The motor's abnormal sound causes jitters during flight

Causes:

1. There's an issue with the flight controller's gyroscope.

2. There's a problem with the motor's dynamic balance.

Solutions：

1. For drone flight jitters - Use an 8-bit ESC and flash with the Bluebird firmware to enable bidirectional Dshot. （How to enable bidirectional dshot (by RPM filter) in Betaflight configurator?）

2. For 32-bit ESCs, you can first set both 'PWM Frequency High' and 'PWM Frequency Low' to the lowest value in BLHeli32. Then, based on actual flight performance, adjust them upward one step at a time simultaneously.

3. Reduce gyroscope interference.

Many frames come with press-fit nuts, but there are indeed quite a few that don't. It's relatively risky if the bottom of the ESC isn't elevated since the silicone pad is quite soft. During intense maneuvers or in the event of a crash, the deformation of the silicone pad is much greater than one might expect. It's strongly recommended to elevate it with hexagonal nuts. This can also help to reduce gyroscope interference. (Chris Rosser has tested and verified this point.)