Hi everyone,
I’m running into a complex issue with a dual-motor setup and I’m hoping someone from HobbyKing support or an experienced user can help analyze this.
Setup details:
Motors: 2× Turnigy SK3 5055-430KV (identical batch)
ESCs: 2× HobbyKing Platinum Pro 100A (latest firmware via LCD programmer)
Battery: 6S 5000mAh 45C LiPo (single pack, parallel power split)
Propellers: APC 15×8E (matched and balanced)
Application: Twin-motor fixed-wing aircraft
Cooling: Adequate airflow, ESC temps measured via telemetry
Problem description:
After ~3–5 minutes of flight at ~60–70% throttle, one motor intermittently:
Loses sync briefly (audible RPM drop),
Then either recovers or triggers ESC thermal cutoff,
While the other motor continues running normally.
Key observations:
ESC temperature at cutoff is reported ~72–75°C (below rated limit).
Battery voltage sag is symmetrical and within expected range.
Swapping ESCs and motors left-to-right does not move the problem — it always happens on the same side of the airframe.
Signal wires are equal length and routed away from power lines.
BEC disabled on both ESCs (external BEC used).
What I’ve already tried:
Lowering motor timing (Low → Medium → High)
Changing PWM frequency
Recalibrating throttle endpoints multiple times
Replacing signal cable
Adding additional bulk capacitors near ESC input
Could this be caused by ground reference differences, EMI induced by airframe layout, or a subtle interaction between ESC firmware and back-EMF under partial load conditions?
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Given your data, I’d bet on either:
The fact that swapping hardware doesn’t move the issue is the strongest diagnostic clue.
@animal craft I've faced similar issues with desync as well! I found that checking the ESC settings was a game changer. Did you get to adjust the timing settings on your HobbyKing ESCs?
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Fiddling with RC gear can certainly be frustrating! It sounds like you've been pretty thorough already. Beyond the usual calibration, I wonder if the ESC's throttle range is fully compatible with your transmitter's signal. Maybe try adjusting the travel adjust settings on your transmitter specifically for the throttle channel, pushing it beyond 100% in both directions, and then recalibrate. Perhaps it is related to contagem de dias a partir de uma data. Good luck sorting it out!
That's actually an interesting angle I hadn't considered, I've been so focused on hardware that I didn't think about the transmitter's endpoint limits potentially clipping the signal range. I'll definitely play with the travel adjust settings and recalibrate to see if that cleans up the sync issues.
Appreciate the suggestion! I've also been tinkering with some 3D printed parts for better ESC airflow, and this guide on https://prusaslicer.cc/ has been super helpful for dialing in the cooling ducts. Hopefully between the radio tweaks and better airflow, I can keep it in the air longer.
Grateful!
I've been troubleshooting a similar desync issue, and sometimes you just need a mental break like playing Pasjans Pająk to reset. Have you double-checked the ESC firmware versions and throttle calibration on each unit individually?