wjcalhoun

I've used the 6-32 threaded rod / washer / hex nut system for pull-pull as well, and it works well. Coated braided steel fishing leader doesn't rust, and generally is 30#-75# test - way more than any servo will generate.

I agree that bending the bolts or rod is not ideal. I put #6 hardware on the bolts, and adjust the positioning of the #6 rod so that the pivot point is EXACTLY on my hinge line, giving square geometry, and no change in tension with deflection. Obviously, the distance between pivot points on the rudder has to equal the distance between the pivot points on the servo arm.

Alternatively, if the pivot point is behind the hinge line, you can make the linkage at the servo end such that the pivot point is exactly the same distance aft of the center of the servo as the pivot point is aft of the rudder hinge line. So long as the geometry is square, the tension will not change.