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Old Dec 18, 2011, 06:01 PM
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Joined Dec 2011
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Low kv on brushless motors on Quads?

what effect does the KV value on the brushless motors has in use on quads?
For what i know the quad is going to be more stable with lower KV value..
Why is it so? ist there a limit for how low it can be and for how hight it can be?

I have seen this great mk clone quad with 1300KV value motors and it was totaly stable. maybe it depends also on what controlboard it uses?

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Old Dec 18, 2011, 06:05 PM
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United States, CA, Fresno
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lower KV needs either larger props or higher voltage batteries...

750kv is usually 4s, 1000kv is 3s and over 1500 you getting into the 2s range
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Old Dec 18, 2011, 09:07 PM
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Martin the lower kv motors with larger prop are a little more power efficient than a high kv motor with smaller prop. If slow flying with max flight time is your goal go for the former but if fast response and acrobatics are your goal then go with the latter.
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Old Dec 18, 2011, 09:25 PM
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Joined Feb 2007
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General multicopter direct drive brushless motor Kv range rules: Larger than ~70-30cm diameter, ~>1kg AUW, ~700-900Kv, 10-14in props. Smaller 30-20cm diameter, ~500g-1kg ~900-1300Kv, 10-7in props. Even smaller 20-xxcm diameter, <500g, ~1300-2200Kv, 7-3in props...etc. *Note: Motors must be properly chosen/sized to push the size props chosen for total flying wieght(AUW). Approximate motors sizes are: ~28 or> for AUW >1kg, ~20 or> for AUW ~500g-1kg, <500g, ~10-20 for AUW <500g
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Old Dec 18, 2011, 09:45 PM
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I know there has been lots of studying done on what KV motors works best on these Multi-rotor copters however, I am personally learning there are many factors that goes into what is best for each application. The lower the KV in connection with motor size, means a larger prop may be used. A large slow spinning prop is much more efficient then a small prop at high revolution. I am personally using 900KV motors and Love them, would like to experiment with some 1100 and 1400 KV with some APC Electric Thin props. If one has the money to burn (I know this is a understatement) Experiment and find out what works best for the given project.
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Old Dec 20, 2011, 04:52 AM
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Thanks, i Will go with Low kv on my camera-quad and build a smaller one with my hextronic
1300kv motors
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