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Author Topic: I am building a Magneto, need help with the coils...  (Read 12925 times)

twilightinsanity

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I am building a Magneto, need help with the coils...
« on: March 20, 2007, 01:08:15 AM »
   I have built a contraption that turns at about 50 Rpm's and can lift 35 or so Lbs (lift measurement was done with a cord tied to a weight and then tied to the rotating 1 inch shaft that sticks out of the side of my contraption)
   I know I'm gonna get flak for calling it a contraption, but I like the word a lot!
   Basically, my contraption is a waterwheel (for the sake of discussion...)

   I want to use it to generate eletricity. I think my best option is to buy some magnets and wire and make my own magneto generator. I know this is a very tedious job, but I have the time and patience (frankly I can't stop thinking about it and if I dont build it I will go crazy!) and magnetos are pretty simple.

   (Tangent - I just joined and my computer is making sounds like a kookoo clock... is this normal? It's entertaining, but not every hour... end tangent...)

   I am having trouble determining what kind of coils to make. Should they be cored? If I use the new idea of river magnetite instead of iron core will it help at all? (that is supposed to remove almost all back EMF)  How much resistance will a staggered magneto make once it has reached speed? How much current can I get if I set the whole thing up to make 60Hz AC 110 ? I can do this with the right number of magnets and the right Rpm's, but it's useless if I can't make any real amps...

   That's where I'm at... any advice would be great, I need a little direction here...

  Oh yeah, and It's nice to meet you all! Open minds are a rare thing apparently, it's good to see a place where they can meet, and grow ideas...

fleebell

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Re: I am building a Magneto, need help with the coils...
« Reply #1 on: March 20, 2007, 02:01:34 AM »
http://tech.groups.yahoo.com/group/awea-wind-home/

check out those guys, There is a complete set of plans on how to build an axial alternator.  You are going to have to gear up as 50 rpm is about 1/10 of the speed you will need for the average one. It's also a simple design , a 10 year old kid could build one following the directions given.

An alternative to that would be one of these types. These are also very simple to build.  You would have to build a big one to get  more than just a couple of amps  but your wheel could turn a really big one easily.  This type doesn't have anywhere drag as a standard alt does.  Lenz forces don't really have much effect due to the way it works

http://www.leebell.net/workshop/bobble.htm

The problem with big water wheels is they really don't put out much force as most people think so don't expect a whole lot of power from the one you have. From your description you only have about 250 watts worth of power or about .3 hp to work with. Don't expect to get more than about 100 watts max after friction losses.(gearing, efficiency of alt etc.....)  They work much better doing physical work than turning a generator.

 

twilightinsanity

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Re: I am building a Magneto, need help with the coils...
« Reply #2 on: March 20, 2007, 07:00:21 AM »
Yes, youre right, I calculated .46 Hp and a lifting force on a 1' axel of about 45+ Lbs using a thin cord. Thats probably not truly accurate in either case, but it's close enough, I'd say +/- 10% at most.

   OK, since voltage can be controlled with transformers, and phase can be controlled in at least one or two ways, (any ideas on making high freq. AC into lower freq.?) and more magnets and coils on a larger diameter wheel (I can do like a 14 foot wheel if I need to) means more current...

   I really need to know what kind of resistance to turning I'm gonna get from a Magneto! If I have a larger wheel, and more magnets and coils, they would pass each other faster due to the whole radial thing, then I would get more out right? But only to the point my wheel stops turning, which is at about 50 Lbs. at 35 or 40 Lbs however, it spins just right, at 45+ rpm's.

   I can make up to about 300 Lbs of torque, but I will never get above about 60-70 Rpm's even without a load. I can build a UFO sized magneto in my backyard if I need to. (The neighbors will think I'm completely nuts, but They probably do already, so why not, I say! Heh... ;)

   Is there a formula somewhere that describes how to calculate amps and volts with the number of windings in a coil and the speed of a magnet passing them or something like that?

