Normal in stabilize, but vibrates in loiter

I am configuring tradheli by installing pixhawk 5x on trex 470. And FC version is 4.2.0-beta3

I had my first flight today. It flew normally at stabilize and althold, and tested the loiter with pleasure.

However, in the loiter, a high vibration occurred on the yaw axis, and I could not find the reason.

If it is a PID problem, I thought the same symptoms should appear in stabilize and althold, but I couldn’t find any other cause.

I am attaching the flight log (0018 = stabilization & altold, 0019 = loiter) on the following link, so I would appreciate it if you could help me.

https://drive.google.com/drive/folders/1MEWAlYt1T8I8BOWHT8k3RLjKhJ9PKZtm?usp=sharing

I check yours logs and the vibrations in general are very high (special x -axis) you should dump it. I recommend you to use 3M foam ~5mm thickness, and enable the harmonic notch filter.
Looking to your Bat and Curr logs, when you switch to Loiter, seems that your external governor is doing something different in this mode. Maybe the motor rpms are going back and forward, making the tail vibrating by following the shaking of the motor. I am not familiar with external governors but I see your issue is happening only when your battery is with low voltage and maybe it was just a coincidence, becaue you switched to Loiter mode only when you were running low battery. Maybe you have an issue with your external governor running low voltage and not with Loiter mode. Try the Loiter mode with a full charge battery.

Thank you for your reply.

I found that the cause of the X-axis vibration was due to abnormal vibration in one of the swash plate servo.

Harmonic notch filters, fully charged batteries, and servo replacement are likely to be done right away.

I will answer the results after applying the above… Thank you!

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I didn’t have time to test it because I was defending my thesis…

After recent tests, it seems that the abnormal vibration of the swash servo was causing the vibration in the yaw direction.

The problem with the swash servo was that the PWM wires were bundled together with the signal wires from the sik radio, causing noise in the signal.

This seems to have been solved!