Abstract: A method of generating control code for a CNC machine is described. The method includes the steps of: (1) generating in a computer a first plurality of coordinate values, xi, yi, zi, said first plurality of coordinate values representing a plurality of first connected line segments which surround a vertical axis, said first connected line segments gradually descending to a first predetermined depth, (2) generating in a computer a second plurality of coordinate values xj, yj, zj, said second coordinate values representing a plurality of second connected line segments which surround the vertical axis, said plurality of second connected line segments having a starting point at approximately the first predetermined depth, and gradually descending to a second predetermined depth greater than the first depth, and (3) converting the first and the second coordinate values to a code for controlling the CNC machine.

Abstract: A tooling system comprises a plurality of elongate elements each having an upper surface, said elements being arranged in an array to present said upper surfaces for machining by cutting tool means; support means for supporting said elements, each said element being supported on said support means for axial movement between upper and lower positions relative to the other elements in the array thereby to enable adjustment of the vertical position of said element surface; and clamping means for clamping the array of elements in a closed position in which the elements contact one another for enabling the free ends of the elements to be machined to produce a desired surface contour.

Abstract: It is an object of the present invention to provide a controller for a machine tool and a five axis simultaneous control machine tool controlled thereby which can improve the machining accuracy in machining by controlling a driving axis including a linear axis and a pivoting axis. The controller comprises a detecting member 102 detecting a machining position where a pivoting axis is reversed in machining by the machine tool 1 based on the control data, an allowable position error setting member 103 setting an allowable position error ? between a commanded machining position P1 and an actual machining position P2, an allowable acceleration deciding member 107 deciding the allowable acceleration about the pivoting axis based on a distance L1, L2 from the machining position of the reversed axis to a center of the pivoting axis and based on the allowable position error ? being set, and a controlling member 108 controlling a velocity about the driving axis based on the allowable acceleration.

Abstract: A machine for cutting hides and the like and sheet-like material in general, with simplified-access worktable, comprising a footing for supporting a worktable, and cutting elements adapted to be moved on said worktable along the contours of the shapes to be cut, by way of numeric control, wherein the imaginary extensions of three sides of said worktable do not encounter obstacles due to said cutting elements and supports thereof, the fourth side of the worktable being surmounted by a cantilever arm that supports said cutting elements.

Abstract: A method for setting a working origin for a rotary tool in contact with a work piece to be machined, having: applying to a main spindle which holds the rotary tool, with a tip of a cutting edge of the rotary tool in contact with an outer surface of the work piece fixed to a work table, a load torque to such an extent that the rotary tool is not caused to be rotated; applying the load torque to the main spindle, and moving either the work table or the main spindle in a jog feed in a direction of any one of feed shafts such that the tip of the cutting edge is moved away from the outer surface along an axial direction of the rotary tool or in the direction orthogonal to the axial direction; and setting a coordinate at the moment when the main spindle starts rotation as a working origin of the jog feed in the direction of the any one of the feed shafts.

Abstract: A mill bed for use in association with a mill includes a base frame, an outer frame and an inner frame. The outer frame is moveably attached to the base frame whereby it is at least partially rotatable around an outer axis. The inner frame is rotatably attached to the outer frame and at least partially rotatable around an inner axis. A control system is operably attached to the outer frame and the inner frame to control movement of the outer and inner frames.

Abstract: The invention is a method of creating greater accuracies for wear compensation of a finishing tool during the finishing of workpieces, in which a reference surface is ablated by initially traversing the finishing tool over the reference surface and determining the actual wear of the finishing tool as a result of this initial feed motion of the finishing tool controlled by an NC feed program of an NC machine. The actual measured wear of the finishing tool as a result of the initial traversing feed motion over the reference surface is compared to a known empirical wear trend line for the workpiece and the feed motion of the NC feed program for the next workpiece is recalculated as a function of the comparative actual wear of the finish tool with respect to the known empirical wear trend line.

