Strange servo behaviour
 

Goodday,

i have a pilot rc predator with mks 737hv servo's. Power distributions is via a powerbox professional. All the servo's are powered by the powerbox as well as the flaps servo's where the problem is. Radio is a futaba t14sg with futaba rx. The problem: the flaps move over time. At startup the flaps are not completly centered but after a minute or so it is centered. Control is via a 3-way switch for Up-take off-landing configuration. And it is strange only the flap servo's will move over time and at powerbox startup it is not centered, even after setup to center the flap servo's and recycle power. What can cause this slowly servo movement?

best regards,
christiaan

Put the RX on the bench and hook up a basic system with battery, the flap servo (s) and the Tx. Power this up and watch. See if the same symptoms occur. If nothing happens, add one more item from the plane and test again. Keep going until the problem shows itself. Last item added is probably the culprit. I expect you'll find it sooner rather than later.