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Permanent Magnet rotor.
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Srinath
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PostPosted: December 28, 2009, 7:57 pm    Post subject: Permanent Magnet rotor.

Is there a market for a permanent magnet alternator rotor that is a drop in swap.
Remove old one, put this one on. Fit a suzuki regu/rectifier after doing a wire match. That simple.

Target $ - possibly around 100 for the pre 80's and 125 for the 80+ which have the pickup trigger in the rotor.

Just a feeler. It may happen, or it may not.

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Tomterrific
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PostPosted: December 29, 2009, 1:35 am    Post subject: Re: Permanent Magnet rotor.

Just so you know, a ring magnet can't be put in the middle instead of the coil. It won't work. It would be a nice modification to have a drop in PM rotor and easy too.

Tom Graham
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Srinath
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PostPosted: December 29, 2009, 11:05 am    Post subject: Re: Permanent Magnet rotor.

OK why does it not work with a ring magnet and that is a question to just check what you know, so dont have to answer that. I have actually modded the rotor to take that and work too, just more $ and less power than I like.
And I am not putting a ring magnet in there ... I am fabbing up a rotor if things go right, and I am even thinking I can offer 2 different power versions. One for kick start only and one for the full on xs wiht an extra set of running lights.

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yamaman
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PostPosted: December 29, 2009, 11:37 am    Post subject: Re: Permanent Magnet rotor.

Srinath, it's a big statement to make, that you can produce a perm mag set up with power to burn just by changing the rotor!...........I'd say yeah, there would be a market for sure...............Will take a lot to prove your system up though......Let us know and post some pics when you get it running.
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Srinath
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PostPosted: December 29, 2009, 11:44 am    Post subject: Re: Permanent Magnet rotor.

Yea I know. I am working on it still. I had some success with that ring mod he mentioned. However it was too $ and too weak. Plus I will not be able to sell it, I'd have to collect your rotor and modify it etc etc. I am hoping to get this worked out and be able to pack and send it with nothing else on your part - yes a regulator swap is needed, but a suzuki reg is a direct swap. red to +, black to - the 3 white ones from the xs to the 3 yellow on the reg and ignore the brown and green on the xs.

Anyway I will post back how it works.

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pamcopete
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PostPosted: December 29, 2009, 1:11 pm    Post subject: Re: Permanent Magnet rotor.

srinath,

Well, you could make a combo unit. Part permanent magnet...part wire winding. The magnet would get you started...the winding would produce the majority of the current output.

With this arrangement, you could:

1. Have a kick start no battery setup.
2. Continue to use the stock regulator.
3. Produce enough current to run the ignition system alone on the magnets for a get home mode.
4. Overcome the problem you have now trying to build a magnet only rotor.

The whole setup would work just fine with a PAMCO ignition because the magnets would only have to produce 6 volts at 2 Amps to start and run the engine to produce another 2 Amps to excite the winding on the rotor and the whole deal would then bootstrap itself to produce the full 14 volts at 9 Amps.

Use low power headlights and LEDs to reduce the total required current to 7 Amps.
You would have to switch everything besides the ignition off when starting.

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Srinath
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PostPosted: December 29, 2009, 1:45 pm    Post subject: Re: Permanent Magnet rotor.

Well, the ring magnet isn't going to allow room for winding of any kind.
I calculated 250 ft of 24 guage wire for the original rotor. I dont have a way to stuff even 1/2 that with the magnets cos the magnets take up all the room.

Any case so far I have not run into any problems, I bought the metal and that is my present situation.

Oh I could make that rotor out of mild steel with a coil inside and the magnetism will be permanent plus when there is current in the coil its got more magnetism. OK fine. I could in that case get away with a small coil and get the steel magnetised. Naaa I am too far into the current line of thinking. If I am buying a coil ... its just about the same with the one I have.

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pumps
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PostPosted: December 29, 2009, 2:28 pm    Post subject: Re: Permanent Magnet rotor.

Srinath- I don't know if you have read this post on how a guy rewound his rotor or even if it would help you but I remembered reading it quite a while back. What brought it to mind was you mention calculating the amount of wire needed. This guy used 22AWG
and 325 feet of it. Hope this helps. John

650rider.com/index.php...r%20rewind

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Srinath
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PostPosted: December 29, 2009, 2:53 pm    Post subject: Re: Permanent Magnet rotor.

Yea I did read that, there is 2-3 things that have happened in the last 2 weeks since I started on this crazy project.
OK 22 guage is fine 24 guage will let more windings, less current and more magnetism and I roughly calculated 250 ft from resistances of wire ... somethign like 25 ohm 1000 ft for 24 guage. So 22 obviously is lower resistance and goes to follow more needed for same ohm value. Anyway besides the point.
I found out I can buy a self supported coil or air core coil for these quite inexpensively, so winding it myself is out because buying it is fine.

