How to Destroy a freshly rebuild Magneto Coil Ring.

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Model T Ford Forum: Forum 2017: How to Destroy a freshly rebuild Magneto Coil Ring.
Top of pagePrevious messageNext messageBottom of page Link to this message  By Andre Valkenaers on Tuesday, April 04, 2017 - 07:04 am:

Hi All just for information.

A few weeks ago A car arrived with the magneto not working. After a few test, the engine was taken out of the car and disassembled. The coil ring was set on a stand and tested on polarity with a 12V battery without using a light bulb in the circuit.
This what happened:

Then we looked for the reason. Here is what we found:


The magneto stopped working because the band parts between the coil connections and the magneto frame making a short.

Andre
Belgium


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stephen, South Texas on Tuesday, April 04, 2017 - 07:13 am:

Bands? Was the owner using steel wool bands? I don't understand.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Andre Valkenaers on Tuesday, April 04, 2017 - 07:17 am:

Kevlar and oil ?????


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Smith, Lomita, California on Tuesday, April 04, 2017 - 09:20 am:

I destroyed mine by having a funnel on my oil tube come loose. Wiped it out!


Top of pagePrevious messageNext messageBottom of page Link to this message  By john kuehn on Tuesday, April 04, 2017 - 09:26 am:

It looks like steel wool to me. But maybe metal shavings? If the engine was rebuilt was the block cleaned up good enough after machining? Or small slivers of Babbitt?

Whatever it is it got into the engine and got into the mag ring and shorted out the coils against the mag ring frame.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Andre Valkenaers on Tuesday, April 04, 2017 - 09:38 am:

Car and engine were rebuild about two years ago. Magneto worked fine for about 5 months and suddenly stopped. The car was driven on battery since for two years.
I didn't do the rebuild and I don't know by who and how it was done and cleaned.

I think the dirt between the coil strap is Kevlar, oil and small metal parts.
I will take the bad coil out of the ring, clean it and take it apart for a check and rebuild it.

Just what I think

Andre
Belgium


Top of pagePrevious messageNext messageBottom of page Link to this message  By Keith Townsend ; ^ ) Gresham, Orygun on Tuesday, April 04, 2017 - 09:39 am:

Andre'
In the top photo it looks like there is some metal missing of the iron of the ring frame where it mounts to the block. Maybe that is the source of the metal? Either ground away on purpose, or something rubbing inside?

It looks like it should be a relatively easy fix.

: ^ )


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Tuesday, April 04, 2017 - 11:58 am:

From my inspection of the pictures attached, that looks like a double stack coil. It is quite possible that the end of the copper winding at that point was too close to the frame. Perhaps a piece of band lining was flung against it causing it to touch the metal frame. You might be able to rewind that individual coil with new insulation and re-install it and solder it with a very large iron saving the coil ring and other coils.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Tuesday, April 04, 2017 - 12:00 pm:

From my inspection of the pictures attached, that looks like a double stack coil. It is quite possible that the end of the copper winding at that point was too close to the frame. Perhaps a piece of band lining was flung against it causing it to touch the metal frame. You might be able to rewind that individual coil with new insulation and re-install it and solder it with a very large iron saving the coil ring and other coils.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Wayne Sheldon, Grass Valley, CA on Tuesday, April 04, 2017 - 03:20 pm:

Graphite in the oil? Not specifically graphite, but a conductive powder and some sort of cloth/thread material is how suppression wires and light bulb filaments are made. A graphite oil and band lining (cotton or Kevlar) material could do that. Especially if there was even a tiny amount of iron shavings mixed in.
Generally, iron shavings won't cause a short in that way because the magnets on the flywheel attract and hold all the iron particles far enough away from potential electrical pathways. If there are a large enough amount of iron shavings, or even just a few mixed with another conductor (like graphite), it could happen.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jack Putnam, Bluffton, Ohio on Tuesday, April 04, 2017 - 05:38 pm:

That individual coil may be usable as is and does not need to be rewound. The short was externally of the coil itself. In the literature there is a topic of "burning" the shorts in the mag coil. That is what you did to locate your short. Remove the debris and recheck the integrity of the coil.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Phil Mino, near Porterville on Tuesday, April 04, 2017 - 05:54 pm:

The coil frame appears to have a minimal coating of whatever was used on the individual coils themselves.

Note that these originals have a rather liberal (thick) coating of the insulating varnish all over the frame and coils.

The late one also has a layer of thick paper behind the individual coils thus insulating them further from the frame.

10 coil -1

10 coil -2

10 coil -3

mag coil -1

mag coil -2


Top of pagePrevious messageNext messageBottom of page Link to this message  By Andre Valkenaers on Wednesday, April 05, 2017 - 01:17 am:

Thank you all for your input.
I share the meaning of Wayne for the reason and the way it happened. I will try to repair the burned coil the way Norm said.
First the ring will be cleaned, the repair done and at last the total will get a double coating of polyester resin as I do usually with my other coil ring rebuild.

Andre
Belgium


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jim Patrick in Florida on Wednesday, April 05, 2017 - 01:29 am:

Walter Szumowski told me he coats his completed coil rings with Glyptal. I used red Glyptal to coat the inside of my engine in 2010. The reflective properties makes it much easier to see inside the crankcase. Jim Patrick


Top of pagePrevious messageNext messageBottom of page Link to this message  By Andre Valkenaers on Wednesday, April 05, 2017 - 03:56 am:

Jim,
You are right about the Glyptal.
I use Polyester resin for two reasons:
- Glyptal is hard to find here.
- With the polyester resin I fill up all the corners and gaps in the coil ring so the band residue will not get trapped between it.

Andre
Belgium


Top of pagePrevious messageNext messageBottom of page Link to this message  By Andre Valkenaers on Thursday, April 13, 2017 - 06:52 am:

Coil ring repaired. I had to rebuild the burned coil. During the cleaning I found a solder residue between the copper rope and the coil.
After the reassembling I checked the loop on polarity. The alternating of North and South was just as it should be. The coil ring loop should work well.
To test the polarity I made an electric circuit with a 12V battery a 21W 12V light and the coil ring. The polarity was tested with a compass.

Andre
Belgium


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Thursday, April 13, 2017 - 09:48 am:

Glad you were able to repair it. :-)


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