On my Giant Sudokhoi, I've got two hitec 605 servos on a dual pull-pull elevator. The servos seem to be moving in an almost identical rhythm.. the movement seems fine. The problem is that I've got quite a bit of tension on the pull-pull lines and the 'return to center' isn't exact... If I have less tension in the lines, will that alleviate the problem? I can see the surface sticking especially on landing when the plane is porpoising on the approach... the elevator sticks just a bit up as a I dial in up and vica versa.

Any suggestions? Does this make any sense?

Thanks,
Juhan

It does to me..I had the same symptoms, and loosing the cables just a tad fixed it.

I have found that with the 605's any tension on the output shaft will cause them to not center so well..

Try a different servo on one side just to see if there is any difference.

I've noticed the same thing with some 605's that I have in a plane.

I'm wondering if the holes on your control horns on the elevator aren't lined up with the hinge line exactly... If the holes are forward of the hinge line, the lines will get tighter thru the movement. If the holes are behind the hinge line, the lines will get looser thru the movement.

My guess is you can loosen the tension a little and the problem will go away.