Hi,
I’m trying to understand a stability issue on one of my 10” builds and would appreciate some help or ideas.
Setup:
FC: MatekSys H743-SLIM V4
ESC: SEQURE 4-in-1 (AM32, DShot600)
Motors/Props: same as before
Battery: 6S (voltage stays stable under load)
Firmware: ArduCopter 4.6.3
Frame: 10" quad (X)
I’ve flown this exact ESC, motors and props before on Betaflight, and it worked perfectly.
The only thing that changed is the FC and firmware.
The problem…
On low and mid throttle the quad flies fine.
When I increase throttle more aggressively it begins drifting/leaning slowly to one side and eventually can’t hold level.
There are no oscillations, just a steady lean that gets worse as power increases.
What I’ve checked
Props: correct rotation, no damage
Motors: smooth, no bent shafts
Frame/arms: straight
ESC + wiring: same hardware that worked on Betaflight
What the ArduPilot log shows
VIBE: ~10–15 (normal)
Voltage: stable during full throttle
RCOU:
One motor repeatedly hits ~1949 µs
The others stay around 1400–1600 µs
So the FC is driving one motor almost to its limit while the other three are far below it, which lines up with what I see in flight.
What could cause this kind of motor saturation on only one corner when the same hardware worked perfectly on Betaflight?
br,
Axel
