I have narrowed rudder trim down to three options.
1. Spring Bias mounted under the panel. http://www.mlblueskunk.com/Rudder_Trim_System.php http://www.aerosportproducts.com/ruddertrim.htm
Advantages - easy install, less points of failure (no electrical, switches, etc) Disadvantages - not controlled by autopilot and if a yaw damper is used the servo may get more wear and tear.
2. Vic Syracuse style rudder trim build with a hinge attached to rear of rudder. http://www.myrv10.com/tips/mods/RudderTrim/index.html Advantages - Can be wired "through" yaw damper servo and "run" by the autopilot to auto trim the airplane so when the AP is disengaged and the yaw servo turns off the plane will not "lurch" as it will already be trimmed. Nice panel mounted switch. Disadvantages - More wire running to tail, another switch and indicator on the panel, potential re-balanceing of control surface.
