This blocks is quite genious, it uses geometric and dimentional constraints, distance multiplier on stretch action and so on.
Use BEDIT command to see by yourself how each parts are created.
I attached a small video I have done a few mounths ago which just show that a poor single geometrical constraint (coincident) can do useful things, it's up to you to discover all the possibilites with the others, like that beautiful crane. 🙂
