I tried to study the motion of a crab raising its claw. And it might be a paradoy, but I still find it interesting working with motiongen.
From Legs to Arms (They are basically using the same set of mechanism, the only difference is the length and the position of the piece.)
Then I raise the question that since now the only way to move the whole linkage mechanism is to use the thin wood stick at the bottom, is there an easy way to make it rotate?
One possible solution that come into my mind is that I can attach thin strings to the wood stick and then pull it, resulting in a rotation motion.
Head Turning Motion