Stator Rewrap

[gm280]

I see progress and it looks interesting. I see you are using a fly tying spool setup to feed out the magnet wire and keep it straight. Good idea. You may want to check out some guitar pickup builds and see how they keep track and wind pickups. It seem like very similar work. Keep posting. :thumb:

 

[Pusher]

Thanks GM, I'll look into that!

 

[Pusher]

Break time

 

[gm280]

Ha Ha, that is starting to look like a wound stator. Looks pretty good Pusher. I think you got it now. :thumb:

 

[Pusher]

No spark at the plugs. I'm producing 3 volts from the LS coil while it's cranking. I have a suspicion that the battery was undercharged so it's on the trickle charger now.

I have 15 ohms of resistance between the ground and red wire (ls) and 59 between ground and blue (hs).

Also, I disconnected what I believe to be the kill switch which is the black wire in the upper right by the starter.

Time to research the CDI material while it charges.

Oh yeah, yellow leads were looking good also.

 

[Pusher]

My wraps were grounding out so I rewrapped everything. The Low Speed is putting out .9 volts like it is groundig out somewhere but the High Speed wrap is doing 13 volts.
I tried putting the High Speed coil on the low speed switch box post (red). The voltage coming out to the spark plugs is .8 and the ignition coil input is .8 I believe.

Any thoughts on the coils or if the swotch box is bad?

 

[gm280]

With the low speed coil totally disconnected from anything, do you get any voltage out. And have you run a resistance test from the low speed output wires to the ground. If so what did you read. If you read anything, then you still have a short somewhere in the low speed windings. But if it read open, like it should, then you have something other then the low speed windings as your problem. JMHO

 

[Pusher]

The low-speed and high-speed wires are all one continuous circuit. The black ground starts the wraps on the low speed which is finished by the red wire and then the high speed starts at the red wire and wraps to the blue.

Oh I forgot to mention, my voltmeter reads (NEGATIVE) 13 volts when cranking. Probably an important detail huh?

 

[Faztbullet]

You should have a min of 25VAC on red to ground and min of 180VAC on blue to ground when cranking....

 

[Pusher]

Well, I think this is the end of the road for me. It's been a fairly fun learning experiment but I don't think the math works.
Having thicker wire means you have to get more wraps in each post to generate the same voltage.
I purchased 30 gauge wire, which is pretty small. The stuff that was on it before was as thin as a hair and likely spun with other strands for strength.

I found 42 gauge wire for $15 online... I don't know if I have it in me though.

Final thoughts?

 

[gm280]

Well, I think this is the end of the road for me. It's been a fairly fun learning experiment but I don't think the math works.
Having thicker wire means you have to get more wraps in each post to generate the same voltage.
I purchased 30 gauge wire, which is pretty small. The stuff that was on it before was as thin as a hair and likely spun with other strands for strength.

I found 42 gauge wire for $15 online... I don't know if I have it in me though.

Final thoughts?

Pusher, did you actually measure the original gauge wire? And if so did you also count the number of windings on the original. Even if you go with a large size (smaller gauge ) wire, you still have to wind the same number of wraps. It is the number of winds that determine the voltage output, not the gauge. The larger gauge can only carry more current. If you wrapped the coils in the same directions as the original and with the same number of turns, it should work. There is nothing else to keep it from working. Basically it is the exact same technique used when winding transformers as well. JMHO

I say don't give up. If you are thoroughly disgusted, put it away for a while and come back to it at some later date. Because to just give up will haunt you later on. JMHO

 

[Pusher]

I ordered 42 gauge wire last night

It wasn't possible to count the number of wraps as it was a fused bundle of plastic and weak stands. I measured the outside width of the original coils and wrapped a little wider to compensate for loser wraps and large wire.

I just don't understand why the low speed wouldn't produce power. I might remove the terminals and measure of the bare wire tonight and see if it was a bad connection. Otherwise I hope I'm not doomed to repeat my failures.

Want to visit washington state and help GM?

 

[gm280]

I ordered 42 gauge wire last night

It wasn't possible to count the number of wraps as it was a fused bundle of plastic and weak stands. I measured the outside width of the original coils and wrapped a little wider to compensate for loser wraps and large wire.

I just don't understand why the low speed wouldn't produce power. I might remove the terminals and measure of the bare wire tonight and see if it was a bad connection. Otherwise I hope I'm not doomed to repeat my failures.

Want to visit washington state and help GM?

