GStwin.com GS500 Message Forum

Main Area => For Sale / For Trade / Wanted / Hot Deals => Topic started by: SV_Hadder on June 07, 2011, 10:37:28 PM

Title: WTB: GS500 Rotor (I have Goat's)
Post by: SV_Hadder on June 07, 2011, 10:37:28 PM
I'm looking for a good rotor for my 1993 GS500, as she was just diagnosed with Goat's.  Searched ebay and no luck.  If a GS500 rotor can't be found easily, are there any substitutes?

My zip is 27530 and I will pay via paypal!

Thanks,
Zach
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: burning1 on June 07, 2011, 11:03:14 PM
Hi Zach, I have a couple extra. No new, but serviceable. I won't be able to ship out for a week or so though. Let me know if you're interested.
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: werase643 on June 08, 2011, 06:39:40 PM
I got one in central NC that I just took off a crank today
looks good
been sitting inside for 15 yrs

can get it out to you in a day

Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: MacV on June 23, 2011, 04:15:21 PM
Im also looking for a rotor, either of you guys have a price?
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: SV_Hadder on June 24, 2011, 09:35:26 AM
I got mine from a 1981 GS450.  It cost me all of $27 INCUDING shipping, and it is in phenomenal condition!  Most of the older style rotors will only have 3 magnets, but I have had no adverse effects yet, and I don't plan to.

I found this thread when I was looking for a rotor, http://gstwins.com/gsboard/index.php?topic=52561.0 
I am not POSITIVE, but I think it is pretty accurate.  eBay has plenty of GS500 alternative rotors!

Good luck,
Zach
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: werase643 on June 25, 2011, 07:34:52 AM
with the 6 magnets....your system has 225 watt output

with 3... i haven't found the output of a GS450????

to do your charge test at 5000rpm.... you will now probably have to do it at 10000 rpm

i'll do a little research...but anybody here can do a little research
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: aussie-gs on June 26, 2011, 02:47:56 AM
Stripped my motor found I have goats now after a rotor .
Can anyone help with a good 6 magnet unit. :icon_question:
Read somebody put a bike rebuild goes from one thing to another , it will end up being like new when I am done.
Also found the balancer shaft front bearing worn badly so that needs to be replaced as well  >:(
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: burning1 on June 26, 2011, 01:49:08 PM
What is GOATS?
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: aussie-gs on June 26, 2011, 02:11:03 PM
Do you have any rotors?
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: aussie-gs on June 27, 2011, 12:09:54 AM
Anyone got a rotor
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: Unsane on June 27, 2011, 01:40:15 AM
Quote from: burning1 on June 26, 2011, 01:49:08 PM
What is GOATS?

X2  :dunno_black:
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: aussie-gs on June 27, 2011, 02:18:03 AM
X3 :dunno_black:
Copied from title thought other would know ,but anyway obviously not  :D
Anyway back on the subject does anyone on this forum have a rotor that they want to sell :icon_question: Looking for one so I can rebuild my motor, or do I have to post pictures before I get a response.
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: SV_Hadder on June 27, 2011, 10:41:07 AM
Goat's is named after the first person that had this problem.... The problem?  Magnets inside the rotor coming unglued, and wreaking havoc on the stator, and the rest of the engine.  It is NOT an acronym lol.  I think the person's username was "Goat", if you do a search you will find quite a bit of information.

Hope that cleared things up a bit!   :thumb:
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: jeremy_nash on July 06, 2011, 08:00:55 PM
I ended up buying one from buddha, because he shipped to me quicker than I thought the ebay sellers would have, at a comparable price to the older, 3 magnet rotors.  According to electrical formulas, the ac cycling frequency would be cut in half, how that would translate into a diminished output, I'm not sure.  Glad my old post was helpful to someone though!
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: noiseguy on July 07, 2011, 07:29:21 AM
Someone should add "goats" to the wiki.
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: The Buddha on July 07, 2011, 08:43:07 AM
You can nowadays get those curved magnets from a place like KJ magnetics. However those buggers are really really really powerful. That will result in tons of electricity ... you can fry stuff easy if you're not careful.

