All settings still at default. MKS DS95i on 6v with rudder delay at 5 and both tail endpoints around 115. Servo horn length is 13mm, originally tried 10mm but endpoints were up near 170. Linkage is smooth with no binding. 360mm mains, 68mm tails on 6s, 2800rpm, gov turned off. Vibes look fine. Adjusting gain in Tx changes the speed of the oscillation but does not get rid of it.

Any ideas? Is my tail servo suspect???

Vibe screen cap and settings file attached...

Hello,

first from all I recommend to increase piro consistency for Gaui to approx 170, then you can decrease your gyro gain until oscillations will disappear.
If your Gyro Gain will be too low (normally it is around 60%) then you can put ball linkage back to 10mm.
Also decreasing Rudder Delay to 0-2 may help you.
What is your Rudder neutral settings? For Gaui it is fine to configure 3-4° when servo horn is at 90°.

Make sure your throttle curve is proper and RPM are constant else it will be much more easier to get into tail wag.

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Spirit System developer

My rudder neutral is set per the Gaui manual which is slider control arm at 90 with servo at 90. Not sure what that works out to in degrees, I have not bothered to measure it. I will give the settings you recommended a try and report back.

Thanks for the quick reply!

OK, you are welcome.

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Spirit System developer

Greetings,
If you have tried everything and are still having troubles, try this mod I found the other day while looking for parts. I haven't tried it myself, but hey worth a try?
http://www.infinity-hobby.com/main/news ... sk_id=1725

Thanks for posting that, I had not seen it before. I am assuming the shims are to remove play in the tailshaft? Mine had a perfect fit with regards to that, no shims needed.

So this turned out to be a mechanical issue. My tail rotor was binding but only when loaded which made it a bit tricky to diagnose. Thanks to everyone for the help.