coffeetime

The other morning I was making some drawers. I set up the miter saw for some cuts. The first cut went fine except I herd a pop in the switch when I let it go. I have been hearing this and know I need to check it out. On the next cut...nothing! I found the breaker poped. I rest the breaker and the saw comes on by itself and running BACKWARDS! I turn breaker off and go check saw out. Everything looks good, switch not stuck or nothing amiss. I turn breaker back on and all is okay. So I make my next cut just fine. But after releasing the switch the saw stops then starts on its own running backwards again! I pulled the plug and went to the house for a cup of coffee.
Later I take the handle apart to check the switch , lots of saw dust in there so I clean it out real good. The switch even feels better now, snapping on and off. I then pull a brush to check them for wear, they look good except for the arcing from running backwards. After putting it all back together the machine runs great without any pops in the switch. So go figure?

Mike

Corndog

Ah yes...the psycho kinetic powers of sawdust. Just make sure you ain't got a fire hazard there Jack....

Tweegs

Interesting.

The fact that you mention brushes strongly suggests that the motor is DC. Swapping the polarity on the motor will cause it to run backwards.

There is a whole host of potential causes for this.
What I'm struggling with though, is I didn't know there was a miter saw out there that ran on DC.

What is the brand of the saw and how old is it?
Is it battery powered?

skymaster

Corndog; Ahhhhhhhhhhhh can ya FEEL that energy just surging? Ya did overlook the other part of that Physic energy field. Da Sawdust Gremlin!!!!!!!! Betcha he fed it after midnight! Might a even spilled a bit of coffee on him and ya know ya cant ever ever get him wet!