Abstract: Actual machining positions P1, P2, . . . corresponding to command positions S1, S2, S3 . . . of each block of NC data are obtained by trial machining. Positions that correspond symmetrically to the actual machining positions P1, P2, . . . with respect to the command positions S1, S2, S3 . . . of each block are obtained. Modified NC data are created with use of the symmetrical positions as modified command positions for each block. The modified NC data include correction values for modifying positional differences attributable to a delay in a servo system. Therefore, if machining is carried out in accordance with the modified NC data, the correction values and a follow-up delay attributable to the actual delay in the servo system cancel one another, so that a high-accuracy work shape can be obtained.

Abstract: A machine tool includes a tool magazine for accommodating a plurality of tools, the tool magazine including a tool ejecting section, feeding means for selectively feeding one of the tools accommodated in the tool magazine to the tool ejecting section of the tool magazine, and feed control means for controlling the feeding means so that a feeding speed of the feeding means is set on the basis of a type of a machining operation executed during feed of the tool.

Abstract: A hand-held, portable device recommends dynamically preferred speeds for stabilizing or reducing undesirable vibration such as chatter in a machining process. The device may be applied to machining processes such as turning, boring, milling and drilling which exhibit a relative rotational motion between the cutting tool and workpiece. The device measures in a safe, non-contact manner via a microphone the dominant audio signal component of the sound pressure emanating from the machining processes. Without prior knowledge of the machining process parameters or the dynamic characteristics of the machine tool or workpiece, the audio signal is conditioned and processed to determine the frequency component levels. The rotational speeds which are more likely to lead to a stable machining process are calculated based on the number of teeth on the cutting tool and the identified dominant frequency of vibration. The dynamically preferred speeds are displayed as recommendations to the process operator or machinist.

Abstract: To determine whether a machine tool is operating effectively, the present invention system, instead of directly measuring the operating parameters of the machine tool, monitors the presence or absence of any holes made by the machine tool and the quality of those holes, if made. The operational effectiveness of the machine tool is then correlated with the data thus monitored.