I heard this saying once "Horsepower ruins tires, and Torque wins races" I dunno if it's true, but if it is maybe there is a way to convert torque into electricity - which is my real goal I guess. Any suggestions?

fleebell

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Re: I am building a Magneto, need help with the coils...
« Reply #3 on: March 20, 2007, 10:33:02 AM »
   Is there a formula somewhere that describes how to calculate amps and volts with the number of windings in a coil and the speed of a magnet passing them or something like that?

I've been looking for one for a while for something like that, If you find please let me know!

  It would be a lot simpler and much more convenient to run the output from the alternator to a charge controller to charge a battery and then use a inverter to get your  power back out of it. That way you don't have to worry about trying to control the speed of the wheel exactly and batteries are perfectly happy with the power once the wild ac from the alt is converted to dc..  The pulsing waveforms work just fine for charging.  I personally think they work better but thats just my opinion.  You can also use the power when you want that way and not just when the wheel is running.

  There is really not a lot of point in making a really big diameter axial type alt unless you just happen to like winding coils.  Unless you use many small coils and magnets your output wave forms are going to be just single pulses anyway.   It would cost much more to build than just using a "standard" windcharger type axial alt. One 4/1 and one 3/1 pully sets  to speed it up with your 50 rpm input that would give you  600 rpm and that would be plenty! 

This link below has a bunch of different examples and most tell you enough info to build them and what they put out.  It's not too hard to guestimate what you are looking for in coil size magnets etc.. just by comparing the different ones. Pick one that puts out about 30-40 amps into a 12v battery at 600 rpm speed and you should be right in the ballpark as a match.

http://www.otherpower.com/otherpower_experiments.html
 

twilightinsanity

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Re: I am building a Magneto, need help with the coils...
« Reply #4 on: March 21, 2007, 04:26:36 AM »
   Thanks for the links. They were really helpfull.

   With info from the various places ive gone while researching this, ive learned some useful stuff. Mainly, in respect to my problem Ive learned that RPM's are only half of the equation, the other half is wheel size (size matters after all). If the wheel is bigger around, the edges of it are moving faster, and so the magnets pass the coils faster and make more electron movement. Yay! Of course that has some drawbacks too, like increased weight, bearing drag, magnet cost, and plus most people dont want a giant metal disk in thier yard that spins around. Might as well wear a foil hat.

   Man Im full of jokes today... Heh - maybe later one will be funny.

   
   Anyway, I have a .5 Hp drill, and I lost the chuck so I have to put it in reverse to get the bit out and in (you know the deal...)  Well, it isnt too hard to stop that drill from turning with my bare hands (I'm no popeye, my hands are used to typing, not stopping things from turning) All I'm saying is if that .5Hp drill is so easy to stop from turning, then why is my .5 Hp wheel so hard to stop (It's impossible to stop it by holding on to the shaft, you have to really grab the edge and make faces and stuff.)

   So I have more torque than a windmill (20 ft) (I think) and the 20 inch dual rotor magneto on the windmill I saw made 3Kw (3000 watts right?) at 65 Rpm and cogged badly above 200. If I doubled the 20 inch diameter magneto to 40 inches around, and even keeping the origonal 20 magnets I'd get 3kw from 37 Rpm's of my wheel. Right? Then adding 20 more magnets and a proportionate number of coils would give 6Kw right? Double it all again (with a second row of magnets and coils) and it would be 12Kw Maybe 10, maybe more, but nonetheless a fair use of high torque and low Rpm's.

   I'm still wondering how the load resistance thing works, there must be a formula someplace. If the resistance to turning goes up with the amount of force being used by the load, or if the resistance to turning goes up in relation to speed or what...


fleebell

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Re: I am building a Magneto, need help with the coils...
« Reply #5 on: March 21, 2007, 05:52:52 AM »
Well, first of all if you can stop a .5 hp drill with your hand either you are built like an ox or your drill is having some serious electrical problems,  Because you really shouldn't be able to do that.  with a .25 hp maybe but not a .5 hp.  Also you need to remember that your are stopping a small amount of mass in a drill but that wheel is a totally different story, There is a lot of mass there you have to stop and it's not quite the same thing.