Then I calculated its approximate gauss value, figured out that is easily attained by fitting a bunch of magnets on a aluminum drum. Easier and cheaper and well, I can control the power too ...

Anyway I have some of it started, the thing if it flops I will drop back onto this method I am sure.
And with a wee bit of machine work I would be able to do that semi permanent setup like pamcopete mentioned. All good ideas. I just started on what I think is the easiest ... maybe not ...

Anyway a GS500 alternator swap is simplicity itself.
Its got the 3 from the stator and the 2 - positive and negative. Easy.

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Srinath
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PostPosted: December 29, 2009, 3:04 pm    Post subject: Re: Permanent Magnet rotor.

Oh you can buy a type of wire that is enamelled (obviously needed) and is already epoxy coated at the strand level. The thing is, it will have to be wound, then heated to 400 degrees for a few mins and it will bake itself on. 1 sec lemme look for some links. Well google self supported coils and you'd see.
I am just thinking the method I have now is easier, and takes less of my time, which I am finding scarcer and scarcer.
Besides, no need to preserve the epoxy plate. We dont need it. In fact the whole rotor can be trashed.
Needless to say ... I have to prove ... or disprove it.
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Srinath
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PostPosted: December 29, 2009, 3:27 pm    Post subject: Re: Permanent Magnet rotor.

OK so here is the theory.

Buy aluminum - round 4 inch solid 2 inch length was what I bought with 1 phone call.
Then take the rotor off - I have a few spare dead ones one of which I split. And give it to your favorite machinist. The aluminum too. OK so this is where I am right now.

The inside taper and the key way need to be cut. And that may need the wood ruff key modded a little. But I'll deal with it when I have it completed. easy enough.

Then I bought these monsters. 50 of them in fact. Cost me 45 bones and if this idea flops, I am using it to stick my GS500 up onto my garage wall.

www.kjmagnetics.com/pr...50&cat=168

So now drill and mill and thread 48 or how many ever you please, holes on the machined aluminum. Conveniently it measures a foot around, so 1 inch c/c 1/2 inch dia holes 2 rows are about right for 24 of the magnets.

You can do a square block of 4 X 8 for the original style pole configuration.

The of course 2 positive, 2 negative in my configuration or 4+ and 4 negative in the other configuration. Screw in the magnets with some small head allen bolts. Yea yea put epoxy under it whatever ... details details ...

Fit the bugger on and go for a ride ... oh wait before that check voltage, amperage and your butt's resistance cos if it catches fire you dont want your butt to conduct electricity and fry you ... yea yea fit a suzuki regulator.

Anyway, magnets on a drum ... run with it.

The rough math ... stock rotor makes something like 730,000 gauss at the surface. It actually sits rather far away from the coil and machining it precisely will let me cut that distance in 1/2 or even tighter, but I digress.
That magnet is 14,500 gauss and I mount 24 of it on my drum and a 4 X 8 config like stock will let you fit 32.

Yes now you may say 730K gauss is much more than 14.5K X 32 even.
Yea, here is where some efficiencies come in.
1 That rotor eats up 2 amp-3 amp. 36 watts gone in a 200 watt system ... 20% lets say.
2. Then heat kills the permeability of steel. On mine - well there is less heat cos its only what is sent through the crank, and there is a ton of aluminum spinning quite fast which will effectively let it run at ambient +50 max.
3. The rotor has a V shaped pole configuration and it has a ton of interference from the adjacent pole and the fact that its not a sharp swap from N-S. Mine in both the 4X8 combo and the 4X6 combo are sharp hits of N then S, then N ... it will make each hit of the pole return more electricity in the stator. K that is my story and I am sticking to it. More magnets if its too weak, less if its too strong, and rotor winding if it crashes and burns.

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Srinath
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PostPosted: December 29, 2009, 3:36 pm    Post subject: Re: Permanent Magnet rotor.

I now see on that other thread that Xsjohn suggested this mod to the stock rotors. Yes ... however the stock rotor is made of some weird ass cast and sintered garbage that machining it could cause you interminable grief.
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dpmphoto
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PostPosted: December 29, 2009, 8:00 pm    Post subject: Re: Permanent Magnet rotor.

