How could it go straight up and down? As the robot moves around the room, the anchor for the vertical cable would no longer be directly above the robot.
I assumed the 5th cable would be directly connected to the robot, to lower and raise it straight up and down. So, cables from four corners of the room to the center point where the 5th cable is, and the robot hangs off that 5th cable and can raise/lower itself.
[–] philote 3 days ago