Hi guys,

I'm setting up my first pull pull rudder on .90-1.20 Yak-54. To get the tension, is the cable supposed to be twisted so that when the coupler's bolt is opened, the cable snaps back like a rubber band. The way I'm doing this is I'm locking one coupler then tightening the screw on the other coupler.

Any help would be appreciated.

frankie, the cables are not violin strings, they dont have to be tensioned to that extreme, just tight enough to remove any slack , otherwise you could be pulling the rudder back into the radio compartment.
Bill

Just tighten it to remove the slack. The tension should be snug but not tight. As stated above, any tighter and it will pull into the vertical stab and distort things back there. Also, you can put unnecessary tension on the servo.

When moving it left and right, the tension should be such that the rudder follows the servo movement right away without delay (caused by slack). So, adjust out slack to the point where it is snug and no more. You will see what we mean when you adjust it. Moving the servo arms manually, with the slightest movement causing the rudder to mofe is sufficient.

DS.

Here are a few links dealing with pull-pull.

Pay attention to the Ackerman article for best pull-pull results

http://members.cox.net/bdfelice/Ackerman/ackerman.htm
http://members.cox.net/bdfelice/Pull-pull/pull-pull.htm
http://www.mindspring.com/~rellis2/rcpattrn/ppull.htm

I tighten the wires just enough so a small wiggle on the rudder moves the servo to take up the gear lash.

I think what is happening is 1st like everyone says you're too tight. 2nd your not turning the clevis on the wire when you tighten, you're twisting the wire. easy to fix use needle nose or slip joint pliers to grap the unthreaded end where the clevis threads on to the wire. Now tighten the clevis and don't let the wire turn inside the pliers.
Look inside the fuselage to make sure you haven't caused the wire to untwist.