Yes you have it more of less correct with the magnets and coils but there is no way your are going to get out more than the wheel can put out.  I mean if you only have 1 hp input your not even going to get one hp output. Simply can't be done. They are getting some unusual effects with electrical stuff but your not going to beat the laws of physics with a simple mechanical device like a wheel.   Simple friction loses would do it.  Otherwise everyone on here would be running water wheels and be happy campers because they all had a perpetual motion machine and could quit wasting their time with all the odd things they trying out now . 
 What you are going to end up having to do is use a lot of small magnets and coils instead of just a dozen of so big ones that would work with the smaller alternator diameter.  You are not going to get away from the lenz forces just by using a bigger wheel. they just get spread out but they are still there.  Your right in that you will get the speed on the outside diameter with a lower rotation but thats as far as that goes.
 All the rest of the normal effects will still apply. 

Lee



twilightinsanity

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Re: I am building a Magneto, need help with the coils...
« Reply #6 on: March 21, 2007, 10:20:10 PM »
   OK man, (please note - I call everybody "man"  so do not take it in a sarcastic sense, it's more of a 70's hippy term, and not derogatory - just so you know...)

   So anyway, I'l admit to being a big manly guy, 6'5" 280 with hands like frisbees, and maybe thats why I can stop my drill. I have three drills, one .5 and two .25 models, the two smaler ones are easier to stop, so I assume that unless all of my drills are equally broken, my previous statement was true. I'm hooked up to the grid, btw, so it's not a weaker drill because of my supply. What can I say, I got muscles...

   I am reasonably familiar with the whole free energy scene. I have some ideas along those lines as well, but they are unformed ideas, and are most certainly not anything I am trying to incorporate into this particular idea. I am looking for a free lunch, granted, I'm just not looking for it in ways that conventional physics disagrees with. I truly believe that conventional physics reaches a point where it fails to describe accurately the actions of certain energies, and in fact fails in a lot of ways here and there, escpecially in chemistry, metallurgy, and in transitional energy forms.

   I also understand the losses which are incurred at every stage of any circuit. This includes the losses in the bearings, gears, and even wind drag, as well as electron resistance.
   I also know that you can't get out more than you put in (not in a mechanical system anyway, and I consider the whole thing mechanical, because a magneto is basically an electron pump, and can be considered mathematically just like a water pump or an air pump - mostly. Enough to consider it as mechanical anyway.)

   So let me use the mechanical analogy for a minute...

   We have a small bucket full of mass (water or sand or whatever kind of mass is your favorite) We have a wheel that is turning at a constant rpm and with a constant force. It can lift one small bucket per minute. BUT!  The wheel turns with so much force, that it is capable of lifting a larger bucket full of twice as much mass in the same amount of time. The larger bucket increases stress on the variables in the system, like the bearings, but this dose'nt matter because we are still getting twice as much work done in the same amount of time with the same machine.
   If my contraption is the wheel, and the magnets and coils are the buckets, then my question is how much mass can I get in my buckets before it stops my wheel.
   The answer so far has been between 375 watts (using a formula from a waterwheel site that you directed me to) and over 3 kilowatts (going by the results of an equivalent windmill, from another site you sent me to)
   Obviously I like the windmill numbers better, and I find the information on the windmill to be perfectly credible. I also thought the waterwheel site had credible info as well, so why are these two sets of numbers 1000%  different? I think it has something to do with the construction of the devices in question, and for what purpose they are used.
   I'm not disagreeing with Lenz, or Maxwell, or Newton, or You, or anybody else (except maybe the waterwheel site, due to preference), I am simply saying that if a windmill can make 3000+ watts, with 20 magnets and 15 coils at 65 Rpm, then with twice the wheel and twice the magnets and coils I should be able to make twice the watts with half the Rpm's. That comes out to 6000+ watts, assuming the resistance of the coils does not slow the wheel to below 35 Rpm's. That is correct I believe...  Right?

