Emax rs2205 fire

[Stubb-z]

Just had one of my 4 emax 2205's spark, smoke, and then burst into flame as I was setting up a new build in betaflight!    - never experienced it before - deffo brown trousers time!
 
Is this likely to just be a dodgy motor do you think - or will the esc be at fault too?
Anyone know if there is a test to check if the esc is OK?

I'm still in shock a little as it happened in the lounge with the kids watching tv next to me - could have been a nasty one!

[murpia]

I have has ESCs take out motors, but never the other way round. It should be obvious though as the ESC always stinks of burnt electrics afterwards...

[ched]

It does sound a bit weird to have a motor catch fire when setting up. I assume that no bolts are touching windings? The only other thing I could think off is the pids are way off and causing the motor to overheat, but I would have thought that would not happen on a setup more on first flights.
Let us know what you find.

[murpia]

Bolts touching windings causing a short could cause a fire when the BLHeli beeps occur on power up...

[Stubb-z]

So - taken the motor casing apart and all is pretty badly burnt inside. Nothing obvious and bolt length is bang on - nowhere near the windings at all so no short there. 
Replacement motors arrived this morning and have soldered new one on.
POOF more magic smoke. 

[ched]

So - taken the motor casing apart and all is pretty badly burnt inside. Nothing obvious and bolt length is bang on - nowhere near the windings at all so no short there. 
Replacement motors arrived this morning and have soldered new one on.
POOF more magic smoke. 

Sugar. Only think I can think of is ESC is providing batt voltage across windings and heating up too much and melting! That said I would have thought the esc would have died and melted stopping them providing current.

I feel your pain. I destroyed 2 x 4in1 esc and a set of 4 motors before I realised the 2 of each motor bolts were 1mm longer then the others! Guess which bolts I measured and checked!!!! I even checked continuity between frame, batt leads and motor windings before powering on each time!!!!!!

[murpia]

Replacement motors arrived this morning and have soldered new one on.
POOF more magic smoke. 

Like I said before, a bad ESC can short out a perfectly good motor. I have had it happen a couple of times.

In an ESC there are 3 high-side FETs and 3 low-side FETs arranged as 3 half-bridge circuits. If one high-side of one half-bridge and one low-side on a different half-bridge fail shorted, they will dump full battery current through one phase of the motor. It's possible that the ESC will not 'smoke' before the motor does, sounds like this has happened to you.

Only if both the high-side and low-side of the same half-bridge fail short, will the ESC smoke without damaging the motor. So the odds are 2 out of 3 that the motor gets smoked and 1 out of 3 that only the ESC does.

Cheers, Ian

[Stubb-z]

New Esc ordered - will keep you posted!
(May need a second mortgage before this bloody build is finished!) 

[ched]

I know what you mean. The motors and esc I destroyed were more expensive than the SkyStar Ghost Rider Big Pick X120 kit that included motors, exc, frame, fc, camera, vtx, props, etc!!!
Build thread here: https://www.multi-rotor.co.uk/index.php?topic=24116.msg218551

[Stubb-z]

New motor and esc seem to have done the trick - all good now on that front - just struggling to get anything from the rx on the board now though!