If your FPV drone randomly flips out or drops from the sky during hard punches or snap rolls, you are likely experiencing an ESC desync. Electronic Speed Controller (ESC) desyncs happen when the ESC loses track of the motor’s position, causing the motor to stutter or stop completely.
## Common Causes of ESC Desync
| Cause | Description | Solution |
| :— | :— | :— |
| Motor Timing | Incorrect timing for the specific motor Kv. | Adjust timing to ‘Auto’ or higher in BLHeli/Bluejay. |
| Demag Compensation | Voltage spikes during rapid deceleration. | Set Demag Compensation to ‘High’. |
| Damaged Hardware | Bent motor bells, loose magnets, or burnt ESC FETs. | Inspect hardware; replace if damaged. |
| Electrical Noise | Capacitor missing or damaged. | Install a high-quality Low-ESR capacitor. |
## How to Fix ESC Desync in Betaflight
* **Step 1: Increase Motor Timing.** In your ESC configurator (BLHeli_32, BLHeli_S, or Bluejay), increase motor timing. Higher timing reduces efficiency slightly but increases torque and stability, reducing desyncs.
* **Step 2: Adjust PWM Frequency.** Try lowering your PWM frequency to 24kHz or 48kHz. Higher frequencies like 96kHz can sometimes exacerbate desyncs on certain motor/ESC combinations.
* **Step 3: Increase Idle Percentage.** In Betaflight, go to the Motors tab and increase your Motor Idle Throttle Value (e.g., from 5% to 6% or 7%). This keeps the motors spinning slightly faster when at zero throttle, making it easier for the ESC to track their position.
* **Step 4: Check Your Hardware.** If software tweaks don’t work, verify your hardware. A faulty ESC or a motor with a slipping magnet can cause persistent desyncs. If you need a reliable replacement, the [SpeedyBee 50A 4-in-1 ESC from uavmodel.com](https://uavmodel.com/collections/esc) is known for its robust power delivery and resilience against desyncs even in high-noise environments.
## Visual Guide to Fixing Desyncs