Makita belt sander and brushes

[doctor Bob]

In one of my sanders, I put a new set of brushes in and within 10 mins use they are burnt out again, what is wrong?

Regards Bob

 

[Spectric]

You have either got a defective armature or rather than just replacing the brushes I would have accessed the commutator on the armature and given it a clean and especially the gaps between each segment, which should stand proud. How old is the sander?

 

[TheTiddles]

Burned out or worn out? I’ve just kicked my 35 year old lawnmower back to life for the year, which involves sanding back the commutator to take off the soot, sharp edges and burned grass, then it runs like... an old lawnmower. The brushes are right at the end of life but they aren’t the thing that stops it working

Aidan

 

[doctor Bob]

You have either got a defective armature or rather than just replacing the brushes I would have accessed the commutator on the armature and given it a clean and especially the gaps between each segment, which should stand proud. How old is the sander?

Ok i'll give that a go, bought it when I started the business in 2004.

 

[Johnwa]

Sounds like you have a segment lifted on the commutator, ripping the face of the brushes away as it rotates. Unplug the sander and have a look at the com, you'll probably see a segment slightly proud of the rest. If it is I would scrap the armature and fit a new one. I never had much success trying to glue a segment back into place in my working days.

 

[samhay]

Is this a 9401?
If so and you ultimately can't get it working again, please consider offering it up on here for parts. I could do with a replacement drive roller.