Bosch motor blue sparking

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FatmanG

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19 Nov 2019
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Leeds
I have taken delivery of a circular saw today and when I tried it immediately blue sparks (they looked blue) were seen through the case to the motor. I checked the brushes which you could see were brand new. That's me all out of ideas. Id rather not speak about sending it back etc my head is literally spinning because of that place, I'd like to know if it can be fixed or worth getting fixed?
Thanks
FG
 
No problem, I've got an old Wolf Sapphire Drill somewhere that when you fire it up it looks like a techno rave is going on inside the drill :lol:

You could probably improve it if the commutator looks a little dirty by sticking a cotton bud in the brush hole and wiping any carbon off the commutator bars.
 
As long as the sparks are fairly small and are all well contained inside the motor housing, no problems. If they are fat enough to be jumping out of the case, then its a fire risk and needs to go back.
 
Thanks Bob, they are definitely contained just very loud and for a novice like myself the first time I tried it I literally s### myself. I'm going to clean the commutator like Trev says and see how it goes. I'm trying to take positives from it like finding out what a commutator is. Its good learning new stuff and will help me potentially in the future.
FG
 
I would not do anything.
If it is brand new, then the brushes should bed in and the sparking will subside.
 
The brushes are brand new lurker the saw isn't its a 110v Bosch pro.
FG
 
The "brushes" are actually rectangular blocks of carbon, pressed by a spring against the rotating "commutator".
think about that, a flat square end pushed into a round piece of metal.
The brushes wear at that tiny point of contact quite quickly. Very soon the square ends become concave and fit the ring quite nicely. As that happens you will get less and less sparks. Untill they wear out and then start making grinding noises as well as sparking.

From what you describe there is no need to do anything but learn how to use the machine.
Just the really obvious stupid question that has to be asked; youre not trying to run that 110 volt from a 220 volt supply? No, didnt think so but it has to be mentioned. 8) 8)
 

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