I have purchased four S9351 servos from Tower back in Feb 2006.

I have jsut now gotten around to installing them in a airplane.

Problem is that the centering is not good. Most of the time when the control is returned to the center position the servo is forcing a rapid oscillation. This keeps going until I touch the control surface. Then it quiets down till moved again. These servos are brand new and should not give this type of problem. Can you please explain what may be going on here?

I wanted to fly the plane this weekend but now it seems like I cannot till this problem is fixed.

Thanks

Please check your connectors. Lots of times, dirty connectors can cause the behavior you're seeing. If the oscillation stops when you have no load upon the servos, then you're OK. Digital servos will tend to "hunt" when they have little or no load upon them because the geartrain has to have a little bit of slop in it or it will wear prematurely. The tight deadband of the digital circuitry is what makes the servo try to find a center, and the little bit of slop in the geartrain prevents getting a solid center when there's little or no load upon the servo.

The air loads should quell the chattering you're seeing.

I'm having the same problem. I openend one of mine because I noticed a little slop in the gear train.
I moved one of the gears to a diffrent position and the problem stopped.
I'm not to sure but do you think that the gears need to be replaced. My servos are new and I dont
feel like paying $33.00 x (4) for a new set of gears.
Thanks