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Stator DIY rewinding. YVPS 1UA late series

Posted: Sun Nov 12, 2017 12:18 pm
by kjellz
Hi
After frying my stator (as described here viewtopic.php?f=3&t=15095" onclick="window.open(this.href);return false;)
I have started playing With the idea of rewinding the stator myself. After a quick search both here and on Google I think it should be within reach.

Anyway, I found that the charging part of the stator has a somewhat non-symmetrical layout that had me puzzled. That is - it has 14 charging coils where I was expecting to find a factor of 3 number of coils. However the spacing was phase 1,2,3...1,2,3 and so on untill it ended with 1,2 making up a total of 14 coils. I discovered that the number of windings was approximately 40 for each coil and in 3 cases it was only 20 windings/turns on the coi. When I added them all up, I found that phase 1 and 3 had 160 turn totalt distributed through its coils, but phase 2 had 180!?

My initial thoughts was that the total number of windings should have been equal between all three phases, even if the layout is a non-symmetrical distribution.

I am therefore asking you all if I shuold leave it like this - or should I compensate when rewinding and loose 20 turns on phase 2 to make them all 160? Or is there some though behind these from the factory perhaps? Its beyound me for sure at this point, and I have no idea if it has been rewound before.
If anyone has any data to support the number of windings etc I would be pleased to hear it.

Check out my stator disassembly notes inn pptx format here https://1drv.ms/p/s!ArCvt5JQQSh2sxLCkCriNj4_-9SQ

Thanks for reading
Kjell

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Sun Nov 12, 2017 3:26 pm
by whyzee79
RM stator rewinds coils and are very good about technical questions like what you are asking. You might want to give them a call.

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Thu Jan 18, 2018 3:02 pm
by kjellz
I now finished my dyi rewind. Wasn't as bad as first thought.
I decided not be that picky on the total number of windings and replicated roughly the original setup.~40 turn pr core.
The hardest part was to wind it tight enough, and I could clearly not get it as tight as factory.
I plan tp compensate with a generous amount of transformer grade varnish in several coatings.

The ignition coils were left as is.

I got about 0,7-0.8 ohm for each phase when finished. Quite pleased with myself at this stage, but note that this is before testing :smt001
Now I will revert back to some other more mechanical issues to get ready for spring.
Thanks

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Thu Jan 18, 2018 7:34 pm
by hondaror
You are an absolute animal for attempting this...kudos. Interested in knowing if it works.
More windings = more voltage, not sure about amperage though.

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Thu Jan 18, 2018 9:47 pm
by JonW
I agree with Rory, what a great thing to do yourself. Im keen to know how this works out, it sounds like we might all be doing this soon as the price of wire is cheap enough compared to the cost of a Pro rewind.

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Fri Jan 19, 2018 8:24 am
by MK
There's good chance that it'll work.
People in Germany did that in the past and if you compensate the weak point (aka epoxy the loose windings) it should do the job.

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Mon May 21, 2018 4:37 pm
by kjellz
Update:
- finally installed the diy stator and checked charging. At 1500 rpm I got 12.9 V and 14.5V at 5k rpm. Both measured at the battery terminals with headlights on. Pretty happy with that :-)

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Mon May 21, 2018 7:46 pm
by JonW
Pleased to hear this. What a great project.

Can I ask where you got the wire and if it came lacquered or you did that prior to winding?

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Tue May 22, 2018 4:10 am
by hondaror
That is so cool. Fill us in with more info. Great job!

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Tue May 22, 2018 7:10 am
by kjellz
The wire must be a coated type. I got this one of ebay: https://m.ebay.com/itm/0-95mm-ENAMELLED ... xyffZSZ5MN" onclick="window.open(this.href);return false; . Note to measure your wire thickness of your old stator after carefully scraping of the varnish. Additional varnish to seal off and secure everything when done;
https://m.ebay.com/itm/RED-AIR-DRYING-V ... xy4fVS--hM" onclick="window.open(this.href);return false;
Be careful with the fumes from the varnish. Read the leaflet!

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Tue May 22, 2018 9:51 am
by JonW
Thats superb Thanks!

Do the wire thicknesses differ on the stator, or do you mean some models of stator might have a different thickness?

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Tue May 22, 2018 10:02 am
by JonW
One other question: Why didnt you do the ignition coils at the same time?

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Tue May 22, 2018 10:29 am
by kjellz
Hi
I am just saying I do not know what exact wire dim was originally used, nor do I know what the different stator versions used. I found 0.95mm to be closest to the ones I peeled off the charge coils. The ignition coils were left as was, as they tested good and were not burnt and they may be different dim than charge coils as well. I am guessing ignition coils are subject to less stress than charge coils?
Anyway the whole thing was a first for me so I decided to limit this to charge coils...this time.

Still, only time and accumulated kilometers can be the final judge of success ?

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Tue May 22, 2018 7:31 pm
by JonW
Thanks, thats all wonderful info. Really appreciate it and might well give it a go.

One last question: how much wire did you use all up?

Re: Stator DIY rewinding. YVPS 1UA late series

Posted: Wed May 23, 2018 4:15 am
by kjellz
You will need approximately 30 meters of wire for the charge coils. See details and notes here on slide 2 https://1drv.ms/p/s!ArCvt5JQQSh2sxLCkCriNj4_-9SQ" onclick="window.open(this.href);return false;

Let me know if the link should not work.

Cheers
Kjell