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sikeston34m · 12.02.2007, 08:08 PM

One thing that I thought was very interesting is at the bottom of that page. It's how to figure the kv of any motor that's already built.

"Drive your motor with a power drill.
Measure RPM and voltage generated.

Kv = RPM / voltage"

I spun the 4130 at 930rpm with a drill. It was feeding 2.9 volts into a volt meter on the AC scale.

930rpm/2.9volts= 320kv

Pretty close to the factory rating of 305kv! Which maybe with the load of the motor, the drill wasn't quite spinning at 930rpm. I think this is a good quick method though.

	(#216)
sikeston34m RC-Monster Brushless Offline Posts: 2,085 Join Date: Sep 2007	12.02.2007, 08:08 PM One thing that I thought was very interesting is at the bottom of that page. It's how to figure the kv of any motor that's already built. "Drive your motor with a power drill. Measure RPM and voltage generated. Kv = RPM / voltage" I spun the 4130 at 930rpm with a drill. It was feeding 2.9 volts into a volt meter on the AC scale. 930rpm/2.9volts= 320kv Pretty close to the factory rating of 305kv! Which maybe with the load of the motor, the drill wasn't quite spinning at 930rpm. I think this is a good quick method though.