Here is a drawing of the optimum
rudder linkage for an FSRV boat.
Rudder linkage and throw on an FSRV are absolutely critical for accurate, smooth turning. Normally people build the boat with a parallel linkage or worse. The problem then is that the user has to turn down the rates or EPA to reduce the rudder throw enough to drive the boat without zigzagging. There lies the problem. When you reduce the rates on the servo, the servo is actually only making a very small movement to make the turn and this exaggerates any slop in the linkage or slop in the servo itself but worse still, the force applied to the rudder is very much less than it should be.
Rudder linkage and throw on an FSRV are absolutely critical for accurate, smooth turning. Normally people build the boat with a parallel linkage or worse. The problem then is that the user has to turn down the rates or EPA to reduce the rudder throw enough to drive the boat without zigzagging. There lies the problem. When you reduce the rates on the servo, the servo is actually only making a very small movement to make the turn and this exaggerates any slop in the linkage or slop in the servo itself but worse still, the force applied to the rudder is very much less than it should be.
