been chasing this for a few days now and its driving me insane. quad is a 3.5inch ultralight build, running a whoop-style FC with the ESCs integrated on the same board. basically what happens is motor 3 (rear left on my setup) will stutter or hesitate for like half a second when i push throttle from low, especially cold. once its warm and ive done a few packs it seems mostly fine but sometimes still does it mid-flight which is sketchy.

ive already tried swapping props, reseating the motor connector, and reflashing the ESC firmware. also re-did the pidtune thinking it was maybe an overshoot thing but no dice. the motor itself spins smooth by hand and doesnt feel hot after flying. its not throwing any errors in the blackbox that i can see ? well actually i havent fully gone through the blackbox log yet, i probably should do that first before posting but here we are lol

anyone recognize this kind of symptom? wondering if its a dying motor, bad solder joint somewhere, or something on the ESC side of the board. the whole integrated ESC thing makes me nervous because if its the ESC its basically a full board swap.

go look at the blackbox first seriously, motor desync has a pretty recognizable signature and youll see it immediately if thats whats happening. look for the RPM on motor 3 dropping while the others track normally, should be obvious if youre filtering the right channels.

that said the cold-start thing does sound a bit like a marginal motor or a connector issue. ive seen this exact thing on a twig-style build where one motor had a slightly corroded pin in the JST connector, looked fine visually but was dropping resistance when it heated up. wiggling the connector while spinning actually reproduced it on the bench. worth trying that before you condemn the board.

could also be a slightly bent motor shaft from a crash you maybe didnt notice at the time? i had stuttering on one motor for weeks on my 3inch and it turned out the shaft had like a very tiny bend, not enough to feel obviously wobbly but enough that under load it was causing weird things. swapped the motor and problem went away immediately. motors on small builds are cheap enough that honestly just trying a replacement is sometimes faster than diagnozing the exact cause lol