Caltric Stator-no coating on stator windings?

[Carter Turk]

Bought one awhile ago. It's on my 1150ES.

The windings had no coating on them which I thought was odd, but for $40 I wasn't expecting much.
Was I supposed to coat the windings with something before running it? Or run as is, which I did.
The copper windings around the poles looked kind of sloppy/loose.

I've rode the bike several times, but haven't gone on any really long rides yet.

 

[Cipher]

they had to be coated or else their would have been a short circuit.

 

[Nessism]

The winding varnish/sealer is to keep the wires from vibrating against one another and wearing away the coating on the wire and shorting. No varnish suggests the stator might not be as durable as otherwise would be the case. Hopefully you get at least your money's worth from it.

BTW, where I work we purchase motor stators, among other parts, and the varnish is applied using a vacuum system to assure the varnish is pulled deep into the windings. The varnish is quite thin and you can't hardly see it, contrary to what you see on some motorcycle stators.

 

[posplayr]

The winding varnish/sealer is to keep the wires from vibrating against one another and wearing away the coating on the wire and shorting. No varnish suggests the stator might not be as durable as otherwise would be the case. Hopefully you get at least your money's worth from it.

BTW, where I work we purchase motor stators, among other parts, and the varnish is applied using a vacuum system to assure the varnish is pulled deep into the windings. The varnish is quite thin and you can't hardly see it, contrary to what you see on some motorcycle stators.

All true, but the dominate force on each winding is that of electromagnetic force which generates the current in the coils. Along with vibrational forces, electromagnetic forces must be constrained using tight windings and a coating of high temperature epoxy to immobilize and movement of the winding. The immobilizations minimizes work hardening and "rubbing" that might lead to shorts and opens.

 

[Nessism]

All true, but the dominate force on each winding is that of electromagnetic force which generates the current in the coils. Along with vibrational forces, electromagnetic forces must be constrained using tight windings and a coating of high temperature epoxy to immobilize and movement of the winding. The immobilizations minimizes work hardening and "rubbing" that might lead to shorts and opens.

What happens to the windings as a result of these electromagnetic forces? Do they move and vibrate by chance as a result?

 

[posplayr]

What happens to the windings as a result of these electromagnetic forces? Do they move and vibrate by chance as a result?

Maxwell's equation define the forces on a wire that moves through a magnetic field.

The normal engine vibration is from the synchronous explosions that occur in the combustion chambers.

The electromagnetic forces are direct to the wire. The vibration is through the inertia of the crank,engine and even the mass of the motorcycle floating on rubber contact patches.

Imagine a big monster picking up your bike and trying to shake loose the windings of the stator.

In contrast, the electromagnetic forces are related to the energy produced which is approaching 1 hp (especially for Shunt R/R), but less for Series R/Rs.

 

[Nessism]

Jim,
The varnish is to keep the wires from moving (vibrating) against one other. The mechanism creating the relative movement (vibration) can be mechanical, electromechanical, whatever.

 

[posplayr]

Jim,
The varnish is to keep the wires from moving (vibrating) against one other. The mechanism creating the relative movement (vibration) can be mechanical, electromechanical, whatever.

The epoxy is to keep the windings from moving at all. If the ductile copper is allowed to flex, it will work harden causing the wire to break even if there is no relative motion of windings.

If you take a piece of steel and bend it within limited range of stress it will operate practically forever.
If you take a ductile piece of metal such as copper and bend it over a similar range it will fail much quicker through the process know as "work hardening".

https://en.wikipedia.org/wiki/Work_hardening

 

[Sandy]

Next time you.have it apart I don't see any reason you can't give it coating of epoxy or something similar. I'm sure there's a product out there for that purpose. Maybe Jim knows of something.

 

[posplayr]

Next time you.have it apart I don't see any reason you can't give it coating of epoxy or something similar. I'm sure there's a product out there for that purpose. Maybe Jim knows of something.

I would defer to the manufacturers that know how to do it. See Electrosport.

 

[Carter Turk]

So... the consensus is there was supposed to be a coating?
Opened a nice Caltric box, stator inside with copper wound around the poles and three holes to mount, three wires... That's it.
I bought this less expensive version due to positive reviews on this forum.
Never noticed a mention of having to do anything to the stator after purchase aside from mounting it up.

 

[Sandy]

So... the consensus is there was supposed to be a coating?
Opened a nice Caltric box, stator inside with copper wound around the poles and three holes to mount, three wires... That's it.
I bought this less expensive version due to positive reviews on this forum.
Never noticed a mention of having to do anything to the stator after purchase aside from mounting it up.

Here's a photo of a new one I have on the shelf for my 750. It's unmarked so I'm not sure if it's original Suzuki or aftermarket but the windings are coated with a white epoxy type coating on the exposed ends on both sides. It appears to be just brushed on. Perhaps contact a local electrical shop that does rewinding and maybe they have something you can put on. It would have to be both heat and chemical (oil) resistant


by soates50, on Flickr

 

[tom203]

"Never noticed a mention of having to do anything to the stator after purchase aside from mounting it up."

just mount it and stop fretting... You don't need blue/green/ goop over it,unless you are covering up a poor winding job.

 

[posplayr]

"Never noticed a mention of having to do anything to the stator after purchase aside from mounting it up."

just mount it and stop fretting... You don't need blue/green/ goop over it,unless you are covering up a poor winding job.

Agree that the stator is what it is and while it may not be the best it is serviceable as is. The likelihood of trying to successfully improve it are pretty low.

 

[Carter Turk]

"Never noticed a mention of having to do anything to the stator after purchase aside from mounting it up."

just mount it and stop fretting... You don't need blue/green/ goop over it,unless you are covering up a poor winding job.

Not fretting, merely noticing all the other stators I've had were coated.
Why the coat if it's not neccessary?
I'll admit the lack of coating made me question whether it would work or not, but it's been mounted up for months.
Thought I'd check and see what you folks had to say about it, is all.

 

[duaneage]

A caltric stator failed in my 650 because the lacquer came off the windings. The oil shorted it. I measured the resistance with it dry on the bench and when I poured oil on it a short developed.

 

[Carter Turk]

Hmmm, so some fretting then?

 

[Sandy]

A caltric stator failed in my 650 because the lacquer came off the windings. The oil shorted it. I measured the resistance with it dry on the bench and when I poured oil on it a short developed.

Vibration chafed through the lacquer perhaps???

 

[duaneage]

Nope the coating came off easily. Looked like either the oil attacked it or the wire wasn't prepped before coating. I put an electrosport in because it had superior coating on the wire. The caltric wires were not extra dipped. It's in 220 degree oil so it needs protection.
All the other stuff about magnetic and vibrations didn't apply.

 

[duaneage]

The funny thing about the failure was when the bike sat for 4 days it would charge normally upon starting. As soon as enough oil worked it's way around it the charge went down. I knew it was a problem with insulation somewhere. I got 6 years out of my 80.00 so I was ok with it. Things happen.