  Side note - Whats up? When I am on this page, logged in or not, I get KooKoo Clock audio, it is freaking me out! Does this happen because my computer is insane, or is there a checkbox someplace, or what? It's weird.

   Anyway, If I can phase it correctly I can end up with enough constant wattage to power my house, without the need for batteries or inverters. What would happen if I tried to run say a refridgerator, on 65 Hz AC, or 55 Hz ?

fleebell

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Re: I am building a Magneto, need help with the coils...
« Reply #7 on: March 22, 2007, 01:01:46 AM »
 Well , that explains the drill :D   The average sized guy cannot do that with a .5 hp.

  Anyway, you are correct on increasing the magnets and coils as far as I can see but what you are misunderstanding is the torque required.  Any windmill that's only turning that slow and still putting out 3 kw would have to be a BIG one. 4-6 hp at the wind speed it is doing it at. 
 
I'm attaching a page of charts I have collected from all over the place that cross references some of the different info.. maybe this will explain better than I can can about the hp differences

That clock is in the sidebar on the right at the top, you can click on it and turn it off

  Build and try it, the worst thing that could happen is you only get the 3-400 watts output and you might do better. It all depends on what your torque output really equates to.   You can always build more of them if it doesn't put out as much as you want till you get enough of them that will.   Thats what I'm slowing doing, building small setups that will eventually add up together to provide the output that I want.   
« Last Edit: March 22, 2007, 01:42:43 AM by fleebell »

twilightinsanity

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Re: I am building a Magneto, need help with the coils...
« Reply #8 on: March 22, 2007, 09:10:29 PM »
   Thanks for pointing out the KooKoo clock - I thought I was losing it! Funny thing is, my active X controls are kinda messed up so I can't turn it off anyway! O well...

  That windmill I got my numbers from was pretty big - 22 feet, 3 - 10 ft blades and a 2 foot Gen. You know, I wonder why they dont put more blades on windmills. It seems like it would just be a good idea...  Regardless it was a giant windmill. It can be found through the links you placed in your first few posts, it's on the bottom of a page of windmills, apparently the culmination of 6 years practice by the builder.

   Those charts you posted are indeed helpfull. Thanks again.
   I'm thinking you are right about just building one and seeing what it does. That is the next step anyway, and I was thinking about making the whole thing kinda modular so that I can add more torque layers or generator layers as needed. The flat circular form of an axial magneto just begs for a modular design due to the magnet orientation.

   So, with the decision to just build one quick comes back the origonal problem...

   What kind of coils should I use? I mean, I have an idea, and some formal electronical skooling  :D  but its been nearly ten years since I've actually built a coil... Basically I guess it will depend on the magnets and the speed at which they pass the coils, and the desired type of output, and several other things including if I hold my mouth right while im winding them... :-\

   First consideration is whether or not there is a low drag way to do this. I think you sent me a link about something like a low drag generator, and most likely the only way to build one is to build something from a free energy site, which is fine with me in most cases. If it works - it works. However, I don't wanna break from the origonal idea and get into something that is miraculous but might not work either...

   Second consideration is whether or not to use a core in my coils, and what kind of core that should be if applicable. I saw a Tom Valone video where he described the magnetic properties of a black "river magnetite" mineral, that is a very common and useless byproduct of metal mining. Apparently there are huge piles of it dug out while mining, and it is simply discarded like any other waste dirt. Supposedly it has no back emf feild, as it completely demagnetises instantly when the power is cut from the coil. This is a pulse motor application though, and I don't know if it would benefit a Magneto...?
   I have seen mostly air core coils used, but I have also seen copper and ferrous alloys (like coat hangers) used as cores. I don't know what to think about it all...

