Burned motor in chop saw?

[krzemienr]

I acquired a Milwaukee heavy duty 14" chop saw from work today. I was told the chop was was broken, so I wanted to see if this was going to be a fixable tool. I took it apart, noticed that one of wires for the brushes from the switch was rubbed through, so I cut out the damaged part, soldered and heat shrunk the wire. I noticed the brushes were worn out, so I replaced those with a set of brand new ones I had purchased for my sawzall, as they were the same ones. I noticed that one of the tabs on the motor was a little damaged (see picture below). I put everything back together, and it will run for about 5 seconds and then pop my breaker in the garage. I tried different outlets, adding an extension cord, and nothing helps. The saw turns on with no delay, runs for about 5 seconds, then pops my breaker. Nothing else is turned on in the garage other than my lights. The tag on the saw states 15 amps needed, I have a 20 amp breaker. Could the damage to the tab on the motor be causing this? Thanks for the replies.

Here is the picture:

 

[brownfoot]

you need a new armature, that "tab" is lifting when it rotates/heats up and shorting to the next tab
you may be able to clean under it and epoxy it back in place, but doubtful it will last very long

 

[krzemienr]

Thanks for the quick answer, I figured it was something like that. Will place an order for one, as it's really not that expensive. Thanks

Rafal