This is what I'm going to do on my .25 size fun fly to try to get the pull-pull even better.... I'm going to use a little ackerman...

I'm going to drill a little hole between the holes in the servo horn.

Whaddya think?

i know on my race car that changes the angle of each wheel on stearing, as they follow a diffrent track, but what advantage is it going to do for a rudder? it looks a bit like double differential as per ailerons... but..... ummm pls tell

Check this out for a complete description of ackerman:
//members.cox.net/bdfelice/

so... are we going for a better netural? i always hate how they flap a bit in netural. reading through i thought at first this was to cure the slack line thing, but obvisiouly not lol the only time the slack line is a problem, is when the plane is no longer moving forwards, spins and things... but if your not moving, who cares lol

I'll let you know how mine comes out when I get it finished.

Paul, there are several manufacturers of servo arms that are wheels instead of a conventional arm. I've used them and really love them. I believe that the ones that I used in the past is put out be Hanger 9. The cable is looped around the far side of the control surface and is fastened in the center of the circumference of the wheel away from the control surface. I really liked them. The ones that I used were Aluminum. I don't think that there was much, if any, weight difference between them and standard plastic arms, though it may be more important to you on a 25-size

Kevin why do you liike the wheel better for the pull pull?

You don't get the slack in the one cable while the other is pulling, thence I see better response when you transition the control surface up to down and vise versa. There is less stretch in the cables, actually it just takes longer to stretch the same amount also. Try them, you'll see what I'm talking about.

By the way Bobby, where do you fly in Greenville? I am with the BSRC (Black Sheep Radio Control) Club.