   I'm beginning to semi-seriously consider a high efficiency generator instead of a Magneto, but I'm afraid the rpm's would kill me.

fleebell

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Re: I am building a Magneto, need help with the coils...
« Reply #9 on: March 23, 2007, 01:29:07 AM »
Now you are getting into the headache section.  The number and size of your coils will depend mainly on the diameter of your wheel and the size of the magnets you intend to use.  It also depends on how close you can get the magnets to the coils. You want less than 1/4" (even closer if possible).  Just guestimating here as I don't know the diameter your working with but I would suggest using about #16 gage wire and try about 20-25 turns as a test coil if you are going to be using more than about 12-16 coils an magnets.  This also depends on what way it's going to be wired. Star,delta,single rectified, etc.....  That should work pretty well for a large diameter wheel but be prepared to experiment some. (will probably need more turns but that's a good starting number for a large diameter wheel)

   You will either need a metal backing behind the coils or use the black sand. I have tried both and prefer the metal sheet behind the coils but I haven't tried anything the size your working on so it might be easier for you to go with the sand in the center of them as it would take a very heavy piece of metal (plain sheet metal is not thick enough to contain the field  unless you use at least 3-4 pieces together).  The sand is pretty easy to get. just tie a strong magnet to a string and drag it in the dirt beside  just about any asphalt or gravel paved road.  I collected over a cups worth just dragging one back and forth in the sand beside the road in front of my house in about 1/2 an hour.
 Just mix it up with epoxy etc to fill the center of the coils.  I would wait though until you get a coil size figured out and then make 1 coil with the sand in the middle for testing as the sand should  increase  the output once it's in the coils and you won't be able to change them after the sand is glued into the centers.  Get one right first and then the rest will be easy.

The other link I sent you was to my bobble generators.  They don't have much in the way of lenz force feedback because of the way they work.  But it will take more coils doing it that way as the individual coils on the bobble gen don't/can't  put out as much as a regular built gen's coils do.  The good part though is you can add them to the wheel as you get them made, they don't all have to be there from the first unlike a regular generator design does nor do they have to have a tight clearance as they actually need about  3/4" space between the rotor magnets and the coils to operate properly.
  It might actually be easier to use them because of that. The wheel won't have to so perfectly flat on the sides running with them. Just use more and use round magnets inside the coils or the noise of the magnets inside the coils forms will rapidly become annoying. (the original bobble gens used flat round magnets inside the coils and was very noisy when operating... I've gone to sphere shaped ones now and they are much quieter- can't hardly hear those at all.

Good luck with your project, I'm just getting started on a new project idea of my own.
 a solar hot water powered generator system. - I'm calling it "the micro-tide generator"

