Stator; Buy new, or rewire by hand?

[sutor623]

This is a question that I had when I first discovered this:

You can see by my left hand, some of the poles were completely fried. Stator was barely charging, and new ones for this motor are NLA. If you cant find one on ebay you can send out the core and get it rewired for over $200. Crazy.

 

[sutor623]

Re: Stator; Buy new, or rewire by hand?

Anyways, I figured out that the wire is 20G annealed (magnet) wire. I used scotch 27 high heat glass tape for insulation. You can see how the nylon insulation was burned. I decided that the best way to replicate the winding was to put some tape over the old nylon, that way the nylon will still help to keep the wire in place during vibration.

 

[sutor623]

Re: Stator; Buy new, or rewire by hand?

So then after I made sure insulation was in check, I tightly wrapped the wires in the same direction, and the same number of coils on each pole. It looked brand new when it was done, and cost me around $30 in parts. Now I still have enough wire to rewire the stator 2 more times. So it is a win-win as far as I'm concerned.

And finally, installed onto the motor.

 

[sutor623]

Re: Stator; Buy new, or rewire by hand?

I checked the resistance from both ends of wire, and it was .4-.6 just as it is from the factory. Voltage at battery was 13V at idle, and 13.5V at around 1500RPMs. I am siked to get out on the water and give this guy the real test!!

 

[jhebert]

Re: Stator; Buy new, or rewire by hand?

Thanks for posting these interesting pictures along with your narrative of the repair of your permanent magnet alternator stator. Give us the on-the-water test results, too.

Your ingenuity in making a repair like this is to be admired. This sort of resourcefulness seems rare these days in the USA. We tend to throw too much material away instead of just fixing it.

 

[sutor623]

Re: Stator; Buy new, or rewire by hand?

Thanks for posting these interesting pictures along with your narrative of the repair of your permanent magnet alternator stator. Give us the on-the-water test results, too.

You ingenuity in making a repair like this is to be admired. This sort of resourcefulness seems rare these days in the USA. We tend to throw too much material away instead of just fixing it.

Thanks jhebert!! I am happy that you appreciate this. I feel the same way. I hoped this would help people in the future!

 

[coastalrichard]

Re: Stator; Buy new, or rewire by hand?

Thanks jhebert!! I am happy that you appreciate this. I feel the same way. I hoped this would help people in the future!

Yeah...great thread sutor...now I know where to send my next fried stator for repair. Please post some water pics

 

[sutor623]

Re: Stator; Buy new, or rewire by hand?

Yeah...great thread sutor...now I know where to send my next fried stator for repair. Please post some water pics

Will do!! I have gotten so much great advice from all of you, that I like to give back when I can. I will more than likely pull the flywheel in 5-10 hours just to make sure the wires have stayed put. An electrical engineer that I was getting some info from on a different forum told me that the problem that you can have, is the wire vibrating and rubbing the insulation off of the individual wires. This causes shorts amongst the wire itself, creating heat, which then fries the insulation, and then the stator winding shorts out on the armature itself. From what I have learned, a problematic rectifier will cause the stator to overheat as well. A very cost effective fix, especially when your motor is older than you are and parts are NLA!

 

[sutor623]

Re: Stator; Buy new, or rewire by hand?

Yeah...great thread sutor...now I know where to send my next fried stator for repair. Please post some water pics

Will do!! I have gotten so much great advice from all of you, that I like to give back when I can. I will more than likely pull the flywheel in 5-10 hours just to make sure the wires have stayed put. An electrical engineer that I was getting some info from on a different forum told me that the problem that you can have, is the wire vibrating and rubbing the insulation off of the individual wires. This causes shorts amongst the wire itself, creating heat, which then fries the insulation, and then the stator winding shorts out on the armature itself. From what I have learned, a problematic rectifier will cause the stator to overheat as well. A very cost effective fix, especially when your motor is older than you are and parts are NLA!

 

[Fishsqueezer]

Re: Stator; Buy new, or rewire by hand?

This is great info. I just replaced the stator on my Mariner 50 hp, and the factory unit was encased in plastic. However, the one I purchased was not and when it fails, I'll give this a try myself.

@ jhebert: I couldn't agree with you more. Throwing away repairable items seems to be the norm, unfortunately.

 

[sutor623]

Re: Stator; Buy new, or rewire by hand?

Well that plastic is designed to keep the wires tight and prevent vibration. You can always paint on a few layers of varnish to each pole if you wanted to. It is not entirely necessary to do so though. I would imagine that you will get many hours out of your new stator. It doesn't hurt to add a volt meter to you system just to see how well the battery is charging. That way you can catch a failing stator before it takes out some other electrical components.

 

[minuteman62-64]

Re: Stator; Buy new, or rewire by hand?

Hey, a throwback to the old days, when mechanics actually repaired things, instead of simply replacing parts. My dad was a mechanic from the 30's to the 70's and when he began his career he would repair generators and starter motors by rewinding coils.

 

[jhebert]

Re: Stator; Buy new, or rewire by hand?

I have published a photograph of a permanent magnet stator. See

http://continuouswave.com/whaler/reference/PMA.html

The photograph shows a new, replacement OEM stator. Notice that the windings at each pole are not painted or covered with a coil dope. It was typical in the past for windings like this to be covered with a coil dope, but I believe that this practice has been abandoned, at least it has with this supplier. I do notice there is a glob of some sort of gel or putty on each winding to fix the turns in place.

Also, I see you followed the original stator winding by reversing the phase with each pole. This is an important detail to follow.

 

[sutor623]

Re: Stator; Buy new, or rewire by hand?

Yeah I have seen them both ways.

 

[sutor623]

Re: Stator; Buy new, or rewire by hand?

Ok guys a little update. I have been on the water twice now. Ran the bilge pump a few times, had the lights on at night, and never turned the fishfinder off. Fished 10-20 spots, so I started the motor 10-20 times or more. Took the battery home and threw it on the charger, and it said full charge both times. So real life testing has shown that the hand-wound stator is definitely doing its job.

 

[bashr52]

Re: Stator; Buy new, or rewire by hand?

Awesome work! Where did you get the tape and wire from?

I know it is possible to get a stator re-wound for a higher output, I did so on my 4-wheeler. Would it be possible to add a couple more turns on each pole and acheive the same result?

 

[sutor623]

Re: Stator; Buy new, or rewire by hand?

Awesome work! Where did you get the tape and wire from?

I know it is possible to get a stator re-wound for a higher output, I did so on my 4-wheeler. Would it be possible to add a couple more turns on each pole and acheive the same result?

Got the 3m tape and wire off ebay. I am not so sure about adding turns to get a higher output. I would talk to Jim Hardy on PhysicsForums.com. He seems to have great input on all things of this sort.