Abstract: The present invention relates generally to deformation machining systems and methods that combine, in a single machine tool setup, the machining of thin structures and single point incremental forming (SPIF), such that novel part geometries and enhanced material properties may be obtained that are not achievable using conventional machining or forming systems and methods, individually or collectively. Important to many applications, lighter weight parts may be produced at lower cost using a conventional 3-axis computer numerically controlled (CNC) machine tool or the like, instead of the conventional 5-axis CNC machine tool or the like that is typically required.

Abstract: A raster cutting apparatus and method for producing accurately formed, aspheric ophthalmic lenses having a good quality surface finish. The accurate form and good surface finish are obtained by using a substantially spherically shaped cutting tool having a large radius. The methods include utilizing a cutting path which provides substantially constant cutting-force, such as a constant surface-cutting-speed raster pattern.

Abstract: The invention relates to an apparatus for machining bevel gears in an indexing method and method for machining the pitch of gears, wherein the production-related pitch error is compensated. The apparatus (20) comprises an interface (11, 12) and can be connected to a measurement system (10) by means of this interface (11, 12). The interface is designed such that the apparatus (20) can take correction values or correction factors from the measurement system (10) in a form in order to be able to adapt master data or neutral data. The data, which was originally present in a memory (51) of the apparatus (20), is corrected on the basis of these correction values or correction factors before production of one or more bevel gears (31) is initiated on the apparatus (20).

Abstract: An apparatus for force monitoring and control of a multi-axis router. The spindle assembly has a mounting plate that is attached to a base plate in the router assembly through three equally spaced load cells. The load cells are maintained in tension because the spindle assembly is suspended below the base plate. The center of gravity of the spindle assembly is in the center of the three load cells. Forces on the cutting tool are measured by the load cells, which are monitored by a controller that determines the load on the cutting tool. The feed rate of the cutting tool is adjusted based on the calculated cutting tool force. Abnormal conditions, such as an unbalanced or dull tool, are determined from the measured forces.

Abstract: In a method for positioning machine axes in machine tools, a numerical control converts setpoint positions of a tool, predefined in workpiece coordinates, into setpoint positions of machine axes based on a kinematic chain defined by a kinematic table. In this context, transformations of the coordinates are indicated in the kinematic table in a plurality of entries describing the kinematics of the machine tool, by specifying an axial direction and an associated transformation amount, respectively, per entry. For a machine axis having an error in a direction other than the respective axial direction, error transformation amounts dependent on the axial position are entered into the kinematic table.

Abstract: A numerically controlled machine tool performs machining by rotating a rotational tool attached to a tool holder mounted on a spindle, with keys fitted into key grooves in the tool holder. The numerically controlled machine tool includes predetermined-amount rotating unit for stopping the tool holder at a predetermined rotational position and then rotating the tool holder by a given amount, and a distance sensor which is installed apart from the tool holder and measures a distance to the outer surface of the tool holder. The predetermined-amount rotating unit stops the tool holder at a rotational position at which the key grooves do not face the distance sensor, then rotates the tool holder by the given amount. The distance sensor measures the distance to the tool holder while the tool holder is rotating. The measurement result is compared with a reference distance or distances to discriminate between normal and abnormal rotational run-out of the tool holder.

Abstract: A numerical control unit issues a sequence of instructions for causing a spindle of a cutter disk in a tool machine to perform successive straight displacements approximating a spiral of Archimedes, with a predetermined angle step from one point to the next, and issues one or more ADIS instructions for merging each of the straight displacements with the next. The spiral path is such that the cutter disk will progressively shave a chip of a predetermined thickness over several revolutions, until its cutting edge is near the intended groove bottom. The tool is then caused to follow a merging path leading to a final point lying on the intended groove bottom, and finally is caused to follow a full circular path coaxial to the bore starting from the final point.

