so i binned my 5inch pretty hard into a concrete pillar at the skate park last weekend, was doing a split-s too close to the wall and just misjudged the gap completely. my fault entirely. anyway the damage ? one arm is cracked pretty bad near the base, motor 3 is def toast (spins but makes that grinding/scraping sound and gets hot almost immediately), and i lost two props obviously. the other three motors seem fine when i spin them by hand, smooth with no play.

my question is really whether its worth replacing the arm and motor on this frame or if i should just grab a new frame. its a cheap-ish chinese frame, maybe $18-20 replacement cost, and a decent motor is gonna run me another $15-20 on top of that. the frame itself isnt cracked anywhere else that i can see but im a little paranoid about hairline cracks i might be missing. been flying this build for almost a year so its not like im emotionally attached to the frame or anything, just trying to be practical about it

also does anyone have a good way to check if the ESC took any damage? i was running 4in1 so im a bit nervous about the whole stack

If the arm is cracked at the base that close to where it meets the main plate, i'd honestly just swap the frame. $18-20 is nothing and you'll always be second-guessing that arm every time you go out. had the same thing happen with my reaper and flew it for another two weeks before it snapped mid-flight and took out two more motors when it hit the ground. not worth it.

for the 4in1 ? plug it in on the bench with props off and check if all four motors spin up properly in blheli or whatever you're using. if one ESC channel is fried you'll usually see it right away either as a desync or it just won't respond. you can also feel for any obvious heat spots on the ESC pads or burnt smell around specific FETs but honestly if it flew before the crash and the motor was still spinning (even grinding) the ESC is probably fine. the motor usually takes the hit before the ESC does.

yeah what he said about the ESC, just do a bench test. also when you pull the dead motor off check the motor screws and make sure they didnt strip the threads in the arm, seen that happen on cheaper frames and its annoying to deal with on a new motor install if the holes are already messed up