I actually tried to replace a electromagnet on a xs650 with a permanent magnet made by bolting a bunch of the little magnets to a bobbin before giving up and selling the xs. The GS is a drum not the bobbin style, so you will need to do different type of fitting, but you can get the small magnets and screw them to the wall, make sure you get it balanced though a nicely machined aluminum piece will have great balance, then the bolt holes, then thread em then screw the little magnets in in a 6 pole pattern, they put out like 10 X the power of the old school ones, so you can put in less or have them further away from the coil etc.

Go to kjmagnetics.com and check it out, an N52 magnet is just about 10X the power of the n5 we have in the soft iron original one.

Cool.
Buddha.
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: The Buddha on July 07, 2011, 08:48:27 AM
http://cgi.ebay.com/5-pc-N50-2x1x1-2-NdFeB-Neodymium-Magnets-w-Hole-Block-/220807651168?pt=LH_DefaultDomain_0&hash=item3369295f60

Buy that bugger and 5-6 of it, fit it inside a drum machined to take the place of the rotor and watch the GS make enough electricity to light up a whole town. Besides, you'll never get goats the Neo magnets are super hard, too hard to machine really, they wont disintegrate just from the vibrations of the motor.
Cool.
Buddha.
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: The Buddha on July 07, 2011, 09:01:23 AM
If your stock rotor is good you can somply clean off the inside off the magnets and drill and tap it for these buggers.

http://www.kjmagnetics.com/proddetail.asp?prod=BX082CS%2DP&cat=173

Toss in 3 pairs of them and watch what it does. I have a feeling you'd have to ratchet it down to maybe 2 pairs.

Now if someone will pay for it, and send me a DOA rotor and not be in a freaking rush I will do the experiment. I actually can sell a good rotor with the bad one as trade ... I need the rotor I have but can experiment ...

Cool.
Buddha.
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: noiseguy on July 07, 2011, 11:11:56 AM
So I'm looking at the specs for the magnets. Which one needs to be equivalent for our use? Seems like you'd shoot for equivalent gauss rating and approximately the same size, ideally. That would be the "same thing"

Since these Neo mags are more powerful, we'd use a smaller magnet. In that case, it's something more like pull force at the surfaces of the magnet. That, at least, is easy to measure. Just try to pick up heavier chunks of steel until it won't, and that're your rating (or use a spring-pull force meter, like used to weigh fish). Quick call to the vendor might turn up some insight on replacements.

You'd want to balance the rotor when you're done... it rotates at up to, what, ~11K RPM? Little imbalances could prove problematic at those rotation speeds. 

http://www.kjmagnetics.com/proddetail.asp?prod=BX082CS%2DP&cat=173

Pull Force, Case 1: 7.49 lbs
Pull Force, Case 2: 29.03 lbs
Surface Field: 2186 Gauss
Brmax: 13,200 Gauss
BHmax: 42 MGOe
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: The Buddha on July 07, 2011, 11:17:15 AM
The neo mags are more power so you'd cover less of the surface to start with. That would be my first line of attack.
Then of course the magnets are thinner and hence further away.
Then I'd do 4 pole instead of 6.
So past these 2 I'd do anything else. I think these 2 should do it. BTW you'd need to slap a soft adhesive strip and/or washers under the magnet, else the center of the magnet will not have a bearing point cos the rotor is curved but the magnet is flat.
Cool.
Buddha.
Title: Re: WTB: GS500 Rotor (I have Goat's)
Post by: noiseguy on July 07, 2011, 01:17:12 PM
I think that the poles need to be phased the same, and in multiples of 3. So, either 6 or 3 magnets. Otherwise you won't get 3-phase power out of it... you'd get something else. The stator has 18 poles... I'm not even sure if it would work with 3 magnets... I'm not sure there.

The distance thing would be tricky... more powerful at farther distance... strength falls off exponentially as distance is increased... this would need to be tightly controlled. I'd be tempted to glue a piece of steel on top to set the air gap to the right distance.

I wouldn't use a soft adhesive. You'd be creating a wicked spring-mass system on the rotor at operating speeds. You need a nice, hard, high strength epoxy.
.. :)
Curved magnets are available from these guys... looks close. Would be closer than a flat one, anyway. Thing is, at $9/pc, not sure that this is really any cheaper that just sourcing a used rotor. :)

(http://www.kjmagnetics.com/prodimages/AX2C45NL.jpg)

http://www.kjmagnetics.com/proddetail.asp?prod=AX2C45%2DN