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Old Jul 10, 2012, 10:17 PM
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where is my power going

Hi, all. just been flying for a short time and i haveproblem.. my plane is a techone spirit epp foam, my radio is a dx6i, motor isa 1900kv, and a 10amp esc. prop 8x4. batt 2s 800mah turnigy 20c.(new). after being in the air for only 30sec i must go to full power to keep the plane moving . power really drops off.no loops no rolls just plane flying. where is my power going? please help have not been flying for two days. your friend groundman.
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Old Jul 10, 2012, 10:42 PM
Wake up, feel pulse, be happy!
C₄H₁₀'s Avatar
United States, AK, Fairbanks
Joined Aug 2009
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Do you have a wattmeter to check system performance? It sounds like the battery is too weak (could be even if it's new) and the voltage is sagging quickly after takeoff, but it's difficult to know much without having an idea of what the system is doing.

Another possibility could be something to do with the ESC. It might be some type of soft cutoff or slow-down feature that's being triggered prematurely, but then the question is what that cutoff is and why it's being triggered.
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Old Jul 10, 2012, 10:56 PM
I think I'm inverted. Maybe.
acetech09's Avatar
United States, CA, Pacifica
Joined Apr 2012
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I'd check the pack voltage on your nano-tech, and make sure it isn't defective.
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Old Jul 10, 2012, 11:03 PM
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And what are you using to charge your battery?
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Old Jul 10, 2012, 11:11 PM
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so i assume i,m useing the correct prop? i was told to go to a 9x4 prop, i.m confuse bigger prop more power,smaller prop more power.
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Old Jul 10, 2012, 11:20 PM
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i.m useing a thunder power charger, 8,40v when fully charged,2s i charge at 0.75 volts.
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Old Jul 10, 2012, 11:22 PM
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sorry i mean 0.75 amps
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Old Jul 10, 2012, 11:34 PM
I think I'm inverted. Maybe.
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Can you link the motor you're using?
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Old Jul 11, 2012, 12:00 AM
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United States, AZ, Mesa
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I think you need a better ESC, maybe you're hitting some kind of safety limit. Does it get hot?
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Old Jul 11, 2012, 12:02 AM
I think I'm inverted. Maybe.
acetech09's Avatar
United States, CA, Pacifica
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I think I know the motor he's using. Only 1900kv motor on the HK that recommends a 8x4. It draws just under 10A at that size. Good idea to check anyway.
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Old Jul 11, 2012, 08:36 AM
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I have no meters to check esc, but i do have the money to buy another esc. so what esc would you buy to make things right? motor is a t-2006 1900 kv. and yes the esc and motor gets a little warm.
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Old Jul 11, 2012, 09:46 AM
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dedStik's Avatar
United States, VA, Virginia Beach
Joined Feb 2012
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Quote:
Originally Posted by groundman View Post
so i assume i,m useing the correct prop? i was told to go to a 9x4 prop, i.m confuse bigger prop more power,smaller prop more power.
I think 1900kv using a 9 would be over prop. I've a 1700kv and it's maxed as far as prop at an 8x4.8 anything larger I'll burn up the motor. You mention in another post in this thread it's a 10 amp, I'm assuming this is one of the Blue Wonder style 24gram motors.

Higher kv is generally less torque more speed ie smaller prop. Lower kv larger prop slower rpm more torque. If I'm wrong please correct me. I don't want to give someone bad information.
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Old Jul 11, 2012, 09:47 AM
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I would go up to at least a 15-amp ESC on that setup. You NEED to check the power output on these things. Sometimes you can get a recommendation but due to differences in batteries, air pressure, and motor construction, your setup could be vastly different than someone else running the exact same stuff. So, you can either measure carefully, or give yourself a wide safety margin, preferably both.
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Old Jul 11, 2012, 11:11 AM
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LaGrange, GA
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Do you have a flying buddy that could help you? Have you tried more than one battery and does it do the same thing with both batteries? I'd try a different battery first just for kicks because that's obviously the easiest thing to swap out. If you don't have a flying buddy you could borrow a battery from, I'd order a 2nd battery, a 15 amp ESC like Jasmine recommends and some type of wattmeter if you can spring for one of those. You've GOT to be close to overloading that 10 amp ESC with that setup. Hang in there. My first electric I build, I got an incompatible motor and ESC. I had a very similar problem. What *I* had to do in *my* situation (but I'm not recommending this) was set my ESC to think my Lipo was a Nimh pack. After that, my problems went away. I flew and flew that plane until I let my son fly it, he got downwind over some trees, couldn't get back and flew right into the top of a tree. Don't give up!
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Old Jul 11, 2012, 11:14 AM
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I had the same problem with my first plane too. I wad using the recommended setup, but it melted the motor. Two warranty replacements later and I bought a watt meter and figured out what the problem was.
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