Lee




twilightinsanity

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Re: I am building a Magneto, need help with the coils...
« Reply #10 on: March 23, 2007, 07:29:47 PM »
   I am thinking about probably using 2 inch cylindrical coils with a 1 inch core and I'm not sure how high to make these coils (length of cylinder) because I don't know how far the magnetic feild extends from the magnets since I dont have them yet. I have seen a few places that sell them, and 1 inch by 1/4 inch seems to be a common size, I supposed I'll use those, unless a longer magnet is recommended...  Then again, I could just as easily use a 1x1x3 inch square magnet, and make my coils pie shaped to fit those instead. I may use this option because of the larger gauss ratings and the fact that they would allow for more hardware in the same space, with equal work on my part...
   I live in the south so I won't be able to get black sand from the roadside due to the large amounts of rust and the like which is probably comprised of old cars. People are poor around here, and theres no state inspection of any kind (Florida sucks, you come to visit on vacation, your car gets rusty, and you leave with lung cancer on probation, and come back in six months on violation and die because the state medical practitioners have to charge double to pay thier insurance. Sorry, that wasnt a rant, it just sounded like it!)
   But theres a gold and gem mine nearby, they sell bags of the stuff for tourists to go panning, so I can go there and get some sand. I hope it works as well as it's said to.
   I'm planning on a 4 foot dual rotor setup, with the coils stationary in the middle. I'm thinking about running continuous coils, in two rings around the periphery of the stator, each ring will produce single phase AC, and they will be arranged 180* out of phase, which will give me two phase AC out. Hopefully I can make the two separate rings of equal proportions so that they create the same results - I'm sure the inner ring will be a little weaker, but hopefully it will be only a few percent...  Theoretically, if I can manage my Rpm's right, I can make 60Hz AC, or close enough to be usefull... But if not then I can build a simple rectifier, and get some stupid batteries. Maybe putting the wild AC into correct phase would be cheaper though, and more cost effective in the long run...
   I will probably use a 16" bicycle wheel for the hub assembly, and ferrous plates or laminate behind the magnets. I could also coat the plate the magnets will sit on with black sand mixture, or just use the black sand by itself, but I'm not sure this would have the same effect as a metal ring behind them. It would certainly be easier.
  Seems like the most intricate part of this whole approach is in getting the magnets close to the coils. Obviously, the larger the wheel the more difficult this is. Even if I could find a truly flat piece of plywood, it would warp in no time without a solid frame, and I don't have room for any kind of framework, even if it could be easily balanced. So I guess that means I'l have to fabricate something flat. Easier said than done. I just thought of a decent idea! I can goto the local thrift store and buy a really ugly table. Then I can coat it with wax and make a fiberglass rotor on top of pre-placed magnets. That way the magnets will be fixed permanently where theyre supposed to be (unless I want to retrieve them). Oh man, that means I'll be itchy for a week! I hate fiberglass, it's like synthetic chiggers >:( (red bugs).  Don't suppose theres a better way to make a flat rotor? I could mix resin and black sand and make the rotor body out of that....
   I was thinking about making the stator out of something that is slotted or notched, so that I can remove coils without dismantling the thing, that way I can fine tune anything that needs it, and I'm sure things will need done differently before I'm settled on any one coil configuration. I was also considering the possibility of making a DC system on a separate interchangeable rotor. Maybe use a set of toroidal coils, made from black sand... Say, would that work better you think? Better than the usual way? Probably not because theyd do it that way if it was, but then Tesla's high freq AC was better (it didnt shock people at least) and they dont use that at all, so...

   Say, I'm not trying to pry, and its way off subject, but what does your solar powerd water generator do? If you could affix it to a standard solar hot water heater then it would be great. Actually, it's great anyway since its free. The Micro-Tide Generator. I'm curious...

fleebell

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Re: I am building a Magneto, need help with the coils...
« Reply #11 on: March 23, 2007, 09:21:58 PM »
Ok, hmmm I've got a few suggestions to make your life easier. If your going to use a 4" diameter rotor use a piece of wood 1/2 - 3/4 max thick and cut out holes in the wood for the coils to fit into. (don't forget slots for the wires to exit from)  fiberglass them in place and leave the leads outside so you can modify your wiring.

 Your coils should be big enough that the magnet can fit completely inside the coil whether they are round or oval and try to keep them as thin as possible - preferably <1/2" but no more than 3/4"  The entire stator needs to be kept as thin as possible and still be stiff.
 
  Make sure you use enough coils and magnets so you can wire them three phase later on. (I can almost bet you will not like trying to keep it at 60 cycles by controlling the wheel rpm for very long and will resort to the battery setup eventually.).
    Use more stiff wooden wheels for the rotor(s).  I agree, a recycled presswood table probably would probably work better than plywood but make sure you seal it extremely well.)  Again cut holes for the magnets leaving maybe a 1/4 " of face sticking out. If using two rotors cut strips of sheet metal to fit behind the magnets (at least 4 layers ) and fit a curve all the way around the wheel behind the magnets.(it should be wider than the magnets) Epoxy or resin everything in place (screw the sheet metal to the backsides of the wheel). If only one rotor the black sand in the coils should do it but don't put any in the coils if you are using two rotors.

