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General control line discussion => Open Forum => Topic started by: Paul Taylor on October 29, 2013, 04:05:27 PM
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Well I had a little time to kill this afternoon and stopped by the local soccer field before the soccer moms showed up. I had my one battery charged.
It was not the best pattern I ever flew because this was a new plane or at least new to me.
I flew my very first full pattern on a electric plane!!! #^
It was a little windy and I might have been a little fast (9400+-) but this thing pulled like a Hoss!
Prop made a funny sound when i turn a corner. Like maybe flexing? Is that normal? APC electric prop.
Did 12 laps when done with clover and a very nice landing. Plane is balanced spot on.
Cant wait for my other batteries to come in and my next flying session. H^^
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Prop made a funny sound when i turn a corner. Like maybe flexing? Is that normal? APC electric prop.
That's normal. Mine did it more on outsides than insides.
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Congrats Paul. Now you should come to El Dorado this weekend and join in the fun!
Jason
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One thing I have noticed watching some of the newer and better electrics fly, is the difference in prop noise from plane to plane. They don't all sound alike. That makes me wonder, how much of a tuning tool can this be? More noise=more load? And vice versa? Just a curiosity, and it almost makes mechanical sense. Aerodynamics are still in play no matter what is driving the prop.
Type at you later,
Dan McEntee
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Congrats Paul. Now you should come to El Dorado this weekend and join in the fun!
Jason
Hey Jason - wish I could. Going to visit some family this weekend and maybe get some sand between my toes. ;D
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CONGRATS Paul!
I'd be willing to bet that IC props generate similar noises - that get drowned out by motor noises.
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Much of that noise is the props flexing and fluttering, I have watch several very carefully and you can see the prop blades get wider in the corners, you also hear it in hard corners. I have also flown 2 that when the noise happens you can feel the buzzing in the handle, and hear the nise at the exact same time, that happened with the very flexible APC E props that were on the planes.
Randy
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Much of that noise is the props flexing and fluttering, I have watch several very carefully and you can see the prop blades get wider in the corners, you also hear it in hard corners. I have also flown 2 that when the noise happens you can feel the buzzing in the handle, and hear the nise at the exact same time, that happened with the very flexible APC E props that were on the planes.
Randy
That was part of my curiosity as more electric models showed up at contests and such. yeah, they run smoother, bu they still turn pretty high RPM, and on larger models, get loaded a lot due to the torque that the motors make, especially in corners like you say. And yet, most of the props looked like the flexi-flier props that park flyers use, just a bit heavier. I wonder why they need to be a certain style and shape, and why props for internal combustion engines would work just as well on a electric motor as they do on a PA61?
Just curious,
Dan McEntee
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IC props tend to be thicker/heavier. Folks report up to 20% higher power usage for an IC prop versus an electric when both are turned for similar speeds & flight power.
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IC props tend to be thicker/heavier. Folks report up to 20% higher power usage for an IC prop versus an electric when both are turned for similar speeds & flight power.
Can you use a IC prop on a electric?
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Yes you can, and as Dennis said, you will probably loose some efficiency. :)
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One thing I have noticed watching some of the newer and better electrics fly, is the difference in prop noise from plane to plane. They don't all sound alike. That makes me wonder, how much of a tuning tool can this be? More noise=more load? And vice versa? Just a curiosity, and it almost makes mechanical sense. Aerodynamics are still in play no matter what is driving the prop.
Type at you later,
Dan McEntee
Excellent point, Dan. I think you are exactly correct and it would be something I'd investigate were I to go electric. Unfortunately, experimenting with props while holding my nose closed would be difficult.
Ted
Juuuuuuuuuuuuuuuuuuuuuuust kidding. Sheeesh! (added peremptorially in breathless anticipation)
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Nice! I'm going to steal a flight next time I'm home :p
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Nice! I'm going to steal a flight next time I'm home :p
Come and get it buddy!
Anything to get you back on the handle. y1
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Is the noise prop flutter? Slow-fly props are known for this in the RC world. I have also seen other lightweight props flutter in static runs.
I have even had o-rings on a prop-saver come off from the vibrations.
My understanding is that a combination of prop flex and prop stalling is taking place. The sound is awful.
Giving an airplane throttle just to have the prop and plane part company is worse.
Phil
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What plane is your electric set-up on?
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What plane is your electric set-up on?
The plane is a Tutor II profile. All Tom Morris stuff.
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Please Paul
can you tell us your model set up? thanks in advance.
regards
Juan Carlos Pesce
Buenos Aires
Argentina
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Hey Juan
Will try
It's a FM 9 timer and a new castle controller. Battery is a 3300 mha 4s. Not sure on the motor but will check when I get home. It all came from Tom Morris with the exception of the battery.
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Hey Paul,Congrats on that flight!!Was it worth the wait??It only gets better ;D ;D ;D
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Much of that noise is the props flexing and fluttering, I have watch several very carefully and you can see the prop blades get wider in the corners, you also hear it in hard corners. I have also flown 2 that when the noise happens you can feel the buzzing in the handle, and hear the nise at the exact same time, that happened with the very flexible APC E props that were on the planes.
Randy
I agree Randy. I would modify that to say that a flexible prop contributes to that noise. I have had the flexible APC's be very quiet and some very rigid carbon props make terrible noises as well. I have noticed that the slower the prop turns relative to its pitch, the more noise it makes. The 3 blade carbon prop I now use turns about 11k, is 5.5 pitch, flies at 5.4 and is very quiet!
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Much of that noise is the props flexing and fluttering, I have watch several very carefully and you can see the prop blades get wider in the corners, you also hear it in hard corners. I have also flown 2 that when the noise happens you can feel the buzzing in the handle, and hear the nise at the exact same time, that happened with the very flexible APC E props that were on the planes.
Randy
Isn't because the airflow direction through the prop is suddenly changed due to a hard corner (pitch up/down) ?
MASSIVE P-factor going on throughout the radius of the turn ?