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Re: pic: The Cow that Jumped over the moon!
Quote:
Originally Posted by Jim Wilks
6 CIM's all working near full power? You'd trip the main 120A breaker in a few seconds.
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Bingo.
Quote:
Originally Posted by nighterfighter
Each CIM wouldn't be experiencing very heavy loads though. The stall current is 133 Amps, and the free current is 2.7 Amps.
While they wouldn't be at free current, they wouldn't be drawing massive amounts of current if they are powering a light-weight rotor, would they?
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If the CIM is operating at full power (337W) with, let's assume 0.65 efficiency (max efficiency, anti-conservative, but I'm only making a point) draws about 43A, which can pop each CIM's breaker, and with just 3 (let alone 6) you're running the risk of blowing the main breaker too.
Quote:
Originally Posted by John
Using the method from that website:
Area = #rotors * diameter^2 * pi/4
Area = 4 * 14in^2 * pi/4 = 616 in^2 = 4.28 ft^2
Power will be limited by the battery and main breaker, with a maximum continuous power of:
Power = voltage* current = 12 V * 120 A = 1440 W = 1.93 HP
PL = Power/Area = .452 HP/ft^2
TL = 8.6859 * PL^(-.3107) = 11.12 lb/HP
Thrust = Power * TL = 11.12 lb/HP * 1.93 HP = 21.5 lb
The battery alone is 12 lb. Each CIM is 2.8 lb. If I did the math correctly, I don't think you can fly.
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This too.
__________________
Theory is a nice place, I'd like to go there one day, I hear everything works there.
Maturity is knowing you were an idiot, common sense is trying to not be an idiot, wisdom is knowing that you will still be an idiot.
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