   I don't think your going to have enough torque to do two circles but if you at least cut the holes for them the first time you can always go back and add them later if needed.  If you are going to use a bike hub for it I suggest you use a 20" one instead of the 16". Most 16" hubs are crap and you will at least stand a chance of getting something decent in the 20" size

   An alternative would be to use pipe with flanges as the hubs as it would be much stronger and give you something to bolt the rotors to at the same time. Pick a pipe size that will slide over your axle, shim it straight and just pin it to it. Then use regular bearings that mount to a frame with the axle. That would make it easier to hook up your driver to it.  (of just make a big Hugh P style using car wheel parts, that would be the strongest setup and best too for an alternator this big - imo)

 Those small bits of rust won't hurt anything and will work ok if you screen it to get out any large chunks.   That is what I have been using for black sand... I live in Wilmington NC just a few miles from the ocean... same problem with car rust, my neighborhood is about 70 years old and there is plenty of it on the side of the road.   Put the fine stuff in a old frying pan with a little water and stir fry it until it turns black and is totally dry. That will anneal it and put a protective oxide coating on the individual pieces.
  It will work ok to use as black sand then. (at least it does for me)


twilightinsanity

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Re: I am building a Magneto, need help with the coils...
« Reply #12 on: March 24, 2007, 09:09:12 PM »
   Hey man, your suggestion of using a frying pan was resourcefull, and I've never heard of annealing things quite that way before - and I'm a glassblower, so I know about annealing! I suppose I should go offer my services in the Moray Device forum, but frankly I'm afraid somebody will want me to do vacuum tubes full of  radioactive material and I don't wanna lose sleep because my eyelids are glowing...  :o
   Anyway, I was thinking about the process youre using to aneal the iron particles, and it seems sound (though I dunno how hot the iron has to get to create the proper results, I thought it had to get hotter than a water bath on a stove would allow, oil would seem to be a better choice, but maybe I'm thinking about tempering...)
   I knew a Viet Nam Vet, gone now, who showed me a nice trick once. He said that during the war the rain made everything get rusty, and when your life is depending on your gear you learn to keep the rust at bay. He showed me an old case xx pocket knife that was very rusty (you know how black bladed knives rust) He dipped the blade, rust flakes and all, into a jar of plain yellow mustard and laid it aside. The next day the mustard had turned black, and rubbery. When I peeled it off the blade was shiny and black, without a hint of rust. The copper knife body turned a sort of pink color though, so the acids in mustard arent good for making copper pretty. Mustard works as wel as ospho from what i've seen, and its cheaper and safer, and easier to come by as well. One good trick deserves another, so I thought I'd tell you this one in return for the iron filings in a pan one...  ;D
   Umm, I think the iron filings will retain an EMF feild longer than the black sand, I'm not sure but it may even defeat the purpose. What I mean is that if the filings hold magnetism, then they would induce magnetism in the black sand as well, for the length of time the iron retains it's magnetism. I'm in georgia, and they have a lot of mines around here, I bet they do on your side of the mountains as well. Just saying that maybe theres a simpler and contaminant free way to get sand, rather than using a magnet.
   So, since I'm using two rotors, I won't need the cores? Do you think they'd make it less efficient, or harder to turn, or just wont do any good with the extra magnet on the back of the coils?
   I think your suggestion of car hubs would be a good idea, but I don't wanna overkill either, bigger parts mean more bearing drag... Then again the more I think about it the better the flanged pipe idea sounds to me. I guess I'll figure it out soon enough, I plan to start on this thing soon, my magnets are not ordered yet, because of size considerations, but when they get here I hope to have everything else about done.
   I have a strong feeling youre right about my torque not being enough to do two rows, (maybe even one!) so I think I will make a stator that has notches cut in it so that I can remove and replace coils very easily. That way I can try different wiring configurations and coil types. I wish I could think of a very simple way to make the rotors adjustable for width as well, but so far all I can come up with is washers. I'll make it so that the stator is 1/2 In thick, and separated from the rotors by as little space as possible, hopefully I can make everything flat enough to get 1/8 or even 1/16 air gap between the parts.

