When this applies

The 3D drone preview on Betaflight's Setup tab slowly rotates or drifts (usually on the yaw axis) while your flight controller is sitting perfectly still, and you are wondering whether the gyro is faulty.

Short answer

Almost always, no. This is normal behaviour, not a sign of a faulty gyro.

Why the preview drifts

The 3D model is a live visualisation of the raw data streaming from the flight controller over USB. It does not apply the filtering and correction the flight controller uses in flight.

Pitch and roll are continuously corrected by the accelerometer, because gravity gives them an absolute reference, so they stay stable. Yaw is different: unless your board has a magnetometer (compass), there is no absolute heading reference.

Every gyro has a tiny amount of bias, and with nothing to correct against, that bias accumulates and the model slowly rotates even though the board is dead still. Betaflight's documentation notes that a compass is what determines heading in 3D space: https://betaflight.com/docs/wiki/app/setup-tab

For the same reason, the yaw heading resetting to a new value on every reboot or replug is also normal without a compass.

When the 3D model IS telling you something is wrong

• The model does not move when you move the board, or moves on the wrong axis (tilting forward shows as a roll). This points to an incorrect board alignment setting, not a faulty gyro. See Betaflight's board alignment guide: https://betaflight.com/docs/wiki/guides/current/Flight-Controller-Orientation

• The model spins rapidly or erratically while still. That can indicate a genuinely noisy gyro, but confirm it with the raw sensor data below.

How to actually test your gyro

The definitive check is the gyro's raw output in the Sensors tab, not the 3D model. Enable Expert Mode, open the Sensors tab, select the gyroscope view, set the scale to 100, and keep the board completely motionless. A healthy gyro shows a smooth, flat graph. A faulty one shows noise or movement even though nothing is moving.

Our step-by-step guide with screenshots, including how to view the raw IMU data: https://help.unmannedtech.co.uk/portal/en-gb/kb/articles/flight-controller-has-a-bad-faulty-gyro-how-to-test-in-betaflight

If your gyro graph does show a genuine fault on a board purchased from us, send our support team a short video of the graph and we will be happy to help.