Machine bed support key to accuracy

A machine tool bed serves several important functions. It supports the machine's moving elements and supports them in geometric relations to each other. It is typically desirable for the bed to be as flat as possible, which requires considerable effort to scrape or grind the surfaces on which the guide ways are mounted. The bed should be stiff, thermally stable and able to absorb or dissipate vibration. If the machine bed is very stiff, then three connection points between the bed and the foundation are sufficient to support the bed. As a machine gets larger, it becomes unfeasible to support the machine on three points, and more feet are required. With larger machines, the bed derives some of its stiffness from the foundation, which is typically comprised of thick slabs of reinforced concrete.