ORIGINAL: Campgems

One important thing to remember about a pull pull is that the setup has to be a parallogram. If the servo arms and the rudder horns don't have the same length between the holes, and the holes are exactly on the hinge line, one cable will go slack as soon as the servo starts turning. My first attempt was really bad, and at half movement, I had close to 1/2" slop in the rudder, even though it was nice and tight in the center.
Not true, the arms on the servo can be a different length than the arms on the servo as long as, at extreme positions, the throw on one does not exceed 90 degrees. Just use your protractor and a piece of paper to draw the extremes and you will see this is so.


Just remember that the two ends of the parallogram have to be bisected at the hinge line and at the axis of the servo output.

A tip on setting them up, After setting up the horns and the servo arm as above, the lock the rudder in the center, Center the serov, and with the clevis adjustment set for the longest length, tighten and crimp the cables. It is all but impossible to get them to tight at this step, and all to easy to get way to much slop. Now equally tighten the cables until they are tight and the servo and rudder are still in netural.

Maybe one or two more of these setups and I'll get it right the first time.[&o] I do like them when they are right though.

Don