One of the things to pay attention to when building any RC vehicle is the setup of the servo’s. In (almost) all cases, the servo is connected to the controlled handle using linkages. One of the rules-of-thumb is that the servo, connecting rod and slave handle need to be at right (orthogonal) angles. Obviously I wanted to know WHY. John Vugts explains this in more detail, but I still wasn’t satisfied.
Note that the angles are measured in the mathematical way: counterclockwise starting from the horizontal X-axis.