so i binned my 5inch pretty hard into a concrete wall at the track last weekend, one of those moments where you just know immediately it wasnt good. m2 arm looks fine visually, no cracks i can see, but when i spin up on the bench theres this low frequency wobble coming from that corner that wasnt there before. props are new, ive swapped them twice to rule that out.

thing is the motor itself spins freely by hand, no grinding, no obvious bent shaft. but in betaflight the motor tab shows m2 pulling noticeably more amps than the others at the same throttle input which seems like a bad sign. wondering if anyone has dealt with this where it ended up being the arm flex rather than the motor itself, because id rather not drop money on a new motor if the arm is just slightly tweaked and transferring weird vibration.

running 2306 2450kv motors if that matters. frame is a tpu arms type so i guess it could have absorbed weirdly.

the amp draw difference is the tell imo. ive seen motors that feel fine by hand but the stator gets slightly warped or one of the windings takes a hit and it just works harder than it should. tpu arms can hide a lot too, they flex so they dont crack but they can deform just enough to throw off the motor mount angle and that will absolutely cause low freq wobble. honestly id pull the motor, mount it on a known good arm or just hold it in your hand and run it up on the bench and see if the wobble follows the motor or stays in the frame.

if the wobble follows the motor its toast, if it goes away its the arm. takes like 10 minutes and saves you the guesswork.

had almost the exact same thing happen with my quad a couple months ago, different motor brand but same situation. mine ended up being a slightly bent shaft that i couldnt detect just by spinning it by hand because it was such a small bend. only way i found it was putting a prop on and watching from the side while it spun slowly ? you could see the prop disk wasnt flat, had this slight wobble. replaced the motor and it was completely gone. the current draw thing lines up with that too because a bent shaft creates uneven load.