting Hugh Piggot's website and purchasing his book &quot;A wind turbine recipe book&quot;. It's full of detailed plans and specs.&nbsp;<br /> &nbsp;<a href="http://www.scoraigwind.com/books/books.htm" rel="nofollow">www.scoraigwind.com/books/books.htm<br /> </a><br /> If you've got any specific questions I can do my best to answer them, if not the guys at www.fieldlines.com can probably help fill in any gaps.&nbsp;<br /> <br />
thanks , for u r sugess but we wont to 1kw genereter making the basicaliy rating of genereter&nbsp; and&nbsp; iwas perchasing this wec book but there not specifiy ingenereter rating ditails and wave deatials . i thk u r sugess me&nbsp; .genereter details . india&nbsp; here ueing the matric system . but book in site all dimanstion mph inch etc there&nbsp; .<br />
&nbsp;There are both metric and standard (english units) versions of the book available on that site.&nbsp;<br /> <br /> I think you want a more in depth analysis of the generator. Most homebrew wind power folks won't get that in depth. Basically Hugh's book would outline which generator plans seem to work best partly through trial and error.&nbsp;<br /> <br /> I think to get the kind of detail you want, you might consider a different book with more mathematics. However that book might also depend on if you are making an axial flux or radial flux generator.&nbsp;<br /> <br />
tx brokengun,<br /> <br /> &nbsp;<br /> &nbsp; i have agree with u u r coment&nbsp; i have making&nbsp; for axial flux genereter. but i don't know&nbsp; which parameter using for generotor making,&nbsp;&nbsp; only 30 mtr tower bearing ,gue rope , tail van avalable&nbsp; here&nbsp; but&nbsp; genertor details not avalable <br />
&nbsp;I guess I am confused as to what parameter you want. The book I recommended specifies wire size, number of turns and the physical dimensions of the coils and the casting. Basically everything is there. There is more information not included such as how much power that stator can handle but this can be roughly calculated depending on the resin used.&nbsp;<br /> <br /> The wiring of the coils is basically a matter of your application and preference (eg. star, wye, delta).&nbsp;
how much price sir , book parchasing ,im not parchasised book <br />
Great job man bright future ahead.
You can buy a 400 watt wind turbine for about&nbsp; $600.00 from the Sportsman's Guide,of course youve got to build or buy a tower,Theirs is 30' and about the same cost&nbsp;is about the same cost.
&nbsp;The one in the Sportsman's Guide looks like an Air-X brand generator, although it doesn't say the brand on their site. The rotor diameter of that turbine is slightly smaller than mine. Also, I have heard a lot of complaints about the noise generated by the turbine's blades.&nbsp;<br /> <br /> Other than that I don't know much about that turbine in particular. I've seen a few around. It looks like there tower setup costs $650 as well as the generator. Don't forget the controls, wire, batteries, concrete, etc you might need.&nbsp;<br /> <br /> I will say it is definitely less work!&nbsp;<br />
Yea,I just figured Id through that out there,the tower they sell in my opinion is kinda over priced.Also I was going to make my own useing a RV generator,and use the old control panel and stuff out of the RV Im scrapping what would be your thoughts on that?
Do you mean the alternator that is hooked up to the RV's engine or a separate generator that produces electricity for the RV?<br /> <br /> Car alternators charge at a very high RPM, much higher than most wind turbines so reaching charging RPM can be difficult or require gearing of some kind.&nbsp;<br /> <br /> Many people rewind the stator coils in an alternator with thinner wires to achieve higher voltages at lower RPM. It's a project and there is some figuring involved depending on the dimensions of the alternator and what power output you want from the thing.&nbsp;<br />
Yes,They call them altenators now,but this is an old RV and its actually a generator,I was going to do a small diam. pully at the blades and run a belt&nbsp;to get some higher RPMs at the generator&nbsp;,and use the old breaker box,charge control and other stuff less the wire and recepticles.I figured Id run it to three deep cycle batteries,I just want to try something that will take care of my bedroom,computer,small lamp,ex. for when we lose power,sorry for the bad spelling by the way.
its a good and clean build but is this wind mill too heavy? i was thinking of making it out of fiber glass and really light weight stuff for the wind turbine.
The machine is quite heavy, yes. However part of this is out of necessity. The rotor which is made of steel should be made from some ferrous material. A ferrous material is helpful for the efficiency of this alternator. I think it has to do with improving flux and essentially turning the entire rotor into a big magnet. However the back pieces could be made some something else I guess. There is a lot of stress on those part though. The bearing and nacelle put up with a lot of bad weather and harsh wind so I would rather have something with some heft. The other place to save weight would be with the tail. As far as that goes, I don't think you would save much weight compared with what I did. The electrical tubing used was very lightweight and the 1/8 inch stainless steel that the vane was cut out of is also pretty light. If you do end up making some of the pieces shown here out of fiberglass, I would like to hear how they hold up.
love the tower install great job
Basically yeah... we had to expand on the 10 inch rotor to make it fit the stator coil that I ordered. However if you're good you can wind your own stator to fit a 10 inch diameter brake rotor. I'm sure a lot of different brake rotors have been successfully (or could be successfully) used like this.
Is that a weedeater with a saw blade on it!? (in the background)
Yeah basically. It's for clearing woody plants and stuff. We live in the woods.
That looks really professional...
would any old brake rotor work for this?
great project I think it is a good Instructable and if you can send me the schematic and firmware for the controller with the lcd it looks very cool to make for projects like this one
I didn't end up completing much of the controller at all. Really all I had was a voltage divider circuit to read 0-12 volts and a temperature sensor that worked on the LCD. I tried to find what little code I did have but I just moved to a new computer and apparently the old stuff is nowhere to be found. If I do locate it I'll send it though. <br/><br/>I used this LCD: <a rel="nofollow" href="http://moderndevice.com/LCD.shtml">http://moderndevice.com/LCD.shtml</a> I would recommend it. I wouldn't recommend their arduinos.... I bought two and couldn't get either of them to work, maybe it's just me. <br/>
that's OK but thanks though
Great instructable. Gotta love the name too.
Thanks for the info on your wind turbine and the list of books you got a lot of your info from. On most of the wind turbine "how to" no one gets to the part of the type of wires to run from the wind turbine to the batteries. I heard the wires and batteries is what cost the most. How far is your wind turbine from your house, and where are you setting up your batteries? Great job on you project and getting it set up!!
I don't think the wires cost the most but then again I guess that depends on how far you want to run it. I used 3 conductor 6 gauge copper wire, which is pretty expensive stuff... Looking around online it looks like it's in excess of $1 per foot (probably much more for 3 conductor). I lucked out and got mine for free, there were lots of freebies in this project. I also only had to run it down the length of the tower to the box where the battery is. Keep in mine though, that my generator is a 12 volt one and thus requires thicker wires for lower resistance. Most people who would be doing a DIY wind turbine to supplement their house use a higher voltage which requires thinner wire. This is overall a good idea and I would recommend it as it will definitely save you money. Where the money really comes in is the tower, it's hard to get a good, solid tower solution for a good price. A lot of people tend to forget how expensive it may be.

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