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Old Dec 20, 2012, 10:11 AM
Not dumb, just un-enlightened.
United States, FL, Auburndale
Joined Jan 2010
77 Posts
Aileron Bounce

Has anyone seen / experienced this? When I move the ailerons the left one "waves" or bounces. The right one is OK.

It happened when I first put the plane together, but stopped after I cycled the aileron hinges a bunch of times. Now it is back.

Please advise
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Old Dec 20, 2012, 11:18 AM
Visitor from Reality
United States, VA, Arlington
Joined Dec 1996
12,788 Posts
Most likely the feedback potentiometer in the servo on that side. The pot is a circular resistor, part of the control circuitry that sends the servo to wherever you, via the transmitter and receiver, want it to go. It could also be the associated electronics.

What's happening is that the servo reaches your desired input position and overshoots it - this happens normally, but to such a tiny amount, you effectively don't notice. In this case, it overshoots a lot, then overcorrects back in the opposite direction, taking several overswings before the overshoot dampens to zero.

It going away and returning as you describe could be down to some dirt around the potentiometer's internal resistance track being wiped out of the way, then returning, or just a bad unit from the off being prematurely 'worn out' or unserviceable. As there's little point in 'servicing' electronics at this level, the only practical solution is a replacement servo and hoping it's not also connected to the receiver.

A quick check would be to swap the servos - no need to physically move them, just plug the 'bad' left servo into the receiver output for a 'good' one. If the servo is the issue, it will behave the same regardless of what's feeding it.

Have you contacted whoever you bought the model from? This is where you find out about customer service - it could be anywhere from a new part hitting the mail to you being ignored completely these days.

Good luck

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Old Dec 20, 2012, 12:27 PM
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Melbourne, Australia
Joined Oct 2005
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I totally support DERECK, I had a similar problem with my TopFlite C182, one aileron would constantly "twitch" after any input was put in. I swapped channels on the receiver and the problem persisted with the same aileron. I was initially suspecting the aileron extension leads and considered swapping them for twisted extension leads, but for troubleshooting ease I first tried swapping the "problem" servo. This fixed it, problem solved!
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Old Dec 20, 2012, 01:21 PM
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Joined Jun 2010
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Some old guy at my local field told me that some servos do that when they are about to fail so I would also agree with the others. Looks like your going to need a new one.
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Old Dec 20, 2012, 02:23 PM
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USA, KY, Edgewood
Joined Dec 2007
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Time to replace......
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Old Dec 20, 2012, 04:29 PM
Not dumb, just un-enlightened.
United States, FL, Auburndale
Joined Jan 2010
77 Posts
Thanks everyone! I have a personal rule that says "If one person tells me something, it could be an opinion. If two people tell me the same thing, it could be a coincidence. If three or more people tell me the same thing, I better listen." That rule has served me well and surely applies now. Thanks again.
Now, time for this NewB to figure out what is needed and how to change it.
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Old Dec 21, 2012, 09:08 PM
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Winchester VA
Joined Nov 2006
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If there is a Y connector that is probably the culprit
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Old Dec 22, 2012, 08:20 AM
Not dumb, just un-enlightened.
United States, FL, Auburndale
Joined Jan 2010
77 Posts
News from Hirizon Hobby

I sent Horizon Hobby an email in which I posted the link to the video I posted here, on RCGroups. They sent back a reply. They believe the problem is the servo and rather than have me send in the wing for repair, they are going to send me two (2) replacement servos and I can replace it myself. I hope that is the solution, but, if not, I will move on to the Y-connector. Thanks all of you for your guidance. I am really a NooB to a lot of this stuff.

I'll try to keep everyone posted. They will not ship from the California store until Dec 26, so it will be a while before I get them here in Polk City, Fl.

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Old Dec 25, 2012, 07:08 AM
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United States, MA, Mendon
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I would also suggest investing in a servo tester. They can be purchased online for $5 and up. Very useful tool to have in your shop.

BTW, does the servo do the same thing with the linkages disconnected?

In the past few months, I have had 3 brand new servos (2 Futaba, S3114 and S3157 and 1 Hitec HS 81) fail...one of them caused the loss of a brand new Corsair on its maiden. So, defective servos do happen, even straight out of the box.
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Old Dec 25, 2012, 04:03 PM
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walterboro s.c.u.s.a
Joined Jun 2004
817 Posts
It's funny, I just had the same exact thing happen to me.Turns out it was the Y-harness.But it is prolly a bad servo in his situation.
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Old Dec 28, 2012, 02:54 PM
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United States, CA, Calabasas
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Glad you're replacing the servos. Otherwise, this would probably be your result... http://www.rcgroups.com/forums/showthread.php?t=1792870
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Old Dec 28, 2012, 06:15 PM
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Nashville TN
Joined Jan 2007
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Bad pot in the servo...
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