Sparking angle grinder


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Old 08-31-16, 04:22 AM
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Sparking angle grinder

Hello everyone,

My grinder (which is a few month old. no warranty) started sparking more than usual so I replaced the carbon brushes and they were almost totally gone, one of them actually flipped on its side. But even with the new brushes, the grinder still sparks a LOT more than normal. I disassembled it and cleaned the body thoroughly with the air blower, and cleaned the commutator with a toothbrush along with the blower, but that didn't do much help and I'm running out of ideas. Could this be caused by lack of lubricant? Is there a better cleaning technique in this case?
Any idea guys?

Thanks in advance.

ps/ there are no problems with the wires like exposed one or anything
 
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Old 08-31-16, 04:47 AM
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What brand is the grinder? Where did you buy it?
 
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Old 08-31-16, 04:49 AM
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There can be multiple reasons for excessive sparking. This page details some reasons.

I know my grandpa used to clean out the commutator with a hacksaw blade and lightly go over the grooves with a triangle file.

If you replaced the brushes but not the holders, I would say that the holders are damaged, at least on one side, allowing the brush to chatter and vibrate.
 
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Old 08-31-16, 09:42 AM
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I'm not sure how you were able to use up the brushes in a couple months. My Metabo has seen 10+ years of commercial use and it's still going on it's original brushes. I would look closely as XSleeper mentioned. There may be some other problem causing the brushes to wear so quickly.
 
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Old 09-01-16, 01:27 AM
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Thanks guys for your input, and thanks for the helpful link XSleeper.
This grinder actually I got for only $30. I got it cause I needed a variable speed grinder and it was the only one nearby.
The brushed did ware off fast, but this is actually my firs time dealing with cheaper power tool and a variable speed grinder so I didn't know what to expect. I also did use it quite a lot in the short time I had it.
 
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Old 09-01-16, 05:57 AM
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I once bought a cheap grinder ($10 Chicago Electric) in a pinch when I needed one to grind some concrete on a job... it literally lasted 10 seconds once I plugged it in and put it on the concrete. When it comes to tools, cheap no-name tools are usually just that. Some work good, but it seems a high percentage are lemons that need to be returned or exchanged for a refund.

I have 2 Bosch grinders I have used and abused... no complaints.
 
 

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