Abstract: An adapter plate attached to the top of the riser, with a surface area extending outward from the top of the riser to provide the surface area larger than a perimeter of the top of the riser; a first guide mounted off-center of the adapter plate on a first side of the adapter plate; a first index paddle movably mounted on the first guide, comprising an extending portion that extends off-center of the first index paddle and configured for receiving a first robotic arm; and a first actuator for moving the first index paddle with respect to the adapter plate between an inward position and an outward position, wherein the extending portion in the outward position projects farther from the riser than in the inward position to extend a reach of the first robotic arm.