Why aren't the coils in electric motors insulated?

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  • #1
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In all the electric motors I have taken apart, the coils on the armature have never been insulated. This has always confused me because, how could the coil make a sufficient magnetic field if it shorts out to the adjacent wires from lack of insulation?
 

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  • #2
DaveC426913
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Are you sure they're not coated in a thin layer of clear sheathing?
 
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  • #3
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Are you sure they're not coated in a thin layer of clear sheathing?

I have suspected that but I do not know for sure. I was wondering if anyone else could confirm. :]
 
  • #4
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They are insulated with a thin transparent layer of insulator.
 
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  • #5
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They are insulated with a think transparent layer of insulator.

No, I don't think it's transparent.

Magnet wire is coated with a thin layer of enamel. The color is usually gold, making it appear similar to bare copper. It also comes in other colors, such as red and green.
 
  • #6
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Cool thanks guys!
 
  • #7
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No, I don't think it's transparent.

Magnet wire is coated with a thin layer of enamel. The color is usually gold, making it appear similar to bare copper. It also comes in other colors, such as red and green.

Thanks a lot. Do you know how to remove the insulation before soldering? Or is it removed by the heat while soldering? I usually use flame to remove the insulation first. Sometimes just scratching them by a knife! I wonder if there was a more efficient way.
 
  • #8
DaveC426913
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Thanks a lot. Do you know how to remove the insulation before soldering? Or is it removed by the heat while soldering? I usually use flame to remove the insulation first. Sometimes just scratching them by a knife! I wonder if there was a more efficient way.

Wire strippers are the correct way.
 
  • #9
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Thanks a lot. Do you know how to remove the insulation before soldering? Or is it removed by the heat while soldering? I usually use flame to remove the insulation first. Sometimes just scratching them by a knife! I wonder if there was a more efficient way.

Yes, there is a more efficient way. You can buy a machine that is designed for removing the insulation. However, the price is probably too high for the hobbyest. I used such a machine many years ago when I worked for a motor manufacturer. At home I usually just lay it on a flat hard surface and scrape it with a sharp knife. I've never had much luck with using wire strippers on magnet wire.
 
  • #10
Pengwuino
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Wire strippers are the correct way.

How do you use wire strippers to take off such a thing layer?
 
  • #11
DaveC426913
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How do you use wire strippers to take off such a thing layer?

Mm. Good point. It's not designed to be stripped like regular electrical wire, is it? It won't just slide off.
 
  • #12
AlephZero
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Modern "enamelled" wire usually has a plastic coating that will burn off cleanly during soldering. The wire in old motors etc uses "real" enamel which needs to be scraped off with a knife blade or fine sandpaper.

There are electrically powered tools available to do this on an "industrial" scale.
 
  • #13
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Apparently some types of enamel could be stripped by placing the wire on aspirin tablet and heating with a soldering iron (or so the urban legend says). Never tried it myself though.
 
  • #14
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Use a pocket knife and scrap off the ends like you would to strip off plastic insulation.
 

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