# rotor sizing



## r.wesson (Jan 21, 2008)

I am hearing alot about the numbers of a rotor so what does a rotor with bigger numbers do versus one with smaller numbers torque, speed,etc. Thanks.


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## KOZ (Mar 8, 2002)

r.wesson said:


> I am hearing alot about the numbers of a rotor so what does a rotor with bigger numbers do versus one with smaller numbers torque, speed,etc. Thanks.


typically the larger dia rotor has more torque,smaller diameter generally has more rpm.

Stronger gauss {magnetic strength} usually makes more torque and can run cooler,and pull more gear,versus a lower gauss strength rotor usually makes more rpm,and would need to be geared lower.


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## TeamGoodwrench (Oct 14, 2002)

OK -- so for oval racing with a Epic D3 -- they have 12.3 and 12.5 mm rotors that are both marked "high rpm". Which should you use ??


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## RPM (Dec 20, 2004)

TeamGoodwrench said:


> OK -- so for oval racing with a Epic D3 -- they have 12.3 and 12.5 mm rotors that are both marked "high rpm". Which should you use ??


If the track rules allow this I would run a 12.5 rotor:thumbsup:


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## RPM (Dec 20, 2004)

KOZ said:


> typically the larger dia rotor has more torque,smaller diameter generally has more rpm.
> 
> Stronger gauss {magnetic strength} usually makes more torque and can run cooler,and pull more gear,versus a lower gauss strength rotor usually makes more rpm,and would need to be geared lower.


So true!
I'm finding higher KV motors like the bigger rotors.
Gear to the moon! LOL!


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## caalvord (Mar 12, 2010)

who sells the most affordable tool for checking motors?


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## Hastings (Aug 9, 2002)

Depends on what your checking. If your looking at Induction numbers, theres the BK meter not sure off top my head what model number is, around 100 bucks or so I believe.

If your looking at resistance numbers theres the MMS meter. I believe the new one does everything.....don't quote me on that though!!!!!


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