A numerically controlled machine tool has at least one movement axis and is connected to a numerical controller which includes a parts program. Movements of each movement axis are limited by maximum permissible axis dynamics. The parts program has a sequence of instructions for machining a workpiece which specify different maximum desired speeds for the machining of the workpiece which change abruptly over time. The numerical controller approximates the different maximum desired speeds which change abruptly over time with a desired speed profile that is continuous over time and has a profile of the maximum desired speeds which is also continuous over time. The numerical controller uses the continuous desired speed profile to calculate the desired values of an actual movement profile of the movements for each movement axis.

A plasma cutting system for measuring or monitoring the voltage between a plasma torch and the material being cut to determine a voltage or voltage signature and comparing that measurement against predetermined values to indicate that an initial pierce of the material is complete, and based on the measurement, moving the torch or the material to a different location for additional cutting. The system further provides a Fix Drawing Tool, which will automatically detect and fix gaps or overlaps in a drawing that are very difficult to find visually. These gaps and overlaps become a problem when trying to make a proper toolpath because a CAM program requires a clean, closed shape. The system also provides a Dynamic Corner Looping system, which automatically adjusts with the feed-rate and accelerations of the toolpath and plasma machine, eliminates unwanted dross, sharpens corners and minimizes material loss. A pendant tethering system is also disclosed for managing control of a CNC machine remotely. Additional disclosed functionality includes a data collection system, a manual hand wheel with 3D simulation and a multiple fabrication head management system.

A plasma cutting system for measuring or monitoring the voltage between a plasma torch and the material being cut to determine a voltage or voltage signature and comparing that measurement against predetermined values to indicate that an initial pierce of the material is complete, and based on the measurement, moving the torch or the material to a different location for additional cutting. The system further provides a Fix Drawing Tool, which will automatically detect and fix gaps or overlaps in a drawing that are very difficult to find visually. These gaps and overlaps become a problem when trying to make a proper toolpath because a CAM program requires a clean, closed shape. The system also provides a Dynamic Corner Looping system, which automatically adjusts with the feed-rate and accelerations of the toolpath and plasma machine, eliminates unwanted dross, sharpens corners and minimizes material loss. A pendant tethering system is also disclosed for managing control of a CNC machine remotely. Additional disclosed functionality includes a data collection system, a manual hand wheel with 3D simulation and a multiple fabrication head management system.

A numerical control apparatus includes: a curvature radius calculating portion which calculates a first radius r.sub.a which is a radius of a passage arc C passing through three points of a start point P.sub.s, an object point P.sub.t, and an end point P.sub.e as a curvature radius R at the object point P.sub.t; a point sequence evaluating portion which calculates a chord error E to the passage arc C and compares the calculated chord error E and a previously defined permissible error; and a curvature radius correcting portion which calculates a second radius which is a radius of an arc in which a chord error with a front line segment and a rear line segment is the permissible error or less when the calculated chord error E exceeds the permissible error and corrects a curvature radius at the object point P.sub.t to the second radius.

A numerically controlled machine tool has at least one movement axis and is connected to a numerical controller which includes a parts program. Movements of each movement axis are limited by maximum permissible axis dynamics. The parts program has a sequence of instructions for machining a workpiece which specify different maximum desired speeds for the machining of the workpiece which change abruptly over time. The numerical controller approximates the different maximum desired speeds which change abruptly over time with a desired speed profile that is continuous over time and has a profile of the maximum desired speeds which is also continuous over time. The numerical controller uses the continuous desired speed profile to calculate the desired values of an actual movement profile of the movements for each movement axis.

A numerical control apparatus includes: a curvature radius calculating portion which calculates a first radius r.sub.a which is a radius of a passage arc C passing through three points of a start point P.sub.s, an object point P.sub.t, and an end point P.sub.e as a curvature radius R at the object point P.sub.t; a point sequence evaluating portion which calculates a chord error E to the passage arc C and compares the calculated chord error E and a previously defined permissible error; and a curvature radius correcting portion which calculates a second radius which is a radius of an arc in which a chord error with a front line segment and a rear line segment is the permissible error or less when the calculated chord error E exceeds the permissible error and corrects a curvature radius at the object point P.sub.t to the second radius.

A plasma cutting system for measuring or monitoring the voltage between a plasma torch and the material being cut to determine a voltage or voltage signature and comparing that measurement against predetermined values to indicate that an initial pierce of the material is complete, and based on the measurement, moving the torch or the material to a different location for additional cutting. The system further provides a Fix Drawing Tool, which will automatically detect and fix gaps or overlaps in a drawing that are very difficult to find visually. These gaps and overlaps become a problem when trying to make a proper toolpath because a CAM program requires a clean, closed shape. The system also provides a Dynamic Corner Looping system, which automatically adjusts with the feed-rate and accelerations of the toolpath and plasma machine, eliminates unwanted dross, sharpens corners and minimizes material loss. A pendant tethering system is also disclosed for managing control of a CNC machine remotely. Additional disclosed functionality includes a data collection system, a manual hand wheel with 3D simulation and a multiple fabrication head management system.

A numerical controller controls a relative speed between a tool and a workpiece on the basis of a machining program. In a case where a corner part exists between a current block and a next block of the machining program, the next block is prefetched, and an allowable speed at the corner part at an end point of the current block is calculated. At least one of pre-interpolation acceleration of an acceleration part, a pre-interpolation speed of a constant-speed part, and pre-interpolation acceleration of a deceleration part that are relative speeds between the tool and the workpiece is adjusted so that the relative speed between the tool and the workpiece is maintained at a preset allowable speed while the corner part is passed through.

A plasma cutting system for measuring or monitoring the voltage between a plasma torch and the material being cut to determine a voltage or voltage signature and comparing that measurement against predetermined values to indicate that an initial pierce of the material is complete, and based on the measurement, moving the torch or the material to a different location for additional cutting. The system further provides a Fix Drawing Tool, which will automatically detect and fix gaps or overlaps in a drawing that are very difficult to find visually. These gaps and overlaps become a problem when trying to make a proper toolpath because a CAM program requires a clean, closed shape. The system also provides a Dynamic Corner Looping system, which automatically adjusts with the feed-rate and accelerations of the toolpath and plasma machine, eliminates unwanted dross, sharpens corners and minimizes material loss. A pendant tethering system is also disclosed for managing control of a CNC machine remotely. Additional disclosed functionality includes a data collection system, a manual hand wheel with 3D simulation and a multiple fabrication head management system.

Systems, methods, and computer-readable media are provided for machining a feature on a work piece along a curving tool path including a spiral pattern with continuously varying radius. In particular, the feature is scribed by a tool while varying an angle of rotation of a cutting surface of the tool with respect to the work piece to maintain a substantially constant angle between the cutting surface and a corresponding relative translational movement between the cutting surface and the work piece along the spiral pattern. A dynamic feed rate of the tool also is varied continuously with respect to the work piece based on the continuously varying radius of the at least one spiral pattern to substantially maintain a target centripetal acceleration of the tool with respect to the work piece.