Thread: Discussion Marutaka Pitts Special S-2
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Old Jan 28, 2007, 05:03 PM
BEA flyer is offline
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I did try 5s lipo and the 780Kv with an 11" diameter X 5" pitch two blade prop in the aforewmentioned PCALC and got numbers which should work:46.8 amps 724 watts output@ 91% efficiency (this was a neumotor spec)static thrust 99.4 oz. pitch speed 56.5 mph. I would reitterate my experience I had with 12 c lipos, and that your 22 amps on a 4400 Mah battery is 5C. If you have two, run them in parallel. At 44 amps you would get 5C again from 8800 2P 5S, and should again give you 12 to 15 minute flights. I remember with 1200 SCR nicads we used to be thrilled with 4 to 5 minutes.

Brushless motors do get hot too, I think from induction or resistance.

I have an Hyperion 2213 and I love it. Pulls a 2 lb plane almost straight up with an 11-6 on 3 lipo cells. They are really well made. The 6 pole zero loss inrunner stylee may be a little bit more efficient. They claim 90%. I would think a can motror may be easier to mount in a glow model than the outrunner. I have an AXi 2820-10 and love it too. Also a Jeti Phasor 30-3 which I think is 6 pole, around 1000Kv. It gets hot after 5 minutes at 400 watts on 12 volts. Actually it threw a magnet off the rotor one time and now has a kevlar wrapped rotor, running it in a belt drive with 15 nicads. You can run these motors hard but make some provision for cooling them or stop and let them chill onc and a while.
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