Hey!

I unfortunately crashed my drone today, and some dirt got into the motors as well as the ESC/FC. I removed the dirt and cleaned the drone. 2-3 hours later, I checked the motors in Betaflight to see if they were still functioning. I noticed that 3 out of 4 were spinning normally, but the 4th one wasn't (I had connected the battery at this point). After that, I briefly checked BLHeli32 to see if everything was okay, but the 2nd ESC was no longer recognized. I then reconnected the cables (hoping it was just a loose cable) and connected the battery again (regretting not using the smoke stopper), and as a result, my motor started smoking.[/font][/size]

Now I am quite unsure if I only broke my motor or if I also broke the esc and all other modules that are connected via soldering pads. 

… got a feeling the dirt may have caused the esc to go bad.. and in turn .. the esc caused the motor to smoke..
As me how I know….

(24-Feb-2024, 08:44 PM)Rob Axel Wrote: … got a feeling the dirt may have caused the esc to go bad.. and in turn .. the esc caused the motor to smoke..
 As me how I know….

Ahh damn... that would be tragic :/ Do you know if my other parts of the drone (e.g. the FC/Air Unit/GPS/VTX Antenna) are also broken if something like this happens?

I am not really versed in this type of fixing, I am trying my best though!

when did your motor smoke? when the startup beeps should cam up or directly when plug in?

(24-Feb-2024, 11:41 PM)hugnosed_bat Wrote: when did your motor smoke? when the startup beeps should cam up or directly when plug in?

I think it was directly when I plugged it in, I cant quite remember since I was focused on betaflight at that moment

i would suggest to disconnect the fc from the esc. check both for shorts by the multimeter.

how to mesure the esc;
https://intofpv.com/t-guide-how-to-fix-esc

Okay so multiple things:

One hour ago I desoldered my motor (that had a short? it just smoked when I plugged in my lipo) and checked all pads for continuity, none of them had one and Im quite unsure why it shorted at all (if it did, idk if the smoke means that it shorted). Another thing I noticed, I assume I had a desync mid air after checking my blackbox logs. Now I'll try to check my esc/fc again to see if all escs are getting recognized by blheli32, if not then Ill probably replace the esc. (Since the fc should still be fine)

Use a smoke stopper before powering that was back up.. I smoked 2 motors thinking my esc was ok..

Ill do that, but it should be fine since I tested it with a smokestopper after desoldering. Still gonna use it and check if all escs work (hopefully)

Escs were all recognized by blheli32, no short when i plugged in the lipo. Now I am just wondering why the motor had a short in the first place? Since I didnt change anything on the solder pads after the crash and it still had no continuity

if there is no issue by the esc, it needs to be a motor issue. melted or scratched windings, damged coating on the copper windings.

it could come from physical damage, there is an issue possible with the coating.
melted coating from heat could come from many things, not matching dterm value, filtering issue - or the most common thing a unbalanced damaged rotor.
its aslo possible that the coating took damge by heat from a blocked rotor in a crash and did fail later.

there are also factorywise faults by the winding possible.

when you are able to fly that esc again, take care about motorheat on the first flights. a little bit used rotors does help to have some spare room about filtering, if the motors doesnt heat up on used (not realy damaged) rotors, you should be save than.

Ahh okay, thanks! Ill probably re-assemble the drone after the replacement motors arrive and will do some things different this time (e.g. cable management, tuning, desync prevention) Hopefully I can get it back up with no issues. Its good that I dont have to replace the esc

You can swap another motor to the pad, test it, and that will quickly tell you if it was a bad motor or if the ESC is smoking them