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Old Sep 25, 2012, 04:11 PM
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Originally Posted by DuPageJoe View Post

You're probably sending that motor to an early grave and shortening your flight times running that motor at 17A. The HK 5X3 data looks consistent with that for a high price motor in the same class, the AXI 2208/20. That motor has KV of 1830 and a 16 A limit. According to the Adam_One calculator, it's turning near 18600 RPM with a 5X3 and 3S, while drawing about 6 A. The Watts to heat curve goes up to 40 at 17A in.

Using a 6X3 or 6X4 might get the current down to 10-13A and spare the motor.

Thanks for the concern Joe and the heads up. Up until yesterday I have not had a watt meter to check current flow. That said my only indication that I was pushing a motor to hard was heat. Higher amps produce more heat. Heat kills motors. So my understanding is as long as the heat is reasonable anything goes.

The motor in question has well over 100 flights on it. 60 plus of those on my original DSE ( Its still flying ). So far I have not had heat issues with those props. so I have to assume I am not causing damage by using them. That led me to believe the HK data was incorrect. The motor also comes with a Heat Sink. I think this is also a factor.

I fly in a windy area so I burst my speed a lot as I am flying. I don't fly full throttle for extended periods of time though. So far this has been working for me and the motors are holding up fine. Can you imagine flying that plane I just made in 10 plus mile per hour winds with 1/3 of the wattage? At 200w it flies great.

Btw... I also use a 7x6 prop on that motor though that does seem to warm the motor up a bit so I stopped using it.

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