A motor died on one of my quads. It would try to turn a few times then stop trying altogether. I swapped motors and determined that they were fine. It is either the FC or 4 in 1 ESC that had failed. I replaced the entire stack today and got my quad back in the air but I'm not sure whether to bin the ESC or FC. Any suggestions besides having to wire up different combinations (which I don't have) to see which component has failed? Or is it always the ESC? FWIW it is an older Lumenier 25A ESC and the quad is a heavy high performance 4s 3" that was probably a significant load for it. It did last a few years though

It's nearly always the ESC or motors that fail and very rarely the FC, if at all. All the FC is responsible for is sending low voltage data bits over a serial connections to command the ESC what to do. So if you've already proven the motors are fine then it will 95% be the ESC which is the cause of the issues.

Cool, that's what I imagined. And I have seen this happen with RC airplanes and it's always the ESC. So it's similar I guess.

on a plane wizhout fc, its not simular in terms of throttle signal. in a rcplane the throttle is direct, on a quad the fc does apply throttle to single motors by our throttle input according the gyro data. there is a source for issues.

i would say an fc cant destroy a motor byself, but it can help :-) if there is an issue on more than one side, on the esc or motor the fc might be able to make it worse and fail sooner by wrong commands.

a high d-term value and overreacting quad, paired with a wrong startup value can cook motor, esc and fc at the same time. mainly a the startup/rampup value is very important.
on quad which should be as fast as possible, dterm can be a quad killer. its also dterm which let us fly like we are on rails, in the end its "performance request", not available, where danger is.


betaflight devs are healthcare, the brought us that crazy nice defaults. overfiltered but pretty no danger, only very uncommon builds or very very high performance does bring work for savety use on the defaults.

we went backward, from high gyro frequency rates up to 32khz on butterflight up to 8k/8k in bf. on the escs, dshot1200 was the plan once xD
today dshot600 is high, dshot300 does match more builds with the use of rpmfiltering. same on the khz frequency, commonly 4k/4k matches :-)
i believe we went from crazy innovations to rocksolid reliable system with good versatility.