Overbanking aileron servos
#1

I have a model which has developed a puzzling problem, Using a 2.4 ghz Airtronics/Sanwa transmitter/receiver and digital servos, one on each aileron.
On some flights I have observed turn bank angle increasing after returning the aileron stick to center. This can be corrected with opposite aileron but is disturbing.
I landed to take a look at the aileron movement and notice that usually they seem to be working normally. But then I noticed that sometimes after returning to neutral the ailerons would move off center a small amount with both servos moving in the same banking direction (ie. one up and one down). Since both servos are working the same way I thing they are ok.
So I think this problem must be transmitter or receiver.
If there are any ideas or suggestions from experts here to diagnose the problem, thanks in advance.
On some flights I have observed turn bank angle increasing after returning the aileron stick to center. This can be corrected with opposite aileron but is disturbing.
I landed to take a look at the aileron movement and notice that usually they seem to be working normally. But then I noticed that sometimes after returning to neutral the ailerons would move off center a small amount with both servos moving in the same banking direction (ie. one up and one down). Since both servos are working the same way I thing they are ok.
So I think this problem must be transmitter or receiver.
If there are any ideas or suggestions from experts here to diagnose the problem, thanks in advance.
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init4fun (09-24-2021)
#4

I had a similar issue. Ailerons would 'bounce' once returned to neutral causing an overbank. It turned out that freshly charged 6V receiver battery pack was peaking about 6.7V. Once the voltage flattened out at 6.0 it all was OK again - so the servos on the aileron channel didn't like the higher voltage. If I put a 4.8V pack in, no issues. But with 8 servos, I felt the 6V pack was safer to keep the torque values up over time. A voltage regulator may help.
#5
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For the pots try to work some 3 in 1 oil into them, and your noisy pot problems will be gone, besides that they will operate more smoothly. The oil keeps oxidation off the wipers and keeps the pots nice a quiet,. Worked great for car radio volume controls also, and band switches for that matter.
#6

My Feedback: (19)

Some Airtronics stick assemblies are notorious for breaking wires that connect to the aileron channel pot. I repaired several of these some years back when these radios were popular. I believe this was mostly on the RDS8000 transmitter. The problem was wired that were not flexible enough and would show up as intermittent operation early on before full failure. Good radios otherwise and I still use one to fly a couple of gliders. As others suggested, I would suspect something around the stick pot and this would be one thing to look for.
#7

My Feedback: (19)

Another point after my memory started working. Are you using a “Y” harness on the aileron servos? On numerous occasions I have seen ailerons oscillate or not center well when connected to a “Y”. The problem comes from worn or loose connections and can be cured by unplugging and plugging in all the aileron connections or even replacing the “Y”. Best to use separate channels if you can. One more thing to check.