Honestly Pusher, if I could I certainly would. I like projects like yours. But remember, if you don't succeed the first time, don't repeat the same procedures or operations, or you will get the same results. Something has to change. Now knowing you didn't replace the same number of windings as original, it make a lot more sense to me. I sure wish you would have counted the original number of wraps. Now it is merely guess work. You could wind just one coil and install the stator with those wires coming out and read them for output voltage. Then adjust the windings until you get it to where it has to be. Then wrap the others to that same number of wraps. Just an idea. There is one other way to determine the umber of windings. But that would mean you meed to know the total resistance of all of the low speed and high speed windings of a good stator. And you would also need to know the exact gauge of the original windings. Then you can use a typical table that shows the resistance per 1000 feet of each copper gauge wire and do the math.

Example, 32 gauge copper wire has a resistance of 164.1 ohms per 1000 ft. So if you read the resistance across a good stator and it is 82 ohms (I choose that for simplification) then you know a total of 500 feet of 32 gauge wire was used. Then divide that by the number of pole you are winding and that will tell you the length of wire wrapped around each pole/coil. And there you have it. But you need both the total resistance and actual wire gauge from a good unit. JMHO

 

[Pusher]

That makes sense. Unfortunately, there was zero chance of counting the wraps even if I had 10 more to try it on. If the 42 gauge wire is the same diameter maybe I could test the resistance after "spooling up" and compare to CDI's specs... Assuming they use the same gauge as the OEM. I'd just have to soldier and epoxy and extebsion on if it wasn't right. If the strands match though, I feel confident in wrapping to the right diameter within "tolerances".

The stator coils are fused to the plastic they encapsulte them in... And then melting it off compounds the problem, so the number of wraps remains a mystery know only by the OEM and CDI :-/
(Insert mystic wizard emoji here)

Thanks for reminding me about the definition of crazy. I need to figure out why one post gets less than one volt and the other with twice the wraps get 15 times the volts. There's a gremlin somewhere.

In other news, my brother picked up a running 50hp evinrude from the 70's for $400. Christmas shopping is done for this guy!

 

[Pusher]

Page 81 of this manual (83 of the pdf) shows LS coil should read 160 ohms and the HS coil should be 7000. How's it possible to go up like that? Do you think the LS is using braided strands and the HS isnt? The HS is about twice the LS diameter so I was guess it would be 3 times the ohms... Using dirty math without any science.

I bet everyone's sick of seeing this thread show up in the feed.

 

[Pusher]

And I meant twice the diameter of total wraps not twice the diameter of wire gauge.

 

[Pusher]

But remember, if you don't succeed the first time, don't repeat the same procedures or operations, or you will get the same results. Something has to change.

Example, 32 gauge copper wire has a resistance of 164.1 ohms per 1000 ft. So if you read the resistance across a good stator and it is 82 ohms (I choose that for simplification) then you know a total of 500 feet of 32 gauge wire was used. Then divide that by the number of pole you are winding and that will tell you the length of wire
JMHO

Tomorrow.... I shop.

 

[StarTed]

Just read some of your project and it interests me.

We used to make precision insturment transformers where I worked. Most of that work was done during the WWII era but the skills still existed when I came there.

The turns are critical since the formula is turns per volt. The wire gauge comes into play for current handling so it needs to be large enough to handle the current but small enough to fit into the space available. You need magnet wire which I have some sizes.

Another thing we used was Glyptol to encapsulate the varnished wire. It needed to be baked to cure it properly. This was done in a regular kitchen oven. I suppose epoxy would work but no movement is acceptable since that'll compromise the varnish insulation. The encapsulation material can't attack or break down the original insulation or it'll fail.

I'm not sure your bodkin used for winding might not scratch the wire while winding.

We used a South Bend lathe with a revolution counter connected to the headstock to get the exact number of turns. If you have a small Unimat or watchmaker's lathe that should work fine.

I'm in Eastern Washington so PM me if you're in the area.

 

[Pusher]

I believe that CDI Electronics no longer epoxys their stators... Or soe rumor says. I don't like that ideo so I'm at least going to use epoxy.


You are corrdct about the bobbin. The first try ended up shredding the shielding off. The second attempt I spread the spool keep wide enough to reduce almost all tension. That seemed to work. This time though I'm doing straight gloves, no bobbbin.

I could use your thoughts on a thread counter. How could I hook one up to a sewing machine or threaded rod? I'm planning on dumping overkill onto the coil then measure resistance and unwind from that.


I live in Yakima, are you down by the Tri Cities?

 

[StarTed]

My information was about winding transformers for 60Hz so the number of turns is critical. In your case the numbers should be the same for all of them I think so a revolution counter would be beneficial. Voltage should vary with number of turns and frequency (RPM)

I think I have some counters around here. Just don't know where at the moment.

I think your use of gloves should be a good one.

I live south of Cheney so we're a few hours apart. I do believe an old sewing machine motor turning some kind of chuck through a speed reduction could work satisfactorily. I once made a fishing rod winder that way.

I'll be visiting the Royal City area in a little over a week. Maybe I could come up with some kind of winder in the meantime.

Let me know if you're still interested.