Hello @Alex-Kushleyev ,
Thank you for getting back to us.
Please find below a detailed summary of the failure scenarios observed during our recent flight testing activities. We would appreciate your assistance in analyzing these events and identifying any potential root causes.
System Configuration
VOXL 2 → Flight Controller V2 → ESC
Motor: T-Motor F60 Pro LV, 2020KV
Propeller: 5-inch Three-Blade Propeller
Battery: 6S, 5000mAh (21700 Cells)
Scenario 1 – VOXL FPV ESC Failure
During flight, the drone was operating normally when the rear-left motor suddenly stopped, causing the aircraft to lose stability and topple.
Following a system reboot, the affected motor exhibited abnormal behavior:
The motor would begin rotating briefly.
It would then stop unexpectedly.
This cycle would continuously repeat.
The same behavior was reproduced while running the ESC spin.py test utility.
As part of troubleshooting, we:
Updated the ESC firmware to the latest available version.
Applied the recommended parameter changes.
Repeated motor and ESC validation tests.
However, the issue persisted, and no improvement was observed.
Scenario 2 – VOXL FPV ESC No Longer Initializes
In a separate flight test using a replacement ESC, the drone was in a stable hover when the front-left motor stopped unexpectedly, causing the aircraft to topple.
Following the incident:
The affected ESC no longer initializes correctly.
During power-up, the ESC LEDs briefly illuminate and then turn off.
The ESC does not appear to complete its startup sequence.
Troubleshooting performed:
Connected the ESC directly to a computer.
Attempted to establish communication and detect the ESC.
Performed multiple power cycles and reconnection attempts.
Unfortunately, the ESC could not be detected, and communication could not be established. The terminal output associated with this issue was shared previously in our earlier correspondence.
Scenario 3 – Third-Party ESC Evaluation
To further isolate the issue, we replaced the VOXL FPV ESC with a NeutronRC X-CLASS 4IN1 ESC V2 (3–8S, 70A) configured using the DShot protocol.
During testing, we observed the following:
ESC temperature increased rapidly, reaching approximately
80°C to 90°C within two minutes of flight.
One motor would subsequently stop during flight.
The aircraft would lose stability and crash.
During or immediately after impact, the ESC appeared to reboot.
Following the reboot, the system would operate normally again.
This behavior has been consistently observed across five separate flight tests, with each flight resulting in a similar failure sequence and crash.
Additional Observations
While reviewing the available flight logs, we observed elevated ESC temperatures:
General ESC operating temperature ranged between
75°C and 88°C during the affected flights.
ESC(0) reached a peak temperature of approximately
88°C.
During earlier flight tests under similar operating conditions, ESC temperatures typically ranged between
60°C and 75°C.
Installation and Thermal Management Details
The ESC is installed inside a closed enclosure with the following thermal arrangement:
Bottom-mounted aluminum heatsink.
Thermal interface material between the ESC and heatsink.
Side walls constructed from aluminum structural members.
Despite the presence of thermal conduction paths, the elevated temperatures observed during flight raise concerns regarding thermal dissipation and potential thermal shutdown behavior.
Flight Logs
Log File:
https://drive.google.com/file/d/1wxv7VZub4-7onK6YdgcJ8kSpGhpZ40mY/view?usp=sharing
Note: Access approval may be required to view the file. If the link is inaccessible, please send an access request and we will grant permissions immediately.
Given that similar symptoms have been observed across both the VOXL FPV ESC and a third-party ESC platform, we would greatly appreciate your guidance on:
Potential root causes of the motor shutdown events.
Whether the observed temperatures are within acceptable operating limits.
Recommended diagnostics or logging parameters to further isolate the issue.
Any known interactions between the motor, propeller, battery, and ESC configuration that could contribute to these failures.
Please let us know if any additional logs, hardware details, configuration files, or test data are required from our side.
Thank you for your continued support and assistance.
