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Old 08-30-2008, 09:42 AM   #1
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Default How to calculate KVs?

Old timer new to brushless, I just bought a EZrun set up (13T?) the sticker reads 3000KV. What is the formula for figuring this out? Thanks for any help.
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Old 08-30-2008, 10:51 AM   #2
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It's actually more of a 'measurement' than a 'calculation'...

Roughly speaking, it is the rating in terms of RPM per volt...

(Example: 3000 KV at 7 volts = 28,000 RPM...) OF course, that does not factor in 'load', or internal resistance of batteries, etc., etc. -- you can't even compare motors from different brands because different manufacturers mesure KV differently...

Correction: 3000 x 7 - 21,000.... Thanks to 'cannon' for the correction. I gotta pay more attention to my own typing....
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Last edited by tfrahm; 08-31-2008 at 12:50 PM.
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Old 08-30-2008, 11:24 AM   #3
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Hey thanks tfrahm, at least I have a ballpark at what I am dealing with. Nice to know that the manufacterers after all these years still cannot standardize(?) a motor measurement/dyno readings. Guess it helps prevent direct comparisons of each others product!?
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Old 08-30-2008, 07:07 PM   #4
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Quote:
Originally Posted by tfrahm View Post
It's actually more of a 'measurement' than a 'calculation'...

Roughly speaking, it is the rating in terms of RPM per volt...

(Example: 3000 KV at 7 volts = 28,000 RPM...) OF course, that does not factor in 'load', or internal resistance of batteries, etc., etc. -- you can't even compare motors from different brands because different manufacturers mesure KV differently...

Last time I looked at mathematics 7 x 3000 equalled 21000
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Old 08-31-2008, 12:46 PM   #5
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Quote:
Originally Posted by cannon View Post
Last time I looked at mathematics 7 x 3000 equalled 21000
DOH!
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