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Looking for a prop to test

Posted: Fri May 11, 2018 8:40 am
by the-mailman
Does anyone have a 12X7 prop I could borrow? I'm setting up a new plane and want to maximize the available motor power. The 12X8 I have over amps the motor rating and a 12X6 is way under so I'm hoping a 12X7 will do the trick, but I don't want to buy one I might never use if it's still too much for the motor.

Thanks,
Bruce

Re: Looking for a prop to test

Posted: Fri May 11, 2018 11:57 am
by retiredVTT
I'll have a look Bruce, and bring what I have on Saturday.

Re: Looking for a prop to test

Posted: Fri May 11, 2018 2:16 pm
by steve
What motor and Plane Bruce ?


You can try one of the various prop calculators from the web but it would be interesting to see the amp draw on a 12x8 GWS HD prop. My sense is that it would pull less amps than both an APC 12 X 8 and 12 x 6 SF or E props yet provide the same or more thrust. I am always amazed at the GWS props for sport or 3D flying.

On a side note, I didn't think I would ever use a 12" prop for any of my electrics at Shannon (that's crazy!!) but I had been flying a foamy that used a 14 x7 APC for a few years until the motor bearing went . Point being that it was nice to have the propeller selection on hand way back when even though I never intended to use it. I now have 2 - 14 x 7 APC e props, one new and one used in my tickle trunk. :)

Steve

Re: Looking for a prop to test

Posted: Fri May 11, 2018 8:53 pm
by the-mailman
Hi Steve, it's a scratch built plane that was designed for a .35 - .40 nitro. Weighs close to 2 kg. I put a Turnigy air 3730 580w motor on it. The motor is rated for max 42 amps.

I'm trying to get close to the max on 3s as that's all I have for batteries and I want to make sure I get all the power I can. With the 12x6 I get 440w at 38 amps. If I can get closer to the 42 amp limit I should be able to get another 80w of power. Maybe it's not worth trying to squeeze out the extra power, but I like to experiment.