ORIGINAL: Rendegade
The pulley system, to me seems to be a bit of false benefit.
let me explain with the power of pictures!
As I see it, having a set up the same as JAS's (which is the way I do it) seems the most logical. to fixed points on the rudder and the servo arm. As the arm travels the lengths stay the same right?
With a pulley, they don't, calculating the distances between the horns mathematically, the long side would need to GROW to keep the tension on the lines the same, so essentially what i think occurs is the tension on the cables is balanced, but the OVERALL tension increases, which I'm not so sure is a good thing.
Anyway, some food for thought.
It looks to me like the distance between the servo wheel and the rudder horn would change an equal amount on both sides (and at the same rate), as long as the rudder horns are centered around the hinge axis. What I believe the effect of the pulley would be is to create more sensitivity near the end points - it would take some of the sinusoidal response out of the system and make it more of a linear response. The cable should remain the same tension throughout the full range of motion.