Abstract: An end mill 10 is a tool for milling a metal block such as a metal mold and is placed in a machine tool such as a milling machine when in use. The end mill 10 is used to provide a rotary milling cutter and a milling method using the same, in which it is possible to perform orthogonal milling and pocket milling to efficiently form four corners with small radius, without repeatedly milling using a small-diameter end mill. The end mill 10 has two cutting edges 11a and 11b at its distal portion, and an edge angle D1 formed by the two cutting edges 11a and 11b is 70.53 degrees.

Abstract: Relative movements of a tool and a workpiece are controlled by moving a tool axis in all spatial dimensions for the material-removal machining of the workpiece to produce a desired target contour of the workpiece by a sequence of relative movements along a tool trajectory of the tool. The tool trajectory is subdivided into a multiplicity of target segments along which the tool is in engagement with the workpiece so that the orientation of the tool axis is consistent within a target segment, while the orientation of the tool axis is variable over the entire tool trajectory, and a respective and point of a target segment is connected by a linking pivot movement, during which the tool does not engage the workpiece and in which the orientation of the tool axis is altered, with a starting point of a further target segment.

Abstract: A milling method is for producing milled structural components of materials that are difficult to machine by chip-cutting. A milling tool with a tool radius is rotationally driven about an axis of the milling tool to ensure a central rotation thereof, whereby a reference point of the milling tool preferably lying on the axis is moved on several curved paths, whereby the paths preferably comprise different curvatures, and whereby the milling tool is moved on the paths with a radial miller feed relative to the material. The curvature at each path point of each path is determined in such a manner that an optimized or maximized circumferential contact of the milling tool is ensured for each path point.

Abstract: (A) V-CAD data of an object (1) is prepared. (B) A processed surface shape after NC processing is predicted by simulation using the V-CAD data. (C) The object is subjected to NC processing by a predetermined NC program, and a processed surface shape after NC processing is measured, and (D) processing correction data is obtained from a difference between the processed surface shapes acquired by simulation and measurement, and the NC program is corrected based on the processing correction data. As a result, the ultra-precise processing is enabled even if a workpiece or a tool has low rigidity and an inconstant quantity of deformation.

Abstract: End-mill machining control method and apparatus in which cutting forces tangential and normal to tool motion are detected and machining is controlled based on the detected cutting force values. A primary component Ft and motion axis components Fx, Fy of a cutting force are determined from current values of a spindle motor and motion axis motors for tool feed. A cutting-engaged angle ?en is determined from a radius R of a tool and a depth of cut I into a workpiece. A motion direction angle ? is determined from distribution motion amounts ?X, ?Y to the axes. The cutting forces Fm, Fs tangential and normal to tool motion are determined from the primary component Ft and a motion axis component Fx or Fy whichever is the largest, the cutting-engaged angle ?en, the motion direction angle ?. The accuracy of the determined cutting forces Fm, Fs is high since they are determined from the primary component Ft less affected by disturbance and the largest axis component of the cutting force.

Abstract: A method for the orientation of a spindle of a numerically controlled and rapidly rotating spindle by which the spindle is brought from an initial rotational speed into a predetermined position of rest. The method includes performing a first phase of orientation of the spindle by braking the spindle to a threshold rotational speed, wherein during the braking a switching over to a position controller is prepared, the switching over is performed at a switching time during a transition from the first phase of orientation to a second phase of orientation, the switching over is continuous in regard to position and/or rotational speed, and wherein a rotational speed of the spindle drops strictly monotonically.

Abstract: A machine having X- and Y-axis linear moving axes and a pivot axis B for rotationally pivoting a pivot member having a tool arranged at a distal end thereof about an axis parallel to a Z axis is controlled. A moving command obtained by a command program commanded by a position expressed by X, Y, and Z in a three-dimensional orthogonal coordinate system is subjected to an interpolation process to calculate amounts of interpolation movement (?X, ?Y, and ?Z) of the respective orthogonal axes. An amount of rotation ?? of the pivot axis required for moving the tool by the amount of movement ?Y in the Y-axis direction is calculated. An amount of correction movement ?x for canceling the movement in the X-axis direction caused by the rotation ?? of the pivot axis B is calculated. Values (?X+?x), ??, and ?Z are outputted to the X axis, the pivot axis B, and the Z axis, respectively.

