This animation is NOT PHYSICALLY REALISTIC. Links are allowed to rotate through each other. The goal is simply to demonstrate multiple rotations, while sacrificing realism.
This animation demonstrates two rotations.
The first arm of the excavator rotates with an angular velocity of -0.5 radians per second.
The remote arm of the excavator rotates with an angular velocity of 0.8 radians per second.
The path of the tip of the crane is shown in pink.