whats wrong with my motor

[User]

 

[sight-pin]

I take it the brushes are fine and you've cleaned between the commutator, other than that i don't really TBH, But this search brought up some interesting points as to what may cause sparking. https://www.impomag.com/article/2014/11/motors-week-brushes-sparking-and-machine-maintenance

 

[gbb]

The only options you really have, some already covered, remove brushes and thorough inspection, look also for cracking in the carbon itself, had that before although I'm not sure if it's cause sparking. I've dressed off older brushes with a file, perhaps the tips of the carbon get contaminated, again not necessarily would cause sparking, mine have been on the thermocouples on another application...but the contamination can cause problems.
Thorough inspection of the commutator, I've used a hacksaw blade to clean out the undercuts... maybe some electrical cleaner spray to clean off any deposits on the commutator. In the old days i used to use emerytape to clean off commutators on generators. Spin motor by hand as the article states, are the bearings ok ?

 

[Levo-Lon]

Think its as above and a spring pressure fault..
That does spark well .

 

[iateyoubutler]

Short circuit windings. It`s finished, see it all the time at work. New motor time

 

[Globalti]

The commutator is knackered and as posted above, current is shorting between segments. Has it been operating in very dirty or dusty conditions? How old is it?

 

[slowmotion]

The commutator is knackered and as posted above, current is shorting between segments. Has it been operating in very dirty or dusty conditions? How old is it?

I have a very expensive old Numatic industrial vacuum. I "economised" on the vacuum bags. They leaked hopelessly. A few weeks later, the commutator on one motor cracked, and the brushes were only making contact on half of the windings.......turbo speed ensued before a blue flash meltdown. A new pair of motors cost £120.

All for a few pennies saved on the proper bags.