Hi
         I saw the post on LML about locking the controls and thought I would pass on what I have found and use.  I finally discovered that most normal systems for securing the rudder are difficult or impossible to employ.  I saw an adjustable aluminum bar used to safety lock a sliding patio door and put  RTV on the small end and padding on the other. The RTV end I place on the copilots right rudder and the padded end I place on the spar box.  I then use this to fully extend the copilots right rudder petal and so far  1 1/2 years since I have make the rudder lock it works well.  Then I restrain the stick with the copilot's seat belt.  It seems to be a cost effective and efficient solution to the problem.

Hope this helps

Jack Webb
L 360, L IV
ATP, CFI Airplanes & Instruments, Multi, & Sea
Many Type Ratings
Experienced Experimental Test Pilot both multi and single engine
Former Chief Engineering Test Pilot for a Major Manufacturer
AeroSpace Engineer BSAE
Ohio