I,ve put together many arfs but have always had problems with the servo buzzing. I spend hours trying to figure it out without much luck. I know its pressure on the servo, but cant really fix it. Can someone PLEASE let me know what I,m doing wrong.......thank you, Dave[:@]

Digital servos humm or buzz when in static and the weight of the control surface is bearing on it. I don't worry about it. In the air, they are always moving and no ill effects are noticed. It is when they 'flutter' and hunt for center in static that I take them out for repair.

If you are NOT using digital servos, check and keep checking your batteries voltage.

If it is not a digital servo, disconnect the push rod from the servo horn, or just pull off the servo horn, and see if the rod is binding anywhere; see if there is any friction, or if you have to slightly bend the rod to reconnect it to the servo. The rod needs to move fairly freely.

You can try connecting the servo in another slot in the receiver to make sure it's not something in the radio or receiver.

As mentioned, digital servos make noise all the time.

It's usually no need for concern.

Try this...

Find the servo that's buzzing and tap it's control surface in each direction. If the buzzing stops, don't sweat it, the engine vibrations will do the same thing as the tapping you did.

Not to mention the fact that if any control surface has any trim applied to it, the air moving over it will also place a load on the servo - but then the engine is running and it's up in the air so you never hear it.

Yes all mentioned ideas are great. Don't forget the control surface, unless counterbalanced, exerts a force on the servo causing it to respond (the buzz) in order to offset the tendency of the weight of the surface to move it out of center.