Abstract: A microprocessor numerical control for a milling machine including means for programming part features by the machine operator at the machine location. The control apparatus includes a CRT display which provides an inquiry system, and a keyboard for entry of data by the machine operator. The control system further includes a tape cassette deck operable to read or write data or program material into or out of the processor memory. The control system regulates motion in the X, Y and Z directions for the milling machine and also includes an external feed rate adjustment for either the XY plane or the Z axis direction which may be utilized by the machine operator to affect the programmed feed rates. There is further provided automatic tool length calibration and cutter diameter compensation for milling operations.

Abstract: A tool calibrator and method including a gauge head with a surface for chucking in a workpiece holder on a machine lathe. A plurality of contact surfaces on the gauge head function to contact the tool cutting edge when moved transverse to and parallel to the rotational axis of the workpiece holder. Electrical sensing circuitry detect resulting contacts and relay the same to the numerical control circuitry of the lathe for automatically determining relative position of the tool cutting edge. This input data is used to control movement of the tool in its tool holder after the gauge head has been removed and a workpiece mounted for the machining operation.