Home stator rewind

[POE_333]

My thoughts are that thinner wire will allow more turns, giving you more voltage. However, you did say you would be running multiple wires in parallel, cutting the voltage and adding a bit of current. Not sure how the additional current would compare to simply using larger wire, though.

I am going to try rewinding a couple stators, one using 18ga wire, the other using 17 ga wire to see what the difference is. I expect that the one with the 17ga wire will not charge until the engine is at a slightly higher RPM, but I will be using an FET regulator, which charges a little better at lower RPM, so it might balance out.

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Well, my thought ( coming from an electonics engineering background but not a motorcycle background) the larger the diameter of wire, the more dead space you have between wires when stacked even at an optimal winding pattern. My thought is that the smaller diameter wires ( if wound just right in parallel) would stack better together to take up lesser space ultimately while providing a higher surface current area. And considering the same windings ( im actually considering about an extra 3-5 windings per post) your V would remain constant while alowing I to increase to an extent making it worth the effort. But you gents know a HELLUVAH lot more about motorcycles and their finicky idiosyncrasies then I do. I'm only proposing the theory that id like to try. but if you guys think that id be waisting my time, then im gonna listen.. lol..

[Steve]

Yeah, I have electrical/electronics background, too (but not engineering), but have not (yet) wound a stator. I understand the denser packing theory, I just don't know if you will have enough area increase (current-handling capacity) to offset the smaller wire. It would take a bit of experimentation to find what size wire could be doubled, then wound around the poles, having about the same number of turns.

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[POE_333]

well ive still got the programs stashed away somewhere ( or i can just go to one of my usual engineering websites or just to the math myself which isnt too hard.) I just dont want to be the idiot who didnt listen to the voices who know and might have tried or heard of something similar before. but according to traditional electronics theory, the benefit would be pretty significant.. but in actuallity, i have no grounds for the justification as it compares directly to the manula labor equation.. lol. having never done this to a motorcycle, im at a loss for that experience, but ive wound many a generator before. Another thing.. someone said something about the stator being in an oil bath.. uhhhh... there was no oil under that cover unless im SERIOUSLY drunk or mistaken... please confirm?

[Matchless]

There is oil there, the oil lubricates your starter clutch, starter gears and bearings, splashes over the stator and cools it. There is even a gasket and a rubber oil seal to keep the oil from leaking out!

You are refering to a GS I presume?

[POE_333]

well then im just going to assume that im wrong and "mis-remembering" that lil item.. and try not to stress about it until i pull the cover off today when i get home lol.. but i still do want to know if anyone has ever heard/ done the rewinding with a smaller GA wire doubled up.

[POE_333]

Ok guys, here's the technical stacking as done in a pixel based 100/1 scale CAD drawing with ACTUAL stacking justification results.

I think this will work. Making potentially up to twice the current with the same voltage if I use two wires per post of a 22GA instead of a single 18GA. Granted I don't want twice the current by any means, but 1.5 times sounds VERY plausable to me. Any other comments or thoughts? LikeI said, if ya'll say HELL NO DONT DO IT, then I'm gonna drop it. But if there is any additional supporting evidence that this theory will work as I'd expect logically, then I might just go ahead with it.

[Steve]

Interesting.

Not getting into hard numbers, but I have always heard the rule of thumb that doubling your wire increases the current-carrying capability equivalent to three gauge sizes. Therefore, doubling your 22 gauge would be about the same as a 19. That seems to be a bit less than 18.

A couple other questions. What are the numbers for "total coverage area"? They seem to be rather low if they are supposed to be the percentage of the area covered by wire. The picture for the 18 gauge sure seems to cover more than just 16% of the area.

Also, look at how many more windings you are getting in there. With the 18 gauge, there are 64 turns. With the 20 gauge, there are 100 turns, but since you are splitting that into two wires, there would be 50 turns each. Not sure if the fewer turns would produce enough voltage at lower rpm. Maybe the extra efficiency of an FET regulator might compensate. With the 22 gauge wire, you have a total of 320 turns. Again, split into two wires, that's 160 turns for each. Two and a half times the original.

Seems that the 20 gauge might work, if an FET regulator compensates for the lower output at lower rpm, and the doubled 20 gauge would be the equivalent of a 17 gauge wire.

