# Coil Field issue



## Aseelow (Jan 27, 2019)

Hey everyone, perhaps this has been covered, perhaps not. I did a search and since I have a specific question I thought it would be easier just to ask it in a new thread. 

I have an 293 steam engine that didn't run. It would just hum and the armature looked like it would want to move, but wouldn't. Then I would get a small wisp of smoke, and I'd shut it off. After trouble shooting with some parts from another engine, a 301, I found that if I just used the coil field from the 301 on the 293, it worked great. The wires on the bad coil field from the 293 look intact, but I'm no expert. Could there be a broken wire underneath? Is it worth trying to fix, or should I just get a new/used one off ebay? 

Thanks for the help...again. 

Adam


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## dooper (Nov 9, 2015)

Since no one else has replied as of yet, I will. Did you mean 301 instead of 201, AF did not make a post war 201 (if they ever did). 
The problem I have most encountered with fields is that the bottom wire breaks off and a piece of it can not be obtained without unwinding all the wire. Have you checked the continuity of the 293 field?

There are many part suppliers out there that may be less expensive than ebay. 

Al


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## cramden (Oct 13, 2015)

Dooper is correct, its usually the field underneath. Check resistance for each field. It should be 1 to 2 ohms. If you don't get that reading then a wire is broke. It can be re-wound but its easier to just replace it. You can get them on ebay but I would get them from Portlines.com. He sells used, re-wound and NOS. fields. Better that, then hoping to get a good one on ebay IMO.


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## AmFlyer (Mar 16, 2012)

You want the XA-9547 field. DC resistance as measured with an ohm meter) is 1.2 to 1.4 ohms.


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## Aseelow (Jan 27, 2019)

Dooper, you were right, I meant 301. I changed it in the original. Thanks. 
And thanks or the tip of shopping around for parts. I'll keep that in mind. 

I'll check resistance and see what I find. Thank you for the numbers to look for. Very helpful. 

Adam


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## mopac (Feb 24, 2011)

I had a broken bottom wire. Only way was to take all wire off. I rewound it by hand.
Could not get the last 12 feet of wire on because I could not wind as neat as Gilbert could.
It works fine. I have other coils and still use this one.

That's a great way to trouble shoot a problem. Change parts one at a time till fixed. 
My 282 ran at about half speed and motor got really hot. I bet I took that thing apart 25
times over a 40 year period. I finally bought a parts engine and started changing parts.
Got to the armature and it was finally fixed. Had a bad armature. Its a hot rod now and runs cool.


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## mopac (Feb 24, 2011)

If you find a broken wire and want to rewind the wire yourself when you go to solder the wire ends you have to sandpaper the 2 wire ends. The wire is covered in shellac or plastic. Get it down to the wire.


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## flyernut (Oct 31, 2010)

Just pull the wire off and re-wind it. I've done this and it's not too bad..And like the others have stated, check the continuity of the coil.


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## mopac (Feb 24, 2011)

Funny thing on my bad armature. It checked out fine on the multimeter between 
all three sections. Had correct readings but it was bad. Still have the bad armature
but it is in a plastic bag marked BAD.

I found a web site on a business that rewinds bad AF armatures. Can't remember name of the place.
On the site they described symptoms of a bad armature, it was exactly what mine was doing. I called
them to get a price and they never called me back. This was before I bought the parts engine so I
did suspect a bad armature.


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## [email protected] (Mar 8, 2019)

I agree winding that field should not be difficult...provided you can get the insulated/ shellac coated wire for a reasonable price. Count the # of windings and get as close as you can on the rewind.


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## AmFlyer (Mar 16, 2012)

You need 24 gauge wire. The steamer fields had between 187 and 206 turns on them. I have never rewound one but it might be possible to reuse the original wire.


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## flyernut (Oct 31, 2010)

AmFlyer said:


> You need 24 gauge wire. The steamer fields had between 187 and 206 turns on them. I have never rewound one but it might be possible to reuse the original wire.


That's a possibility, depending on where the suspected break could be..


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## dooper (Nov 9, 2015)

As mopac did, I also rewound a field with the original wire, and, suprise, it did work.

Thinking aloud here, how could a wire in the middle of the field break? If it is not moving it usually does not break.

Aseelow, let us know what you find.
Al


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## mopac (Feb 24, 2011)

The engine I used in the video with the open air resistor is the coil I rewound with original wire. As you can see it runs great. Even with 12 feet of wire missing. It was not that bad of a job. Make sure armature can turn without hitting the wire. That's why I had to cut some off. I had most on but armature was hitting the wire. As you wind keep wire tight and lay a loop beside previous loop.


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