servos random movements


New member
I'm setting up a new FT plane, using a Spektrum AR637 receiver, a Eflight 40 amp ESC, and several different 9G servos. The throttle and motor control is fine. Spektrum brand servos seem to behave normally when connected to any channel, aileron, elevator, or rudder. But I have tried two different FT branded servos and 3 different Arrows branded servos on the elevator and rudder channels, all of which make random rapid movements and only sporadically respond to transmitter input. I have tried factory reset of the receiver, re-binding, and switching which channels control which servos. Should FT and other brand brand servos work with a Spektrum receiver? Could I just have multiple bad servos? Is there a problem having different branded servos connected to the same receiver? These random movements are not AS3X "fluttering" they are very pronounced random movements with the plane stationary.


Active member
I don't know the AR637, but its product page says that it has "Standard servo connectors." Normally when my servos jump all over the place (or don't respond at all) it's because I have them in backwards (the outside pings signal and neural are easy to have backwards. Did a little googling too and it might be because of a weird servo frame rate - I found several mentions of people who had to change their servo frame rate. One fixed this by "unlocking" their reciever (which seemed to be PC based) and someone else changed a setting on their radio to make normal servos work. I don't own a Spektrum radio, nor an AR637 so I can't do much other than suggesting checking your polarity and researching "servo frame rates" for your receiver.


Site Moderator
Staff member
Sounds like a bad electrical connection. You might try wiggling the pins & wires to see if it makes any difference. If you can isolate the problem, it can be fixed.


New member
Figured out that this was a bad receiver. Might have been the electrical connection from servo to receiver, but the problem happened the same when the servo was plugged in to different ports on the receiver. I replaced with a new receiver, problem solved.