Thanks for the tip about the control surface throws. I definitely need to increase the rudder throw. The rudder is quite small for this size of plane (I think). Reading about the real Catalina, they increased the height of the vertical stabilizer and the rudder on later productions models.
Some considerations on the rudder throw.
There is an angle of rudder rotation that is optimum.
It varies with the rudder shape and its airfoil.
Obviously the rudder is there to produce a side wise force.
To realize what I said above (optimum) if the rudder is rotated 90 degrees it would produce lots of drag and little side force.
The most efficient side force usually occur around the 40 to 50 degrees of rotation. If more force is needed it is quite obviously the use of a larger rudder area.
It is also an advantage to have some area in front of the hinge line which helps to reduce the forces on the rudder pedals. The servo in our model case.
There is a genral knowledge that a scale model is not considered by most pilot to be sensitive enough to the controls. Many pseudo scale models have enlarged tail surfaces compared to the proportions of the full size.
Some experts will explain that in terms of the Reynolds number.
Such explanations does not change the observed behavior or the desire by many to have more efficient control in the model.
Pilot of models generally like to tear the sky with constant maneuvers done rapidly. Full size planes do not fly that way.
I like the pics of the Catalina in prominence in its hanging location.
My favorite model is hanging in a similar way in my downstairs rec room.
Regards always de