Charging rotor disassembly... if you ever wondered...

penn71911

OK, First, thanks to Weekendrider for donating the already shorted rotor for my little experiment.

So I started by softening up the epoxy (a little Rolling Eyes

) by soaking the rotor in paint stripper for a day or so... careful not to submerge the top plate with the copper bands. It didn't actually 'soften' it, more like made it crumbly... which worked out.

Next, I welded up 4 bolts to a piece of scrap metal so that they contact the teeth on the front half of the rotor (see pics)...

I marked the halves with a scribe so I can put them back together correctly lined up.

Now... YOU should use a press... it's safer for the rotor... but I used a piece of aluminum as a block (so as to not screw up the threads) and a couple whacks with my favorite BFH and it popped apart.

The wiring came out in a wad, looks like a mile of the stuff Smile

... I noted which teminal leads to the inside of the coil and which was the end (outside)... and which direction it was wound... I don't know if it really makes a difference, but worth noting I thought.

pamcopete

penn71911

You can remove the top part with the copper slip rings. Those dark spots around it are plugs that cover screws underneath.

If you are going to rewind it yourself, measure the thickness of the wire to figure out the gage (I think it's 22 gauge) and then get a chart that will tell you how many feet of 22 gage wire it takes for 5 Ohms at room temperature. 22 gage wire is 60.6 feet per Ohm, so that's 5 X 60.6 = 303 feet.

penn71911

Thats great info pamcopete, thanks. I wasn't sure what was under those plugs so I left them alone. Removing that top plate will make it much easier to clean off the residual epoxy.

Retiredgentleman

That's very inventive. The brute force method in lieu of a hydraulic press.

Have a read of this link:
www.650rider.com/index...ght=rewind

It was found to be 325 feet when unwound.

penn71911

Just mic'd the wire, .025 = 22 gauge. Good link RG.

Retiredgentleman

A while back I was interested in the "rotor failure" problem because it was so common. I asked around for a dead rotor just to have a look at the beast. jayel was kind enough to send me one that was "open" circuit.

I hope jayel's not listening, but I found that the coil was only broken at the connection where the coil end is soldered to the front slip ring plate. I re-soldered it and covered it with some epoxy, and now measures about 5.25 ohms, slip ring to slip ring.

pumps

I'll bet he will think you are a fart smeller..I mean smart feller for figuring it out. Wink

If you send your rotor out to...custom rewind? to get rebuilt/rewound what do they charge? I don't recall seeing a price on their site. For my 77 mike charges $139.00 for a new one... $199 for the Stator new also. That makes me want to do the permanent magnet banshee mod. I don't see that mike lists the watt outputs but the aftermarket ones for the banshees I see on ebay go up to 200 watts out put.

xsjohn

The problem with rolling your own stock rotors is getting the ring plate back on once it is all refurbished so it 100% flush.......really need some arangement to spin the rotor and true the face like the factory did......if not the brushes will boggel and they won't last near as long......red loctite on the mating splines......and if the plate comes off it will trash the stator and of course the rotor......and any one that rebuilds them I would hope they true them.....bet they don't......could true the brass slip rings on the bike running with a sharp chisel like a lathe....the brass is a lot thicker that you would think it is......

xsjohn

pamcopete

xsjohn,

No big deal...just chuck it in your lathe and cut it...

pamcopete

RG,

Yea, back in the day when I had an airplane I found the same thing on one of the engines......rebuilt alternators for airplanes were, like....$500, so I soldered it and flew that sucker for another 5 years. Aaah...those were the days!

Check it out!

Petes Airplane

Retiredgentleman

Great looking aircraft Pete! 128 gals for fuel.............that would be expensive for a fill-up.

gordo

That is a nice small plane, Pete. And the price you ask'ed was cheap enough. On that rotor press devise, I think if you drilled a hole & put a 1/2 inch bolt though it,,it would work as a press with an impact gun.You know ,bolt through the center of the rotor with a nut & washer's greased up to slip easier.Thank you RG, that thread is definately informative.Yea, my first & second rotor's did the same thing,burnt the connection's at the slip ring's.Fixed them both once,but the heat that was generated from the bad ground caused internal short's,so replacement was my only option left until now.Thanx to all you guy's.Gordo Cool

weekendrider

penn71911
Good "make do" idea with bolts.

What Happened to 650rider.com?

Yamaha xs650