My first try at rigging a Pantograph .. It uses 2 ik chain armatures, rotation bones, and a few empties .. and is driven by the rotation of the wheels. Should also include a belt around the wheels etc .. Those 2 wire-frame cubes are the pole targets (empties). Yep you don't see many empties in the form of cubes and circles but I find it helpful to group empties that way according to function.
I'll upload a better version later with some explanation of how it's rigged if anyone expresses an
آی-ویدئو