Electroimpact has developed a second generation of mobile robots with several improvements over the first generation. The frame has been revised from a welded steel tube to a welded steel plate structure, making the dynamic response of the structure stiffer and reducing load deflections while maintaining the same weight. The deflections of the frame have been optimized to simplify position compensation. The caster mechanism is very compact, offers greater mounting flexibility, and improved maneuverability. The mechanism uses a pneumatic airbag for both lifting and suspension. The robot sled has been improved to offer greater rigidity for the same weight, and dual secondary feedback scales on the vertical axis further improve the rigidity of the overall system. Maintenance access has been improved by rerouting the cable and hose trays, and lowering the electrical cabinet. The mobile robot is sized so it can be shipped complete on a lowboy trailer for deliveries that can be completed by truck. It can also be broken down for container shipping, and reassembly at the customers' site is a straightforward process. The mobile robot can now be placed in position over obstructions by raising the robot on its vertical axis prior to moving it into the final assembly position.