Abstract: A machining feed rate for machining a workpiece portion to be machined by a machining tool based upon a machining program is set by reading a data of the workpiece portion, by sectionalizing the workpiece portion in an area corresponding to a workpiece shape of the workpiece portion, and by determining a shape change point based upon a workpiece shape of the workpiece portion. The machining feed rate is set for each area and for each shape change point with reference to a predetermined parameter corresponding to an attribute of the each sectionalized area and corresponding to an attribute of the each determined shape change point.

Abstract: Upon analyzing a processing program (5) in an analyzer (11, 31), a numerical control apparatus extracts information about a contact position between a tool and a workpiece, and based on the information, it calculates a main spindle revolution instruction value in a main spindle revolution calculator 14, 38). In a CAM system, information about the contact position between the tool and the workpiece to be supplied to the numerical control apparatus is calculated and added to the processing program.

Abstract: An NC apparatus 1 replaces a required machining shape of a workpiece 5 with a predetermined canned machining cycle depending on a specification of machining conditions including a machining start point, a machining end point, and the size of an end mill E to be used. Calculation of an estimated value of cutting force exerted on the end mill E fed along the assumed tool path during the replaced canned machining cycle is repeated until a predetermined comparison and evaluation result is obtained in comparison with a predetermined appropriate value. Accordingly, the tool path of the end mill E together with the feed rate in each portion of the tool path is determined. This permits generation of an NC program which is used in a NC machine equipped with an end mill serve as a cutting tool, and which optimizes the tool path of the end mill together with the feed rate in each portion of the tool path such as to achieve high machining efficiency and accuracy.

Abstract: A machine tool 10 to fashion objects from blocks of material having a material-remover 16 able to move in at least two degrees of freedom and having the material 18 controlled by processing circuitry. The processing circuitry 18 determines a path along which the material-remover 16 should move, allowing the depth of a cut made by the material remover to vary. The movement of the material-remover 16 is so controlled to improve bulk material removal when compared to prior art machines.

Abstract: Fiducial calibration systems and methods for precisely and accurately manufacturing a part from a workpiece, inspecting or measuring a part, and/or assembling a plurality of manufactured parts including providing a workpiece, wherein the workpiece and the associated processes are subject to environmental and structural variations, and disposing a plurality of datums on a surface of or within the workpiece. The systems and methods also including calibrating the separation distance between each of the plurality of datums to workpiece distance units and disposing the workpiece in a machine, wherein the machine is subject to environmental and structural variations.

Abstract: A rotational machining and quality assurance method for thermally extruded linings of turbomachinery are provided. First, a harder top coating is removed by turning, then the lining is finish-turned to size. During the finish-turning, defined turning parameters are maintained and a cutting force characteristic is quantitatively detected and stored. The force characteristic is compared with predetermined limit values, and, depending on the result of the comparison, the lining is approved for use or is produced again.

Abstract: A correction apparatus 1 comprises a correction amount setting section 3 and a correction execution section 4 and provides in an NC lathe 100 equipped with a first tool rest 106 and a second tool rest 108 which are movable in the X-axis direction and in the Z-axis direction. The correction amount setting section 3 sets correction amounts for canceling the displacement of the second tool rest 108 in the X-axis direction caused depending on the position of the first tool rest 106 in the Z-axis direction and for canceling the displacement of the first tool rest 106 in the X-axis direction caused depending on the position of the second tool rest 108 in the Z-axis direction. The correction execution section 4 corrects movement target position data regarding the first tool rest 106 and the second tool rest 108 in the X-axis direction on the basis of the correction amounts.

