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Old Nov 11, 2007, 09:01 PM
Slowly Approaching 1,000
Detroit (area), MI
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Question
Is there a wattage/pound rule of thumb for helicopters?

Is there a rule of thumb to go by for how much wattage per lb. is needed to fly helos certain ways, i.e. hover, sport, 3d, insanity?

Such as with planes you want 100 watts per lb for "fun" sport flying, 200 watt/lb for exciting white knuckle flying, etc.
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Old Nov 11, 2007, 10:04 PM
Registered User
Toronto Canada
Joined Dec 2002
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It turns out that it requires approximately 50W per pound to hover.

Some helis can go as low as 35W per pound depending on motor efficiency.

The power required to hover is also dependent on rotor RPM.

Slower RPM requires less power, but the stability of the heli suffers.

Most model helis require about 50W per pound to hover.

For the same heli and rotor system, the power required to hover increases as the weight increases to the power 3/2.

That is, Power is proportional to WEIGHT^(3/2)
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Last edited by Martyn McKinney; Nov 11, 2007 at 10:11 PM.
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Old Nov 11, 2007, 10:05 PM
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Joined Aug 2007
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Yep. See section 30.11.2 of the Electric Helicopter Beginner's Guide. Should be linked from a sticky in this forum.

Jeff
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Old Nov 12, 2007, 11:53 AM
Slowly Approaching 1,000
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Thanks guys, I did a brief search and after the first 3 pages of threads and hour+ in front of the PC, I figured I'd ask very specifically. Appreciate it.
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Old Nov 12, 2007, 12:56 PM
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Yeah, it would be great if forum search also covered some sections of the EHBG. Some of the technical explanations in that guide are the best I've seen.

Jeff
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