   Slowly but surely, it's coming together. With an interchangeable design I won't have to worry about exacting coil specifications yet, which makes the whole thing a less cumbersome idea. I may also make another wheel or two to add to my overall torque ratio. I can't see how to get more Rpm's without a vacuum tube the size of a storage unit, and then I'd only get about ten or twenty percent, so my object must be for more torque, which is easily attainable...

fleebell

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Re: I am building a Magneto, need help with the coils...
« Reply #13 on: March 24, 2007, 09:57:50 PM »
Thanks, I've never heard of the mustard trick before, I'm going to try that.  Don't use oil in the pan, the water is there because it has to do with the chemical reaction that that blackens the iron particles. (alpha hematite into gamma hematite)(sp?). Not really needed but helps keep them from rusting in the epoxy. They will work ok, it you use fine stuff as it's pretty much the same thing as black sand although you will not need it if you use two rotors, it will just absorb some of the field and you don't want that as you have the other magnetic field to use instead.
 Yes, car hubs do have more resistance to turning but you can take out most of the old grease and loosen the preload on the bearings and they will spin pretty freely and that will make a big difference, light oil would work just as well as the bearings will never be stressed in this usage.

 I prefer using the pipe fittings as you can modify stuff a lot easier that way if you need to. (I have a lathe and learned to do aluminum casting a couple of years ago- it makes building things much easier when you can make your own parts if needed)


twilightinsanity

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Re: I am building a Magneto, need help with the coils...
« Reply #14 on: March 25, 2007, 11:06:32 PM »
   Well, I've gathered enough information (thanks for the help!) to begin making everything. It will be awhile before I have all the parts, and I really can't begin untill I have measurements for everything. I am going to make one continuous row of air-core coils, with two rotors. I'll either use circular 2" coils and circular 1" magnets, or if I can afford it I will overkill with 1"x1"x3" rectangular magnets and oval/pie shaped air- core coils. I'l go with thirty windings first, and see how that works. I'll make slots in the stator so that I can change out coils easily, and rewire different patterns as well. Fiberglass is probably what the stator and rotors will end up being made of, minus whatever the metal backing for the magnets I can find. The hubs will probably be made from whatever light automotive hubs I can find, I'll need two, so maybe I can get a whole rear axel from a FWD vehicle...
   If this dose'nt work it will be because of low torque, but if I have to I can make more torque as needed. The 4' wheel size should compensate for the lower Rpm's. Hopefully it won't look too ridiculous when I'm done.  :D
   I'm not in posession of a decent digital camera, and the magneto is basically the same as the one it's modeled after except the diameter is doubled and the number of magnets is increased, the number of coils is larger too, but I dont know if it's doubled or tripled since I think they only used 15 and I'l need 50+ (though maybe theyll be smaller ones).

   That was a most useful link you sent, and I'll repost the specific windmill model I found and will use here:
   http://www.otherpower.com/20page1.html

   So, regardless of the actual efficiency and workability of my idea (and more importantly, my workmanship) I am guaranteed to be able to make at least 100 watts of constant wild AC (I'm not sure, but I don't think it's actually gonna be wild. Depends on the definition...)  It will be steady and constant at its frequency. With exacting mathematics and construction, that frequency could be 60 Hz. But in my case it will probaly be a steady 45-90 or so Hz. Possibly I could get more power than this, as much as 12 Kw with enough torque at the shaft (or magnets in this case).
   More Rpm's would be great, but that aint gonna happen with my fine all wood and concrete construction - besides, it's most efficient at about 40 Rpm's.
   If it works I'll celebrate the occasion with a digital camera so I can post pictures of the whole thing. If it works well enough to actually do more than light up a bulb or two (which wouldnt be worth the cost or trouble of construction) I'll take it apart and film the process of putting it back together again, or of making another one. I'll also lay all the parts out on a piece of grid paper and take a picture so that people will know what sizes I used. (I often wonder why others don't do this...) None of that should really matter though, because what I am building isn't exactly new material, it's just another magneto stuck to a waterwheel. Sort of...

   I guess my newest, and last, concern is where to buy magnets and coil wire online, and what type of magnets to get, and whats a good price to pay for em, and do they ever wear out (under any circumstances?), and I guess that'll be it. Oh yeah, how much waste heat do you think this will generate? Probly depends on wire size huh...