External Alternator

[alton_blair]

If you would use one of these
http://www.americanpowerinc.com/police.htm
I would have to think your battery could handle sitting in traffic for a long period of time because it would be fully charged. This is definatley not my strong suit, but high output even creeping forward in traffic should be faster charge times right?

 

[reddirtrider]

If you would use one of these
http://www.americanpowerinc.com/police.htm
I would have to think your battery could handle sitting in traffic for a long period of time because it would be fully charged. This is definatley not my strong suit, but high output even creeping forward in traffic should be faster charge times right?

Your battery can only charge so fast. It's tiny, so it doesn't need a large alternator. That bad boy is meant to deliver lots of current that is needed in an ambulance (quite a bit of medical equipment to power). The motor also drives the alternator, not the rear wheels.

If you're not moving then the alternator won't be spinning in order to develop current, so you'll be running off the battery.

It's probably as much work to tap off the countershaft as it is the crank. If you use the crank then the motor width is reduced and you get more bang for the buck. In addition you're not running off the battery when stopped.

A motorcycle alternator will work fine. At one time I was thinking of doing something like this and using one from a ZRX1200. If you have the necessary machine tools it might be worth trying, but after farming out several jobs to machinists for the 1100 mods I realized it was out of my budget.

 

[alton_blair]

Your battery can only charge so fast. It's tiny, so it doesn't need a large alternator. That bad boy is meant to deliver lots of current that is needed in an ambulance (quite a bit of medical equipment to power). The motor also drives trhe alternator, not the rear wheels.

If you're not moving then the alternator won't be spinning in order to develop current, so you'll be running off the battery.

Ok good point I will shut up now.

 

[makenzie71]

well before I get crazy stuff going I'm trying out a new stator/regulator/battery to see if that cures my issues. All the aftermarket pieces claim higher output so we'll see. I'd really like to rewind my own with heavier copper (14g) but I don't know how to calculate how many turns it'll require to get the propper voltage.

 

[reddirtrider]

Ok good point I will shut up now.

No need. These forums are about ideas. There's no such thing as a bad idea unless it's implimented and costs lives or money. It's good to hear differing viewpoints.

I'm an engineer so I look at the negatives of any idea before the positives. Please don't interpret that as criticism.

 

[alton_blair]

No need. These forums are about ideas. There's no such thing as a bad idea unless it's implimented and costs lives or money. It's good to hear differing viewpoints.

I'm an engineer so I look at the negatives of any idea before the positives. Please don't interpret that as criticism.

I don't, but I will step back and let the more knowledgable people have a crack at this and enjoy the read.:-k These are the things that could make our bikes even more reliable and enjoyable.

 

[reddirtrider]

well before I get crazy stuff going I'm trying out a new stator/regulator/battery to see if that cures my issues. All the aftermarket pieces claim higher output so we'll see. I'd really like to rewind my own with heavier copper (14g) but I don't know how to calculate how many turns it'll require to get the propper voltage.

Well, the idea of driving an alternator from the crank isn't new (obviously). I do think that although it hasn't been offered as a product, there still would be a market for it for 2 reasons. One would be for those such as yourself that want more electrical power. The other would be for those who want a slimmer motor. The cost of development and production would be the limiting factor for most GSer's. Check out how much the external starter kits cost for a baseline.

 

[Billy Ricks]

For what it would cost you could probably drop an oil cooled GSXR engine in your frame and have an external alternator. If you seriously want to try an adapt one take a good look at how Suzuki did it on the early Gixxers.

 

[rustybronco]

I'd really like to rewind my own with heavier copper (14g) but I don't know how to calculate how many turns it'll require to get the propper voltage.

14ga wire will be to much to large I suspect. probably somewhere around 18?ga me thinks.
also see...
http://www.thegsresources.com/_forum/showthread.php?t=134690
http://www.thegsresources.com/_forum/showpost.php?p=968723&postcount=98
http://www.thegsresources.com/_forum/showpost.php?p=967880&postcount=85

Without changing the stator, there is an extra 34 watts avaliable to the load if required so that is about a 20% increase in avaliable output power.

the usage of led turn and brake light bulbs will add to the power available...

 

[Billy Ricks]

14ga wire will be to much to large I suspect. probably somewhere around 18?ga me thinks.
also see...
http://www.thegsresources.com/_forum/showthread.php?t=134690
http://www.thegsresources.com/_forum/showpost.php?p=968723&postcount=98
http://www.thegsresources.com/_forum/showpost.php?p=967880&postcount=85

Everything I've seen says they used 17 gauge. It's an odd size but that's what I think the tutorial on rewinding says they used.

 

[makenzie71]

14g may be too big, but 18g is stock...or it's what's in mine, anyway.

 

[reddirtrider]

I believe you want more turns to develop more current.