Thanks for taking the time to work that up, it's something I would have had to actually wind with wire.
For all the effort of the extra wire, I think I will just stick to a single 17 gauge wire.

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[Rkt-Rch]

Smaller wire = (heat) = Less Conformal coat on wire = More chance of short/breakdown etc... Just a thought and somthing i'm seen various times.. Just a thought... Balance A stators got to know it's limitations !!! As Dirty Harry would say !!! LOL

[rustybronco]

Well, there's always the option of using Square Enameled Magnet Wire as suggested by Jim (Pos).

http://www.mwswire.com/microsq1.htm

[POE_333]

Interesting.

Not getting into hard numbers, but I have always heard the rule of thumb that doubling your wire increases the current-carrying capability equivalent to three gauge sizes. Therefore, doubling your 22 gauge would be about the same as a 19. That seems to be a bit less than 18.

A couple other questions. What are the numbers for "total coverage area"? They seem to be rather low if they are supposed to be the percentage of the area covered by wire. The picture for the 18 gauge sure seems to cover more than just 16% of the area.

Also, look at how many more windings you are getting in there. With the 18 gauge, there are 64 turns. With the 20 gauge, there are 100 turns, but since you are splitting that into two wires, there would be 50 turns each. Not sure if the fewer turns would produce enough voltage at lower rpm. Maybe the extra efficiency of an FET regulator might compensate. With the 22 gauge wire, you have a total of 320 turns. Again, split into two wires, that's 160 turns for each. Two and a half times the original.

Seems that the 20 gauge might work, if an FET regulator compensates for the lower output at lower rpm, and the doubled 20 gauge would be the equivalent of a 17 gauge wire.

Thanks for taking the time to work that up, it's something I would have had to actually wind with wire.
For all the effort of the extra wire, I think I will just stick to a single 17 gauge wire.

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Well, for my design model, I had to find the closest form factor packaging to accommodate a closer variance factor to better illustrate the difference in total area coverage of the cross section of each wire. The picture demonstrates that, while occupying the nearly identical volume of space, (the wires at 100x magnification) there is a higher concentration/density of copper in the 22GA wire windings then the 18GA wire. In this example, the 18GA wire cross section occupies 16.085 in^2. Whereas the 22GA wire cross-section occupies 37.699^2 while taking up the same amount of form factor real estate. The theory is the only option demonstrated here. I am aware that the heat would increase exponentially from a lesser gauge carrying the same current/voltage as a higher gauge wire of the same turns and length. However, the illustration was to demonstrate the cross sectional benefit of additional conductive material able to fit into the same original form factor. As the scale illustrates, the cross sections displayed are 100/1 enlargement. This shows us in in^2 that using SIMILAR amount of windings, we can use less wire, taking up less space, and reaping the benefit of additional surface valence conductivity AND throughput valence conductivity. So to sum this up: to use two (2) 22GA wires in parallel, instead of one (1) 18GA, I find that there is BOTH a greater surface area AND cross-sectional area through which current can flow. This is proportional on a parabolic level to the heat loss for the same surface and cross-sectional area of an 18GA with significantly reduced surface valence. The result: hotter wire is the single 18GA according to heat equation. the form factor can be reduced in size to allow for identical passage of current, however, since I'll be using the FH10BA 50A rectifier and I want a few running lights, I'll need a lil higher output to accommodate this. Therefore, a slightly increased voltage output is prefered while maintaining a similar or even lessened thermal effect from identical or even increased current. I'm just asking questions here. But my theory ( I feel) is not yet disproved. Maybe I'm just THAT GUY that wants to be some stupor hero.. I dunno. but so far as I can see, the theory is sound. Effort is not a part of my equation here. It's going to suck to rewind my stator either way... But if I can make it better, why wouldn't I?

[Steve]

Well, there's always the option of using Square Enameled Magnet Wire as suggested by Jim (Pos).
http://www.mwswire.com/microsq1.htm

From what I have heard, it's already quite a challenge to keep round wire nice and tightly packed.
I can't imagine the added "fun" of keeping the square wire from twisting, too.

