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Old Dec 17, 2010, 11:00 AM
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Originally Posted by rahtware View Post
The data from my kit motor/prop and the replacement motor/prop that HH sent me, as I originally posted on:

Condensed version of data:

Kit motor/kit prop: Average Amps = 11.83; Average Watts = 130.05

kit motor/new prop: Avg Amps = 13.43; Avg Watts = 146.27

new motor/kit prop: Avg Amps = 12.17; Avg Watts = 134.37

new motor/new prop: Avg Amps = 14.29; Avg Watts = 155.26

Seems like the new prop makes up for most of the increase in power... Might just keep the old motor (with the all metal bell), but go with the new prop.

Biggest problem with my data is I don't have a thrust meter. I thought I could feel a difference in "pull", but no way to prove it. And, as Dr Kiwi and others have proved, an increase in power consumed does not always translate to an increase in thrust.
I don't like the idea that we essentially have (2) Radian Pro Threads...but so be it. Here's the percentage deltas I posted in response to rahtware's very helpful work..

Someone please check my numbers on this, but your percentage changes (from stock motor/prop) in both Amps and Watts seem to be:

With just new Motor: Amps= +2.8% Watts= +3.2%
With just new Prop: Amps= +13.5% Watts= +12.4%
With BOTH new Motor and new Prop: Amps= +20.8% Watts= +19.4%

If these numbers are correct...I too am surprised at the relatively small increase in Amp/Watt draw with the new motor.

I would love to see the numbers with the Graupner or EMP 10x8 prop. The EMP has the possibility of yielding even greater thrust.. as per Dr Kiwi's past testing of the EMP line.

Other then actually flying the plane and getting a subjective feel for performance...we might have taken this as far as we can, without testing on a thrust stand.

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