Patent ID: 7090561

Claim:
A method for calibrating a CNC apparatus for controlling a machine tool, the CNC apparatus having a memory configured to compensate for offsets in a pivot point; the machine tool having a head, a pivot point, a spindle, a table, and at least four axes including an X-axis, a Y-axis, a Z-axis, and a C-axis, said method comprising: placing an artifact of known height on the table; placing a plug having a known diameter on the spindle; touching the plug to the artifact in a plurality of orientations of the plug and in a plurality of locations of the plug and the artifact to determine uncalibrated X and Y pivot point locations at a plurality of orientations of the spindle; and utilizing the uncalibrated X and Y pivot point locations to determine and store values in the memory of the CNC apparatus to compensate for offsets in the pivot point.