When 3 month ago I was doing "Hands on" review for EMAX SimonK Series 30A ESC I was quite optimistic about them. Well, why should I not be? Quite cheap, decent quality, easy to configure. Did EMAX 30A SimonK Series ESC met expectations I was putting on them?

Simple and short answer is: no, they did not met expectations. Reason is: one of them caught fire during flight causing whole UAV to fell from 30 meters into water.

emax 30A ESC SimonK on fire

emax 30A ESC SimonK Series on fire

As you can see on the pictures above, ESC is completely burned. Both MOSFETs and electronics. How do I know it burned during flight and caused a crash and not the oter way? Thanks to Blackbox logs I have a proof that this single ESC and motor connected to it were gradually losing power before UAV crashed. Since motor and attached propeller survived without a scratch, ESC is the one to blame.

To make things worse, it was not too much load that killed it. Before crash ESCs were running at around 45% throttle. That is around 7A per ESC. Way below promised 30A.

So, final conclusion: no, maybe they are cheap and easy to use, they are not reliable! And that is the critical flaw of those ESC!