Ideas for getting cut motor brush cap off

[Dale]

I'll check tomorrow and let you know.

[fwharris]

Unfortunately it is more than just the cap that melted, the whole channel that holds the brush is melted and deformed. The brushes actually only have 92 hours on them, not sure what happened.

Yes, very unfortunate! What condition was the brush in the melted side? It would be good to know what internal part failed?

[boilermaker]

I had the very same problem after changing brushes. The brush channel melted and the cap was stuck. I had only about 60 hours on the new brushes. There was not an obvious short that I could see. Also the new brushes with 60 hours were wore almost as much as the ones I removed that had over 300 hours. I am not sure what caused this but wondered if maybe the black cap was not tight enough and caused a short.

[Mike58]

is it possible the armature is worn and putting new brushes in is creating heat from the new brushes only partially contacting the worn area on the armature. Seems this has happened to more than just you based on comments. If there is only a small contact area on the new brushes they could possibly be getting hot due to the current draw being in a small area. The armature may need turning to provide a flat contact for the brush to sit on.

[Digitalwoodshop]

My thoughts are dust getting sucked into the cooling slots near the brushes then throught the motor and out the muffler.... Excess dust getting between the brush and the spinning copper and causing a arc and the resulting heat that melts the brush holder.... The "ARC"...

So my questions are? Do you have dust collection? How much dust did you find inside the case?

AL

[Mike58]

the armature in the picture needs to be machined. It is worn down where the brushes contact it. New brushes on that armature will only have contact with the brushes at each end where the armature is worn until the brushes wear down to contact their full face contact area. That's what I was talking about exactly there. In automotive rebuilding that is a standard practice to machine starter and alternator armatures so they are flat across the width of the brushes. There's plenty of dust inside as you mentioned as well that isn't helping probably. I ran my machine yesterday 7-1/4 hours and the bag was clean when I removed it running a DC system.

[Dale]

I have a RingNeckBlues with a dust collector not a shop vac. My motor had about the same amount of saw dust in it as Al's picture. The 1st picture is of the good brush, seems like it is worn down alot for 92 hours. I have not taken the bad one out yet, guess I'll have to break the plastic to get it out. I apologize for the last picture the camera batteries were going dead.

[Mike58]

armature looks very rough where the brushes ride to me. It doesn't have a sunk in worn place from the brushes though. You should sand the armature down before putting that back together. Strips of emery cloth wrapped around where the brushes ride and smooth the rough places down. You don't want to sand flat spots into it which will create problems too. Think of the rough area as a file eating the brushes as it spins.

[Hasher]

I have had the same problem, where the brush cap melted. Destroyed the cap getting it out, managed to save the motor housing. Does anyone know where I can get a new brush cap?

[Digitalwoodshop]

Here are pictures of the motors over the years, you can see the dates. So far I have retired one motor with over 1000 hours and 4 brush changes.... Went for a 5th and it looked too bad... Just swapped the Armature from a parts motor and was back up. I have 4 machines but only use one now and that one not since November...

Do you cut plastic? Lithos?

AL