 

[rustybronco]

http://www.thegsresources.com/_forum/showpost.php?p=968723&postcount=98

Actually the space for winding the copper wire is limited to the distance between the iron core of each pole measured right at the bottom at its narrowest and then divided in half. In practice this relates to maximum 3 layers of #18 or #19 AWG wire.

that's why I had a ? mark. I thought 17ga was used in the rewind tutorial.
maybe Matchless will pipe in again.

I believe you want more turns to develop more current.

more turns require a smaller Ga wire because of the limited space between poles. the smaller ga wire with increased turns will develop increased voltage, less current.

 

[makenzie71]

I'd like to know as well...I was under the impression that heavier guage wire increased output as opposed to windings but in the end I think it's total copper material. Clarification would be excellent.

I'm also still researching compact external alternators. It would be poissible to run two generating systems together to get the additional wattage...so you'd have power through the normal range with the factory stator, and you'd have an additional powersource from an alt tapped off the countershaft. If I could find something small enough to fit under the carbs that would run off a shaft extension from the stator side through a modified cover that would be the bee's knees...get something truely modern and ditch the old stators and rectifiers both.

 

[rustybronco]

I'd like to know as well...I was under the impression that heavier guage wire increased output as opposed to windings but in the end I think it's total copper material. Clarification would be excellent.

it's not the total copper material that matters. it's the number of wires cutting the magnetic lines of force, combine that with the increased resistance of the thinner ga wire. increased turns=higher voltage, increased resistance=less current.

 

[GQROD]

Mounting an alternator off the timing shaft seems to make the most sense and would not cost that much. Since it's dry there other models could adapt this.

You would need a shaft extension and mod a new cover plate but that should be cake for someone with time and a little skill.

Hyundai alternators i know have been used on some custom bikes due to their small size.

 

[makenzie71]

I'll look at hyundai alternators, but coming off that side isn't good because it would prevent you from mounting the alt under the throttles conveniently. It would interfere with the time gadgetry, which may or may not really matter. I guess I'll see how that turns out later.

I'm going the standard route for now, but I am going to look into devloping something here...not only would it be more convenient but you would get a LOT more power for much less money. You can buy used alternators for $20 on eBay all day long and have a generator and stable regulator all in one package. Seems great to me. Only thing is that the transition will be expensive. The whole setup would cost 2~3 times a new stator/rr.

 

[Matchless]

http://www.thegsresources.com/_forum/showpost.php?p=968723&postcount=98
that's why I had a ? mark. I thought 17ga was used in the rewind tutorial.
maybe Matchless will pipe in again.

I have seen many references to the wire guage and have come to the conclusion that some may be measured incorrectly. In the metric system the wire thickness is given as square mm, but the diameter is rather used by all as this is easier to measure. This diameter is the copper only, not including the enamel. So you will incorrectly measure a thicker gauge if you do not first remove the enamel.
Hand winding #16 on an 18 pole stator is just about impossible and you will also lose a lot of space (thus windings) due to not being able to get the windings flush on the bends and adjacent each to other. Using #17 may be a bit easier, but still quite hard to do. Using #18 (metric equivalent of 1.0 mm diameter makes it just possible to hand wind nice tight windings and so get in a maximum of 3 full layers and then another half a layer from the top down.
My guess is that you would not be able to fit 3 layers (at the bottom of each pole) on two adjacent poles with heavier wire than 1.0mm on the GS 18 pole stator.
So basically it is not only the theoretical amount of turns and thickness to get an optimum output, but also the physical limitations that must be taken into account.
Hope this helps.

 

[Matchless]

I'm also still researching compact external alternators. It would be poissible to run two generating systems together to get the additional wattage...so you'd have power through the normal range with the factory stator, and you'd have an additional powersource from an alt tapped off the countershaft. If I could find something small enough to fit under the carbs that would run off a shaft extension from the stator side through a modified cover that would be the bee's knees...get something truely modern and ditch the old stators and rectifiers both.

Have a look at the 18 Amp field regulated alternator which is internal to the motor and was fitted on the CB750 - CB1000 in the early 80's. It may be possible for an enterprising person to fit one of those to a GS???. It will require fitting the Honda electromagnet rotor to the crank in place of the GS permanent magnet one and maybe welding the mounting part of the cover to the GS, to mount the Honda stator and brush assembly.

I would not try it, but the expertise here on the forum could well make it easy for someone to do this?:?:

 

[makenzie71]

Space is certainly an issue, but I'm not hand-winding. I have a nifty gadget I built when I was screwing around making wind turbines. The stator frame locks down in a jig and this gadget applies a measured amount of "pull" to the wire to make the windings very tight and flush. I intend to try and adapt it to work with widing motorcycle stators.

Rewinding bike stators is something I really want ot figure out because there is NO ONE locally who does it. I could make a good chunk of change just from that alone.