ESC Electronic Speed Controller

The ESC controls what your motors do based on your commands from the transmitter. The speed controller essentially speeds up or slows down your motors allowing you to change directions.

The quadcopter kit I first purchased came with Emax SimonK ESC’s.  I don’t know enough about the esc’s to really say anything about them except that they work but they are crappy. There is a trick with SimonK, I attempted several times to calibrate them but couldn’t get it working, they just kept beeping.  I discovered through some research and some help from YouTube user Channy that from the time you plug in the battery during the calibration steps you have 2 seconds or less to lower the throttle in cleanflight.  It seems like a very short 2 seconds but nonetheless you have to be fast or you will go into programming mode on the ESC. My second quadcopter I upgraded to 20amp Blheli ESC's. Blheli is the firmware loaded on the ESC, it is much better than the SimonK firmware and much easier to update. The higher the amperage that your motors will draw will affect the size of ESC that you purchase. You can't go wrong if you just get 30 amp ESC's to begin with. On a racing drone you will not need higher than that.

I've ordered a new set of ESC's which are 28 amp, I will install those on my racing quadcopter and place my 20amp ESC's on a large aerial photography quadcopter that I am building.