ORIGINAL: j.duncker
This can give rise to a problem unless you use a really stiff horn.
One of the things that I do when I cross the cables (which is the only way I've done it so far) is to use ball-joints on the servo end and put one ball-joint on the top of the servo arm and the other on the bottom.
The ball joint is not on the centre line of the horn. Therefor a torque is created which will twist a plastic or weak metal horn.
This might not matter on a SIG Four Star 60 flown at training speeds but anything bigger, faster or with larger control surfaces could have problems.
I agree... I wouldn't do that on a larger aircraft. But on something this size, it works great. Any time you use ball joints, there's the possibility of twisting a weak control horn/servo arm, not just on a pull-pull.
On something larger, I would run the cables through a tube of some sort to prevent rubbing/hitting each other. The other option is to mount one side of the servo higher than the other.
-t