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Old 01-28-2007, 02:14 PM   #1
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Default How small is too small...commutators?

How small is too small when cutting your comms? Is .270 the limit for regular comms? What about large comms like on a Reedy?
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Old 01-28-2007, 02:32 PM   #2
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Word up Dave.. I've heard .260/.265. I have one at .268 and seems to run pretty decent still. I'm not a motor-head, but it runs pretty good. Trust the seat of your pants. Ask big Phil on Tuesday. He's an old wiley veteran at motor tuning.
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Old 01-28-2007, 02:34 PM   #3
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Quote:
Originally Posted by sportpak
Word up Dave.. I've heard .260/.265. I have one at .268 and seems to run pretty decent still. I'm not a motor-head, but it runs pretty good. Trust the seat of your pants. Ask big Phil on Tuesday. He's an old wiley veteran at motor tuning.
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Old 01-28-2007, 02:36 PM   #4
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I've noticed many stock motors can start to suck past .270, losing lots of torque and efficiency.
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Old 01-28-2007, 02:44 PM   #5
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Whats wrong with you guys. True that baby til it peels off.
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Old 01-28-2007, 02:53 PM   #6
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When you go much past .270, you risk peeling the comm off. No big deal if you don't mind blowing up your diamond bit and getting hit in the face with an armature.

Also, when you are down that small try narrowing your brushes a bit. The increased surface area of the brush wrap increases the dead area that is shorted.

Try this. Comm diameter divided by 2. So, a .270 comm you should narrow your brushes to .135. Then you will have perfect wrap with no shorting.
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Old 01-28-2007, 03:10 PM   #7
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Can someone tell me what it is in mm?

Thanks.
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Old 01-28-2007, 03:20 PM   #8
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.270 / .03937

6.86
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Old 01-28-2007, 04:16 PM   #9
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What about big comms?
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