I use kevlar string with straight line. I once had a radio problem when using steel wire although it seems lots of folks do not. At the rudder I use the Sullivan clevis then wrap the kevlar around tie and CA. At the servo I use a Sullivan clevis and 2-56 rod. I cut the rod at 2-3 inches and make a U or O bend. Then I loop and tie an adjustable knot so I can work out the slack. I CA the knot when tight. I can make small adjustments using the 2-56 rod at the servo then lock with the nut.

Carl