I notice that one of my servos makes a humming sound,is there a way to stop this or is it normal? regards

just make sure it is not binding.... digital servos are more prone to this

Tap the control surface in both directions. If the humming stops, it's noting to worry about as the engine vibrations will do the same thing.

<div>First of all, is it a digital servo?? If it is a digital it's normal for it it hum when sitting idle.

If it's not a digital servo.</div>Do as Minnflyer said. If it still hums try disconnecting the control linkage from it and see if it still hums. If it stops humming when you disconnect the control linkage then you have something in your linkage/control surface that is binding and putting pressure on the servo.<div>
</div><div>Ken</div>

Yes It is digital,thanks