Make sure the ESC is up to the job too. Some say only to use 3 servos on 3 cells or 11.1 volts. Found out the hard way. the servos will draw more amps than the ESC is rated for and overheats and shuts off to protect itself and you have no control whatsoever. As soon as it cools down in a few seconds, it turns back on again. One check is to rotate the right stick and wiggle the rudder back and forth and feel the ESC for heat. Mine got to hot to touch, then shut off. Worse in the air as the surfaces have a load on them. Read the bec amp rating when when you buy the ESC and get one with about 2 amps and able to handle 4 servos on 11.1 volts