Many machines for the processing of sheet-metal into desired components are fairly large systems, particularly those that process standard metal sheets that may be several feet in both width and length. It is generally considered important that the machine maintain a known position of the sheet metal with respect to a processing head, such as a cutting head, during processing.
In many such machines, the sheet metal workpiece is placed upon a support that remains stationary as a cutting head traverses the workpiece across a workpiece processing area. These machines generally employ a heavy and stiff frame that supports both the workpiece and processing head and the necessary motion systems that provide the relative motion. Such frames can weigh in excess of several thousand pounds, for example.
Particularly in processing machines that employ a high power beam, such as a laser beam, to process the workpieces, it can occur that the beam at times passes undeflected beyond the workpiece and can potentially damage machine components on the opposite side of the workpiece processing area.