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Old Mar 13, 2013, 05:46 PM
davidterrell80 is offline
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UM-to-60-inch fixed wing
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United States, VA, Herndon
Joined Apr 2012
4,663 Posts
Thanks for the kind words... I wasn't thinking. When I thought about my Carbon Cub's 90 g, I knew better. I've ordered a Power Up 250 plus from HeadsUp RC that should do nicely. I had larger motors but no one in the 250-300 range.

My spreadsheet tells me that for:
-- 40 mph Vmax
-- 2S system
-- 200 g weight
-- 90 W/lb (so 40 Watt system)
-- 1400 Kv at 75% efficiency
-- 7 A Cmotor
--10 A ESC

That I can swing a 7x4 prop with 6 A on the motor. So I will put an 8040 on it and bench test it in case the efficiency is better. At 80% efficiency the 8040 prop should give 20% more power at 7 A. At lower efficiency the current goes up.
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