I applaud your enthusiasm but Why not just take what's already been proven and engineered by professionals and go from there. You could buy a used banshee flywheel on ebay gut it and try to improve the magnetism maybe with rare earth magnets.It already fits perfectly on the xs so the only thing to worry about would be the magnetism. There's about 3 dozen coils that will fit perfectly inside the banshee and mount to the xs with ease either using a simple plate or the improved banshee timing plate.So then take the coil(stator) and see if you can increase the windings or resistance. What's wrong with the regular banshee mod anyway?,mine all have several 1000 miles without any problems and costs me an average of about $120 a piece if u need a little more juice just be careful which stator or coil you choose for the mod there's about 3 or 4 dozen that u can use.
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Srinath
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PostPosted: December 29, 2009, 8:23 pm    Post subject: Re: Permanent Magnet rotor.

Banshee rotor wont work on 82, timing is in the rotor.
I can rewind mine or make from scratch. Of course I'd index and install the magnet for the timing in it.
My choice in any case for the mod will be a gs 500, I have one sitting here and I know it'll work for about the same type of work as a banshee rotor.
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Tomterrific
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PostPosted: December 29, 2009, 9:18 pm    Post subject: Re: Permanent Magnet rotor.

The ring magnet in the center of the stock rotor will not work because the claws act as a magnet keeper when the claws are pressed together. The poles of the magnet are shorted through the center. If the center of the claws were non magnetic stainless steel, the araingment would work.

I've thought about some neodymeum disk magnets sercured to the fingers of the claws to get the initial charge. I suppose the challenge is to keep the disks from flying off.

Tom Graham
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Srinath
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PostPosted: December 29, 2009, 10:45 pm    Post subject: Re: Permanent Magnet rotor.

No they wont short pole to pole. The problem is that the inside of that rotor is coated with some type of sheilding. Outside to in magnetism flows just fine, Inside to out it does not.
I believe that is to prevent or reduce the effect of the coil which will be inside the claws, and that will negate the effect of the magnetism that is created from the center outward. So if you were to scrape or grind or machine that core on the inside like I did, it will send magnetism through in both directions and unfortunately I will ahve to break another core open, chip off teh lacquer and not grind it if I am to wind it like it originally used to be.

And the person that blasted the rotor with bead if they got in as deep inside as I did with my grinder, pretty much is getting some of the magnetism cancelled ... maybe not enough to hurt. But making a rotor to wind is sorta not that great.

Of course the claws etc are cast and are poorly suited to holding magnets with any sorta threaded fitting. There by the need to make a drum buy a whole bunch of mondo strong magnets and screw them in.

To use the large ring magnets like you're describing, the rotor should be made of a very magnetisable metal. It has to have very high permeablity and very high inductive magnetism. Mild steel fits that desctiption perfectly, it can be welded etc at will cos weld still conducts well, so I'd make a bobbin out of steel, make claws by hand grinding a pipe into that multiple W shape, and weld all them. Then spin and balance it for weight and then stuff magnets in the center and call it a day. IMHO, too complicated. Machining is better, its a balancing process too if you think about it. Usually 60 series aluminum is very consistent in its matrix and comes out near perfect. No wonder they make air planes out if it. Anyway a chunk of it may soon be inside my XS. Lets see how it goes.

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dpmphoto
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PostPosted: December 30, 2009, 3:48 am    Post subject: Re: Permanent Magnet rotor.

Wish I had that much free time
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Srinath
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PostPosted: December 30, 2009, 9:44 am    Post subject: Re: Permanent Magnet rotor.

Wish I had the $ to buy a new rotor.
Anyway lets hope this magnets on a drum idea works.
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Srinath
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PostPosted: December 30, 2009, 10:06 am    Post subject: Re: Permanent Magnet rotor.

Oh, if I wind it with 24 guage wire, I probably can get 400 ft+, and prolly 500 turns in and have 10-12 ohm resistance. That would pull down 1 amp and make more magnetism cos its turns X current. May be a thought ...
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yamaman
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PostPosted: December 30, 2009, 11:16 am    Post subject: Re: Permanent Magnet rotor.

Just do this & be done with it!

www.650motorcycles.com/UJ.html

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Srinath
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PostPosted: December 30, 2009, 11:25 am    Post subject: Re: Permanent Magnet rotor.

Mu haha ... car crap ... I have one of those sitting I borrowed from my mechanic.

My idea was to see what car had the same coil size and buy one ... but well I like my magnets on a drum idea for now.
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yamaman
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PostPosted: December 30, 2009, 11:29 am    Post subject: Re: Permanent Magnet rotor.

Ok Srinath, was just havin a laugh!

Have you seen the setup 3/4's down this page:

www.xs650.org.au/kev's%20turbo.htm

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PostPosted: December 30, 2009, 12:33 pm    Post subject: Re: Permanent Magnet rotor.

Yea That one I have seen ... seems like a ton of work ...
I want to fit this back together and sell it.
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