Listen to what your plane is trying to tell you!! (ESC Fire)

CustomRCMods

Elite member
Was recently flying my FT Mini Vector, (running a SunnySky 2207s 2100kv paired with a 6x4.5x3 prop). The ESC was a ZTW 30a, usually plenty for most any park flyer in terms of amperage capacity.

I noticed multiple throttle cutouts in my first pack, but thought nothing of them and let the electrics cool for about 10 min while I flew other planes. Came back for a second pack, and there was more frequent cutouts, until finally I had no throttle response and had to glide the craft back to earth for a dead stick landing.

Upon touchdown, I heard the ESC re-initialize (tones, etc.) before hearing a POP, and I quickly pulled off the nose come and was greeted with flames and smoke billowing from the fuselage. Thankfully a few stomps was all it took for the flames to subside, but the damage had been done and several other components (battery, rx, etc) were mounted close to the ESC, so they were charred as well.

Thankfully I tested all the components after the fact and nothing besides the blown ESC was damaged in any way other than cosmetically. I was concerned for the battery but I observed no cell puffing or other physical complications, and the cell voltage remained balanced and constant over multiple days where i let it be.

Moral of the story: Listen to your plane! it’s telling you things, things I just rubbed off even when I knew the significance of them. Also, be prepared. the few moments I saw flames, I felt helpless in the middle of a huge field, no means of firefighting in sight, so it might seem silly, but ask yourself, what would I do if my plane caught ablaze??

As for the Vector, the charred airframe is in the trash, I’m planning to rebuild another one this week. I learned I definitely need to prop this guy down, gonna start on a 5x4 and work my way up from there measuring my temps.
 

The Fopster

Master member
Had my first motor/esc "thermal incident" last week. It was a but rough when starting up but seemed OK once it was running - like you, I assumed it was OK, and like you - it wasn't!
:)
 

Merv

Site Moderator
Staff member
It’s always a good idea to check the temp of everything after each flight.
ESC’s are consumable products, they don’t last forever, they eventually wear out. I have no idea why they go bad when they do.
 

Piotrsko

Master member
ESC’s are consumable products, they don’t last forever, they eventually wear out. I have no idea why they go bad when they do.
Mosfets in parallel which dont share well unless preci$ion matched. Just ask Otmar why
Otoh, considering the crap receivers out there, I could see why you might think it was a LOS or other minor irritation.