When an FPV drone's motor halts abruptly, causing the drone to crash, it's often a sign of ESC Desynchronization. This guide explores the causes and provides strategies for correcting ESC desyncs through adjustments in BLHeli and Betaflight configurations no mater you are using sush as 1800KV brushless motorsmall drone motor2806.5 Brushless Motor..

Understanding ESC Desync

Not every crash signifies an ESC desync. For example, a drone plummeting without spinning might indicate a failsafe or power loss. An ESC desync typically results in the drone spinning or flipping uncontrollably.

Analyzing Blackbox logs is the most effective method to diagnose an ESC desync, characterized by a motor stalling (ceasing to spin, thereby not generating lift), which in turn causes the drone to increase the motor's signal to its maximum 100%.

Without Blackbox, scrutinizing DVR footage closely can also hint at which motor suffered from the desync based on the direction of the drone's roll—the affected motor is usually the first to drop.


Causes of ESC Desync

ESC desync can arise from:

  • Motor RPM exceeding the ESC's capability.
  • Excessive electrical interference.

A high motor RPM can prevent the ESC from detecting the motor’s “zero crossing” point (commutation), and electrical interference can compound this issue. If the ESC fails to detect the “zero crossing,” it won't know when to activate the next pulse, causing the motor to stall eventually.

Addressing ESC Desync

Mitigating ESC Desync involves adjusting settings in BLHeli and Betaflight. Not all adjustments may be necessary simultaneously, but a combination thereof could resolve the problem.

First and foremost, ensure a low ESR capacitor is soldered to your ESC’s power input to minimize electrical noise, which is often a primary culprit.

BLHeli Adjustments:

  • Rampup Power (or Startup Power): Opt for a lower setting, such as 0.125 in BLHeli_S or 12% in BLHeli_32. Increase the rampup power incrementally if the motors stutter upon arming, until the motors initiate smoothly without inducing desync.
  • Demag Compensation: Increase to high to enhance the drone's ability to recover from desync episodes, though it might slightly impact performance.

Adjust these settings only if you encounter desync issues.

Betaflight Adjustments:

  • DShot ESC Protocol: Switch to DShot if not already in use.
  • Motor Idle Throttle Value: The standard setting is 5.5, which may be too low for smaller quads. Consider adjusting to a higher value, such as 6.5 or 7.


By following these strategies, your ESC Desync issues should be resolved, paving the way for fine-tuning your quad with these 10 easy steps

Enjoy your flight!

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