Originally Posted by eagle777
As the slider reaches the center of the tail rotor, the arm pushes the slider ball back more to the rear of the heli, pressing against the rear of the inside of the arm (which is locked in a vertical position). The slider ball can tip a bit normally, but this arm is making it tip too much.
I see what you're saying now - the arm is effectively too long, so at the centre of travel the linkage ball is capsized to the point where it binds against the arm. If you had a photo in side view, it would show the slider at quite an angle to the vertical.
Maybe you could find another ball link that works, or even grind down the base of a ball link to prevent the binding.
Odd (and very annoying) that there should be a whole 2mm of difference in the tail casings!