（spirit RS）I found the problem, I removed the big propeller, 70 throttle and 0 pitch and observed that all three swash plate servos were beating violently and the servos were hot to the touch. My swash plate frequency is set to 50hz and loop gain is 65. The loop feed forward is 4. Servo GDW bls992 (8.4v/0.055sec60'/28kg.cm/333hz). The body shakes when hovering, and the log shows Cycli Ring Activated. Original double-sided tape。
how do i adjust
The elevator servo No. 2 has the largest amplitude and violent beating, followed by No. 1 and No. 3 slightly.

From the description you have shared, Could be many things from the swash setup (end points), swash gain too high or even a weak BEC(if your not connecting directly to a 2s lipo for your HV servos)

bec is a 2s direct drive power supply test with no problems, and the servo frequency has dropped to the lowest 50hz. The loop gain is also a recommended value. I don’t know which parameter to adjust.

Hello,

you can try to lower Elevator Filter.
First from all please make sure that Spirit unit is holding firmly at the model - no flexing.
Then make sure there is no connector that is bouncing to the Spirit.

Servo frequency should be set always to as high as possible. Decreasing frequency will decrease performance in the most cases.

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Spirit System developer

Not sure what model your flying but can you reduce the gain from 65 to around 55?

The problem is solved. It is indeed the jitter caused by the high lift filter value. I lowered it to 0 and it became normal. The hovering of 60 cycles is very stable. I have started debugging the tail. I would like to ask if the tail will sway when the pitch is slightly compensated during hovering. The tail compensation value is 4. Should I keep increasing the value?

The elevator jittering is coming probably from very high vibration level in elevator axis. It is uncommon, but vibration measurement will show the problem.

Revomix 3-4 is max. recommended value for the most helicopters.

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Spirit System developer