Abstract: In a method for machining a workpiece, and for identifying a sequence of steps for machining a workpiece, a final shape required for the whole or part of the workpiece (is identified at 34), a three dimensional envelope shape is generated around the required shape (36), differences between the current shape and the envelope shape are generated at (38) to allow a sequence of cuts to be generated at (40) and a tool path at (42) from which the current stock part can be cut down to the envelope shape. The definition of the current stock is then updated at (44) and the sequence repeated until the workpiece has been machined to the required shape.

Abstract: In a complex machining machine tool, a tool rest capable of attachably and detachably installing tool installing inserts thereon is provided, a plural number of virtual tools is set and registered concerning a predetermined at least one tool together with its indexing positional data in tool file, the tool data of the corresponding virtual tool is read out from the tool file on the basis of the machining instruction by the virtual tool stored in machining program, and the corresponding virtual tool is indexed on the tool rest on the basis of the indexing positional data, and then machining with the virtual tool is executed. At the time of machining, it is possible to continue machining with the same tool by only positional indexing without changing the tool. The work for changing tools can be extremely decreased even if machining contents are changed or it is necessary to change tools by tool exhaustion.

Abstract: A numerical controller capable of precisely controlling a machine tool having an axis for turning a table with a simple machining program and easily coping with variation of a tool length. A machining path is commanded in a workpiece coordinate system turning with a table. The commanded machining path for linear-motion axes is interpolated based on a commanded machining velocity, to obtain interpolated positions on the machining path. Also, the commanded motions for rotational-motion axes are interpolated to obtain interpolated positions for the rotational-motion axes. The interpolated position for the linear-motion axes is corrected based on the interpolated position of the rotational-motion axes. The servomotors for the linear-motion axes are driven based on the corrected interpolated positions and the servomotors for the rotational-motion axes are driven based on the interpolated positions of the rotational-motion axes.

Abstract: A furniture surface includes a new solid wood substrate, a two-color silk screened image on the substrate, and a CNC-carved and embossed indentation in the substrate that provides a relief effect located in reference to the printed image so as to make a composite ornamentation on the substrate that makes the substrate look antique.

Abstract: In a complex machining machine tool, a tool rest capable of attachably and detachably installing tool installing inserts thereon is provided, a plural number of virtual tools is set and registered concerning a predetermined at least one tool together with its indexing positional data in tool file, the tool data of the corresponding virtual tool is read out from the tool file on the basis of the machining instruction by the virtual tool stored in machining program, and the corresponding virtual tool is indexed on the tool rest on the basis of the indexing positional data, and then machining with the virtual tool is executed. At the time of machining, it is possible to continue machining with the same tool by only positional indexing without changing the tool. The work for changing tools can be extremely decreased even if machining contents are changed or it is necessary to change tools by tool exhaustion.

Abstract: A lapping surface patterning system includes a patterning apparatus which can be removably mounted over the lapping surface of a continuous polishing tool. The patterning apparatus includes a radial arm having a movable cutting tool carriage mounted thereon. The cutting tool carriage positions a cutting tool at a desired radius from the center of the lapping surface. The patterning apparatus further includes an outer support having a carriage which positions an outer end of the radial arm, thereby positioning the cutting tool at a desired angular position. A motion control system transmits control signals to the two carriages, thereby driving the cutting tool over a desired pattern. This system can be used to repeatedly and consistently form a pattern of grooves in the lapping surface of the polishing tool.

Abstract: A milling method is provided in which a finished part of any desired contour is milled from a blank of any desired contour by the milling tool being guided on a continuous, spiral guide path from the blank continuously to the finished part. In this case, material is continuously removed during the milling operation without ever lifting the tool or clamping the workpiece in place again. This results in a reduced machining time of the workpiece. The continuous, spiral guide path permits a harmonic change of form from the blank to the finished part with smooth guidance of the tool. The method can also be carried out with ceramic tools.

