RC Radios, Transmitters, Receivers, Servos, gyros Discussion all about rc radios, transmitters, receivers, servos, etc.

Need Help, Fast!

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Old 05-28-2003, 05:28 PM
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Richardfast
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Default Need Help, Fast!

After almost 50 flights practicing for a pattern event this coming weekend, the following all of a sudden starts taking place: the plane preflights perfectly, all controls move and neutralize exactly where they are supposed to, nothing is loose, nothing has changed, except ... immediately upon lift off the plane starts rolling right and takes almost 20% (digital) left trim to correct. But the correction is short lived. Put in a little left aileron and the plane starts rolling left on its own, requiring the right trim to come out, etc. There is no roll stability. it is squirrely in either direction. The plane acts like one, or both, of the aileron servos is not centering when the stick is neutralized. But, I can't reproduce this on the ground. Everything is tight and exactly where it is supposed to be. Any ideas would be appreciated.
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Old 05-28-2003, 06:36 PM
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Pugsley-RCU
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Default Wow...

Very strange in deed....

I have to assume you are using 2 aileron servos, so hard to say it is a servo problem. Are they "Y"'ed into a single channel? Sounds like something is going south in the tranny (TX)......

I'd suggest sending it in for a tune up. Have a friend that can loan you one for the contest??????

Pugs
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Old 05-28-2003, 06:38 PM
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MHawker
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Default Need Help, Fast!

I'm just taking a stab at this, but could it be your rudder rather than ailerons? I only mention it because it happened on my Magic after I did some work on it and didn't notice the rudder was off. It was very unstable until I centered the rudder.

Mike
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Old 05-28-2003, 06:43 PM
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Pugsley-RCU
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Default Interesting idea....

meaning the rudder is floating around in the slip stream cause the yaw/roll trim issues????

Good idea to check out...

Pugs
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Old 05-29-2003, 04:53 AM
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Richardfast
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Default Need Help, Fast!

Yes, I use a servo for each aileron, fed by a "Y" connector. The rudder is centered, and the linkage is tight. It is a new transmitter (a Hitec Eclipse w/Spectra module), but I had about a dozen good flights on it before this started happening. Since I started this thread I went back out and tried flying again after another runup at full power, and finding absolutely nothing out of whack. The exact same events are occuring. The plane rolls right on lift off and is extremely unstable in the roll axis. This is so frustrating because I have practiced so hard for my first pattern contest this weekend. Everything on the plane is straight and all controls are tight and where they should be. This morning I am going to go back to my JR transmitter and give it a try. I don't see how this could be a transmitter problem, because I can't reproduce the problem with the plane on the ground. Arrrrgh!
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Old 05-29-2003, 11:58 AM
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Default Need Help, Fast!

It does sound odd... double and triple check everything.
Not sure what plane, or what wing mounting method is in use here,
but make sure that nothing is shifting around, wing dowels not charred/loose, etc...
Then, if you still can't find anything, definitely try the different trans, different
receiver, different servos, etc... don't want to end up losing an airplane over it.
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Old 05-29-2003, 03:22 PM
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Richardfast
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Default Need Help, Fast!

Good news! It is the transmitter. Put my old JR back on the job and problem went away. Bad news is I can't fly the pattern sequence as well without exponential, but at least I have a plane for the contest. I will be sending my new Hitec Eclipse 7 in for repair asap. I still don't understand how the problem is in the transmitter but only shows up in the air. Answer has to have something to do with range, doesn't it? Thanks for your inputs. I will let you know what was found wrong with the xmtr.
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Old 05-29-2003, 04:54 PM
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Default Not sure.....

why a range issue would only show up on a single channel. Very strange.....

Could be vibration......I assume you ran the motor on the gorund while checking?????

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