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[rustybronco]

You haven't considered thickness of the enamel coating on your chosen wire gauge. will the thickness of that coating be the same for each the chosen wire gauges? just one more thing to consider that will reduce the available space for the conductors.

and, you still will have to make a winding tool (bobbin) that can keep both conductors parallel to each other, in order to be able to optimally wind each pole.


you may want to consider using a square cross section enamel coated wire. (my .02)

***edit***

I can't imagine the added "fun" of keeping the square wire from twisting, too.

Incorporate the wire alignment function (a delrin guide perhaps?) into the head of the winding tool.

[Steve]

OK, I now see that the numbers are actual area covere, not the percentage of the area. Makes more sense.

I don't have the engineering background to get into the thermal characteristics and all that, so, although what you said seemed logical enough, it was a bit over my head.

Using the FET regulator will certainly help, but I think the extra windings will really help with maintaining output at lower rpm, if you have your accessories on while in town.

I have a feeling you might get to rewinding yours first, so keep us informed.

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[bakalorz]

Well, for my design model, I had to find the closest form factor packaging to accommodate a closer variance factor to better illustrate the difference in total area coverage of the cross section of each wire. The picture demonstrates that, while occupying the nearly identical volume of space, (the wires at 100x magnification) there is a higher concentration/density of copper in the 22GA wire windings then the 18GA wire. In this example, the 18GA wire cross section occupies 16.085 in^2. Whereas the 22GA wire cross-section occupies 37.699^2 while taking up the same amount of form factor real estate. The theory is the only option demonstrated here. I am aware that the heat would increase exponentially from a lesser gauge carrying the same current/voltage as a higher gauge wire of the same turns and length. However, the illustration was to demonstrate the cross sectional benefit of additional conductive material able to fit into the same original form factor. As the scale illustrates, the cross sections displayed are 100/1 enlargement. This shows us in in^2 that using SIMILAR amount of windings, we can use less wire, taking up less space, and reaping the benefit of additional surface valence conductivity AND throughput valence conductivity. So to sum this up: to use two (2) 22GA wires in parallel, instead of one (1) 18GA, I find that there is BOTH a greater surface area AND cross-sectional area through which current can flow. This is proportional on a parabolic level to the heat loss for the same surface and cross-sectional area of an 18GA with significantly reduced surface valence. The result: hotter wire is the single 18GA according to heat equation. the form factor can be reduced in size to allow for identical passage of current, however, since I'll be using the FH10BA 50A rectifier and I want a few running lights, I'll need a lil higher output to accommodate this. Therefore, a slightly increased voltage output is prefered while maintaining a similar or even lessened thermal effect from identical or even increased current. I'm just asking questions here. But my theory ( I feel) is not yet disproved. Maybe I'm just THAT GUY that wants to be some stupor hero.. I dunno. but so far as I can see, the theory is sound. Effort is not a part of my equation here. It's going to suck to rewind my stator either way... But if I can make it better, why wouldn't I?

I couldn't see your drawing ...

But, a couple of things:

to get similar current capability and heat rise you would need 2 parallel conductors of 21 guage to equal a single 18.
For an equivalent # of turns, (twice as many for the paralleled 21 guage)
you will have an equal area and only equal current capability.

I wasn't able to see your drawing, but I suspect that you cannot get more copper area to fit in the area you have to wind it. infact, I suspect that due to difficulties winding it, you will be able to get in fewer turns, thus resulting in less voltage.

Additionally, assuming an equally thick coating of varnish on the wires, the varnish takes up a proportionately larger percentage of the 18 guages available winding area.

Better conduction due to the extra skin area is irrelevant in this application, it only applies at very high frequencies.

You didn't show the heat calculation, but I suspect it ends up misleading as well. It will assume that the 18 and 21 guage wires have similar environments, but this ends up not being true. effectively the 18 guage wire has a greater percentage of wires "inside" the bundle, where they cannot reject much heat because all their neighbors are hot too.
In the end it winds up a wash between 18 and 21 guage.

I don't think using a pair of 21 guage wires will hurt (assuming you can do as good a job winding them, which I actually doubt) but it won't gain you anything either.
BTW, if you DO use a pair of parallel 22 guage wires, you will have less area, less max current, and more heat (a loser all the way arround)

[doctorgonzo]

Remember seeing some posts on here incl one very comprehensive one a year or so back... guy doing it in his office at work

Personally for what they cost aftermarket & the hassle involved I think I'd buy one.

Same here. The number of hours of my life involved in winding one is worth WAY than $130.