Abstract: An automated quill drive assembly is adapted to be retrofit on a milling machine having a frame presenting a quill head and a quill supported on the head for rotation and for relative shiftable movement along a linear axis between retracted and extended positions. The quill head includes a centrally disposed lower lug, a quill feed engagement control lever boss located above and spaced to one side of the lug, and a transmission cover opening located above and spaced to a side of the lug opposite the quill feed engagement control lever boss. The automated quill drive assembly includes a housing adapted to be mounted to the lug, the quill feed engagement control lever boss, and the transmission cover opening, a motor supported on the housing, and a transmission supported on the housing for transmitting automated movement from the motor to the quill to move the quill between the retracted and extended positions.

Abstract: The invention relates to a method for processing a work piece by removing material with a tool in which the tool is guided over the work piece in paths. The pivoting and cambering angle of the tool is selected in every point such that the width of a tolerance zone is optimized. Within said zone, the effective zone (K) of the tool is located in a tolerance zone of the desired specified surface (Psi) of the work piece. The distance between two points (Pl, Pr) is maximized, said points characterizing the furthest outlying points of the tolerance zone. As a result, it possible to produce surfaces having a high precision with a small number of paths.

Abstract: A system and method for inscribing an item is provided. The system includes a housing having a door, an inscriber, and a support. The inscriber is disposed in the housing and is operable to inscribe the surface of an item secured in an item carrier. The support has a positioning structure that is configured to engage the item carrier and establish a reference point so that the location of the surface of the item with respect to the support is determinable. The support moves between a loading position and an inscribing position to position the item for inscribing. There is also provided a controller that governs the movements of the inscriber and includes an input device. The input device is moveable between a first position to receive characteristics about the item to be inscribed and a second position to receive a message to be inscribed on the surface of the item.

Abstract: An adaptive control system for adaptively controlling a turning operation performed at a work piece by a turning tool adjusts a controlled input operation parameter F to maintain an output operation parameter &Dgr;M substantially at a predetermined value &Dgr;Mo to compensate variation of the output operation paramemeter &Dgr;M caused by the variation of at least one operation condition B=B (t). The system comprises a sensor (8) of the output operation parameter &Dgr;M for providing a signal Uc proportional to a current value &Dgr;Mc and an adaptive controller (10) for determining a value Fc to which the input operation parameter F should be adjusted, as a function of kUc, where k is a signal transmission coefficient which comprises an invariant signal transmission coefficient component ko inversely proportional to &Dgr;Mo.

Abstract: A computer-implemented method and system is disclosed for controlling a cutting tool of a high speed cutting machine. The method and system provides an effective tool path for controlling a cutting machine under a constant rate of material removal in a high speed cutting machine in order to get away with the extreme cutting forces. The tool path also allows to better transfer the heat generated between the cutting tool and the workpiece through the chip. The method and system can be applied to any geometry of final shape of a workpiece.

Abstract: A number of computer-numerical-control (CNC) machine controllers are associated in the same plant or facility or in related facilities. Each CNC machine controller gathers and stores status information related to the state of operations being performed. A remotely located central computer separately addresses each of the controllers to transfer the status information to a central location where the entire plant or facility operation can be evaluated.

Abstract: A machine tool 10 to fashion objects from blocks of material having a material-remover 16 able to move in at least two degrees of freedom and having the material 18 controlled by processing circuitry. The processing circuitry 18 determines a path along which the material-remover 16 should move, allowing the depth of a cut made by the material remover to vary. The movement of the material-remover 16 is so controlled to improve bulk material removal when compared to prior art machines.

Abstract: A method adapted to achieve a high rate of material removal when, for example, milling a cavity into a work piece. The method includes providing for a cutter path in which the angular engagement between the cutter and the work piece is maintained below a predetermined value to prevent premature wear of the tool, providing for a cutter path which permits a constant cutter feed rate including during directional changes in the path, and machining a series of nested pockets into the work piece utilizing cutter paths as provided for above.

