A Microprocessor-Controlled on-Machining Apparatus

An ion-milling apparatus used for surface-wave delay-line fabrication has been fitted with a work table which is positioned by a microprocessor operated computer. After the desired machining profile has been entered into the computer via a teletypewriter, the computer calculates the rate at which the work piece must be translated through the ion beam to obtain the desired profile and, by reference to an internal real time clock, issues pulses to a stepping motor at an appropriate rate. Operating parameters of the ion-milling apparatus which are critical to machining rate are monitored frequently by the computer as a basis for in-process alterations of the work piece translation rate to compensate for changes in system operating parameters. Upon completion of the run or upon the occurrence of any of several failure conditions, the computer shuts down the ion-milling apparatus and reports via the teletypewriter the reason for shutdown.