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Old 02-26-2007, 07:09 PM
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salnsp
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Default RE: Will brushless reduce Current?

Sorry! I don't agree with Dan on this one. First of all compared to a brushed motor the brushless will be more efficient than the brushed setup. The AP-29L will not be able to take 50 amps amps for reliable sustained flight. The motor will not be able to take over 3 cells without burning out so the best solution is a brushless motor.

Before we get into that. I would also look at the battery. The max that any 2100 cells can output is 15 C (this is assuming a battery from one of the major manufacturers). This means that you can only count on a max of 30 amps for sustained flight. This is probably not enough for a good hi power setup. I would consider switching to one of the 25C 2070 batteries from ThunderPower (or an equivalent Duralite, Hyperion, PolyRC, Polyquest, etc). This will give you a max of 50 amps for sustain flight and a high RPM because the voltage will stay higher under load.

For the motor I would find look at the Kv of the brushless motor that you are using now. I would then look for a motor of the same size in a brushless. Since you amp draw is now 30 amps. I would look for a motor with a kv of approx. 25% motre. This should get you up around 45 amps or so and with a resultant increase in power of close 50%.

Please keep in mind this is a calculated best guess.