# National Carbon T300 brushes from EV-West



## Tesseract (Sep 27, 2008)

brainzel said:


> Perhaps someone could get me some answers.
> 
> Michael


I hadn't heard of "National Carbon" before but a quick search of Google turns up a company in India that does, indeed, make brushes. Not to point out the obvious, but... they have a contact page, so why not send them an email yourself?


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## brainzel (Jun 15, 2009)

Michael Bream from EV-West wrote ma an answer: "_All DC brush manufacturers ship the brushes "broken in". This saves the customer hours of time breaking the brushes in so the curvature matches the commutator._"
That would be great, if you want this, so why don't explain it in the shop?
I remember the discussion at the EVCON about it and the annoying time, customers have to pre run the motors, before putting the pedal to the metal.
So it would be great news for somebody.

But I had some other DIY-guys who had Helwig-Carbon brushes that where flat. So obviously there is a inconsistency.

And it makes no sense, because not all DC-Motors will run only one direction and so the shaping could be counterproductive, or not?

The T300 where recommended to me because of some issues the Helwig brushes had in the Warp9.

Perhaps other T300 customers could illuminate me ;-)
Michael


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## major (Apr 4, 2008)

*National* is or was a trademark of Union Carbide and National Carbon a division. It's been a while since I dealt with them and I wondered if they were still in the motor products business. They made good brushes back in the day.

You can order the brush shaped and cut to your specification. I see no reason not to have the face radius. If flat, you'd spend time and create much dust sanding the shape yourself. Having the radius shape on the new brush is only an approximation of the exact fit required for your particular motor. The break-in procedure is needed to seat and film the brush and commutator surface and cannot be done on the brush alone. Many confuse shape and seat. First shape the brush to the comm. Then seat it. Shaping is independent of rotation direction; seating is, partially.


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## dougingraham (Jul 26, 2011)

You will still need to run those brushes in order to seat them properly. Just because they have the approximate curvature does not make them run in.

I am running the Helwig H60 brushes and they are doing a really good job so far. But then I only have about 2200 miles on them. You cant pull them out of the holders to inspect them without having to re seat them. But my comm has a nice patina.

Best Wishes!


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