# Silver vs Carbon brushes



## Hornet (Dec 1, 2005)

edit.


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## Hornet (Dec 1, 2005)

edit.


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## Sir Slotsalot (Jan 23, 2010)

Good tips Hornet. Wish all slot motors had silver comm brushes. To me it's worth the extra expense for performance.

Kihm


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## alpink (Aug 22, 2010)

in all applications where I have used silver content brushes, they gave better performance to the motor. the downside is greatly increased wear on the commutator.


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## Hornet (Dec 1, 2005)

edit.


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## slotking (May 27, 2008)

the silver is softer, and will provide more crap on the comm, but copper should wear the comm faster.

on high end arms, the small silver brushes can short out a comm!
you should be ok with the bigfoot silver

just from my humble experience


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## Hornet (Dec 1, 2005)

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## slotking (May 27, 2008)

like i said 
not a problem with bigfoot brushes

just the standard ones


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## Hornet (Dec 1, 2005)

edit.


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## volracer (Feb 12, 2010)

I have had the opposite experience in brushed RC motors. Silver compund brushes are harder, provide less electrical resistance and wear communtators faster than copper compund brushes. Also this seem backwards but, high rpm motors need stiffer brush springs to prevent brush bounce (maintain contact with communtator) than low rpm armatures.


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## slotking (May 27, 2008)

the hotter HO cars used bigger brushes for several reasons
as you say reduce bounce, but if the comm is trued correctly, not much of an issue.
the bigger spring also allows for better current flow
and pressure on the comm for that current flow
and for stability under higher heat, you do not want the spring to collapse

ho silver springs in general are soft and leave more residue

The slottech bigfoot springs are better, they help up the speed of our stock arm cars, but when using a custom arm, just use an arm that give you the speed you want, no need to use silver for more speed


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## volracer (Feb 12, 2010)

Brush bounce is due to trueing the arm, but also balancing the arm. There is no perfect balance. A statically balanaced arm will not be dynamically balanaced. An arm balanced at a low rpm will not be balanced at a high rpm. I have even know people that have bought hand waund arm, stuck them in an oven to "temper" the windings and then send the arm back to be rebalanced without even running the arm.


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## Hornet (Dec 1, 2005)

This is from a few years back,but here's my brush bounce theories

http://ho-tips.net/showthread.php?tid=241


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## 2racer (Jun 15, 2008)

like metals wear at a slower rate so a copper comm and silver brushes the softer metal would wear faster.


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