Universal motor released its magic smoke!

mypcbis$crewed

Nov 29, 2009
58
Joined
Nov 29, 2009
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58
How do I put it back in so I can get back to work :p

Seriously, I have a universal motor for a miter saw that smoked today. I took it apart and found the coil field windings cooked. I unwound it and counted 60 turns of 24g and 46 turns of 18g per side of the field (2 sides). The only reasoning I have for its failure, aside from it being 6 years old and used heavily for a time is most recently I used it continuously on for a good 5 minutes with a 2-3 minute break and on again two or three more times. I am wondering if the duty cycle was too long for this product. Mostly they are designed to do a quick cut.

Are there any tips for rewinding and are there any other items I might want to test before putting the rebilt field back in and testing the saw?

Thanks in advance :)
 

Resqueline

Jul 31, 2009
2,848
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Jul 31, 2009
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2,848
Duty cycle may def. be an issue, as is a hard life.
The armature (rotor) may of course have short. That's more common than field failure but you may be lucky. Checking for that requires a "growler".
Feeding the wire through a small plastic tube while rewinding will prevent it from being scratched by the edges of the pole pieces. Painful work..
 
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