# diagnosis/repair of brushed motor overheating/stopping



## major (Apr 4, 2008)

dtbaker said:


> ...not quite an EV issue, but I've come to know and respect the 'cloud knowledge' of the group regrding all things electric, and motors in particular.
> 
> I have a vacuum, with a nice little 1500 watt brushed motor. Only 6 months old, stopped working today amid hot smelling electrics from motor area. I let it cool down, and it would run for a few seconds and quit. So I pulled it apart.
> 
> ...


Sounds like a stuck brush or maybe an annealed spring. Got photos?

Brush has to be able to cleanly contact the comm surface with appropriate spring pressure and slide freely up and down the holder. It has to be of sufficient length and not worn down too short. If you can clean it and get it properly fit to the comm, just use it. If not, see a service center for new parts.


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## dtbaker (Jan 5, 2008)

major said:


> Sounds like a stuck brush or maybe an annealed spring. Got photos?
> 
> Brush has to be able to cleanly contact the comm surface with appropriate spring pressure and slide freely up and down the holder. It has to be of sufficient length and not worn down too short. If you can clean it and get it properly fit to the comm, just use it. If not, see a service center for new parts.


seems to go back in fine and slide up and down w/o binding. lots of length left. just wondering if other brush has more surface area, this one starts toasting with high amps in limited contact area?


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## major (Apr 4, 2008)

dtbaker said:


> seems to go back in fine and slide up and down w/o binding. lots of length left. just wondering if other brush has more surface area, this one starts toasting with high amps in limited contact area?


It doesn't look real bad. Has some threading on the face. If it was an EV motor I'd suggest turning the comm and reseating. But in your case, I'd try switching the 2 brushes and see if the problem stays with the brush or with the location. And those types of springs can get squirrely. First thing which comes to mind is too low spring force.


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## dtbaker (Jan 5, 2008)

major said:


> It doesn't look real bad. Has some threading on the face. If it was an EV motor I'd suggest turning the comm and reseating. But in your case, I'd try switching the 2 brushes and see if the problem stays with the brush or with the location. And those types of springs can get squirrely. First thing which comes to mind is too low spring force.


probably easiest to jut replace brushes and see if that works. gonna be an adventure to see if I can get parts.


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