Abstract: An NC controller determines a subsequent point sequence position in each sampling by interpolation calculation with a section between a corner cutting starting point and a corner cutting end point as a machined section. The NC controller then internally calculates a spindle rotating angle in a coordinate position where an outer end of a cutting edge is positioned at the subsequent point sequence position. Based on the spindle rotating angle and the substantial diameter of the rotary tool, the NC controller internally calculates coordinate values of the spindle at the subsequent point sequence position. Based on the coordinate values of the spindle, the rotary tool and a workpiece are relatively shifted on a plane parallel to the bottom surface of the tool while the spindle rotation is controlled in synchronization with the shifting, thereby cutting the corner.

Abstract: An automated quill drive assembly is adapted to be retrofit on a milling machine having a frame presenting a quill head and a quill supported on the head for rotation and for relative shiftable movement along a linear axis between retracted and extended positions. The quill head includes a centrally disposed lower lug, a quill feed engagement control lever boss located above and spaced to one side of the lug, and a transmission cover opening located above and spaced to a side of the lug opposite the quill feed engagement control lever boss. The automated quill drive assembly includes a housing adapted to be mounted to the lug, the quill feed engagement control lever boss, and the transmission cover opening, a motor supported on the housing, and a transmission supported on the housing for transmitting automated movement from the motor to the quill to move the quill between the retracted and extended positions.

Abstract: An automated quill drive assembly is adapted to be retrofit on a milling machine having a frame presenting a quill head and a quill supported on the head for rotation and for relative shiftable movement along a linear axis between retracted and extended positions. The quill head includes a centrally disposed lower lug, a quill feed engagement control lever boss located above and spaced to one side of the lug, and a transmission cover opening located above and spaced to a side of the lug opposite the quill feed engagement control lever boss. The automated quill drive assembly includes a housing adapted to be mounted to the lug, the quill feed engagement control lever boss, and the transmission cover opening, a motor supported on the housing, and a transmission supported on the housing for transmitting automated movement from the motor to the quill to move the quill between the retracted and extended positions.

Abstract: A history of function values of a spindle rotation frequency in each time period from present to past is stored in a data table 22D and corrective coefficients are stored in advance in a corrective coefficient table 22C relating the coefficients to the location in the data table 22D. Each location and corrective coefficient are read out from the corrective coefficient table 22C and the function value of the spindle rotation frequency corresponding to the location is read out from the data table 22D. The compensation value is calculated from the total sum of each product of the function value and the corrective coefficient in each location and compensate the NC command position with the compensation value.

Abstract: A tool, attachable to a spindle of a machine tool and capable of changing independently a rotational speed of a cutting tool from that of the spindle, provided with a cutting tool for machining a workpiece, an electric motor for driving the machining tool, a generator for generating electric power to drive the electric motor by the rotation of the spindle, a tool holding part for rotatably holding the cutting tool, a casing for holding the electric motor, the generator, the tool attachment part, and the tool holding part, and a locking part for preventing rotation of the casing by engagement with a non-rotating part of the machine tool.

Abstract: A method of guiding a tool for machining a work piece of a material block, the material-removing work portion of the tool being guided to move along a first guide path while a further point on the axis of the tool, which is located at a distance from the work portion, is guided along a prescribed second guide path, whereby the five kinematic coordinates of the movement of the tool are fully determined.

Abstract: A milling cutter is moved relative to a workpiece rotating about a given axis to thereby cut the workpiece into a last. A milling cutter moving apparatus moves the milling cutter in accordance with movement data stored in a memory. The movement data is such that when the milling cutter is moved relative to the rotating workpiece in accordance with the movement data, the cutting edge of the milling cutter, at each of the rotational positions of the workpiece, is at a location where it would contact the surface of the last if the last were rotated about the given axis.