Abstract: A controller uses detection information of a contact sensor or time-series data of a detection value related to a drive motor included in a rotation mechanism and/or a feed mechanism to acquire a coordinate value when a cutting tool comes into contact with a to-be-cut object or a component. The controller determines a relative positional relationship between the cutting tool and a rotation center of the to-be-cut object based on coordinate values when the cutting tool comes into contact with the to-be-cut object subjected to turning work or a reference surface whose relative positional relationship with the rotation center of the to-be-cut object is known at least at two positions different from a rotation angle position of the cutting tool during the turning work.

Abstract: The invention relates to a dynamically dampened centerless grinding machine tool comprising wheels between which there is arranged a part to be ground, heads for carrying the wheels, at least one translation means for translating one of the heads to cause a movement according to a separation and approach direction of the wheels, detection means for detecting a vibration of at least one of the heads, and at least one damper configured for causing a vibration damping movement.

Abstract: A controller of a machine tool includes a plurality of feed axes that feed a tool, machines a workpiece while making the tool oscillate and includes: an oscillation command creation unit which creates an oscillation command based on a machining condition; and a control unit which machines, based on the oscillation command and a movement command, the workpiece while making the tool oscillate, and the oscillation command creation unit creates, when the machining condition indicates machining by an interpolation operation of one feed axis of the plurality of feed axes, the oscillation command so as to make the tool oscillate in a direction along a machining path and changes, when the machining condition indicates machining by a simultaneous interpolation operation of the plurality of feed axes, the oscillation command so as to change the direction of the oscillation with respect to the machining path.

Abstract: A system is placed upon a target object and a machining tool. The system comprises a variety of sensors to detect adverse relative movement and position loss of the target object as it is affected by the machining tool. The system further comprises portable sensors in communication with a printed control board, configured to communicate position data to a remote computing device. The remote computing device may receive the position data, process it, and present output to a display. The system may detect position, kinematic, and mechanical issues present during the machining process by comparing the position data to thresholds, including position loss, and automatically adjust the operation of the machining tool in response.

Abstract: A vibration cutting process diagnostic device diagnoses the propriety of a vibration cutting process to machine the sectional shape of a working object into a non-complete round shape by reciprocating a movable shaft. This device includes a frequency analyzer to calculate a frequency component contained in a position command signal for the movable shaft on the basis of shape data, which is machining shape data on a workpiece treated as the working object, and a machining speed set value; and a process diagnosis executor to diagnose the propriety of machining the shape data under the machining speed set value on the basis of the frequency component and a movable shaft parameter of the movable shaft.

Abstract: An automatic carving device for a wheel, including a rack, a chassis, a lifting cylinder, brackets, bearing blocks, linear bearings, mounting plates, guide shafts, a lifting shaft, a servo motor, a synchronous pulley, a connection plate, a synchronous belt, a synchronous pulley, a pedestal, a connection shaft, a servo motor, a shaft sleeve, a lower end cover, a connection shaft, a shaft sleeve, and an oil cylinder. The automatic carving device for the wheel can automatically carve characters on the wheel, meanwhile it also has the characteristics of simple structure, convenience for manufacturing, stable performance and high precision that can meet the machining requirement, and can also meet the requirement of automatic production.

Abstract: A machine implement includes sensors that measure a force imparted by the machine implement to a structure during a machining process. A sensor array coupled to the structure measures the vibrational response of the structure to the imparted force. Analysis software compares the imparted force to the vibrational response to generate a transfer function for the structure. Based on the transfer function, a tool-path of the machine implement may be adjusted such that the resulting structure has precise vibrational characteristics that substantially comply with a set of design goals for the structure.

Abstract: A guide bush control device includes a guide bush motor that rotates and drives a guide bush; and a controller that controls driving of the guide bush motor, the guide bush control device controlling rotation of the guide bush by controlling the driving of the guide bush motor with the controller, wherein the controller includes a fixing unit that fixes the guide bush non-rotatably by exciting the guide bush motor in a rotation stop state.

Abstract: The invention provides an implementing method of cloud numerical control system. The method implements a numerical control system with functions of online error compensation, CAD/CAPP/CAM/CNC integrating and interactively cooperative assembling machining control. The cloud numerical control system includes a small cloud numerical control system a large cloud numerical control system. The small cloud numerical control system focuses on inside control of a single numerical control machining device and includes a cloud control core node, cloud measure and control subnodes and fine-tuning driving units. The large cloud numerical control system is based on the small cloud numerical control system and performs interactively cooperative machining between multiple numerical control machining devices for different workpieces to be assembled.

Abstract: A compact geared motor unit, capable of properly protecting an electric motor without disengaging gears or suspending the unit, even when a thrust force larger than an allowable value is generated. The geared motor unit 10 has an electric motor and a gear configured to generate a thrust force applied to the electric motor when transmitting a torque, and a control section for controlling the electric motor. The control section has a thrust load obtaining part which obtains a thrust load of the electric motor at predetermined timings or time intervals; a critical thrust load storing part which stores a critical thrust load of the electric motor; and a torque limiting part which electrically limits the torque of the electric motor when the obtained thrust load exceeds the stored critical thrust load.

Abstract: A vibration suppressing method and a vibration suppressing device are disclosed. After detection of chatter vibration using at least one vibration detecting device, a stable rotation speed for suppressing the chatter vibration is calculated using a stable rotation speed calculating device. A determination device then compares a detection value detected by the vibration detecting device, a predetermined setting value, and/or a current value that is calculated based on at least one of the detection value and the setting value, to a predetermined determination reference value that is previously set. Thereafter, the determination device determines whether or not the stable rotation speed is adopted in accordance with the comparison result, and changes rotation speed of the rotary shaft to the stable rotation speed if the stable rotation speed is adopted.

Abstract: A system for automatic chip breaking used in a cutting machine is illustrated, wherein the cutting machine has a cutter and a spindle actuator. According to control information, the spindle actuator controls the cutter to move along with a first axis to cut a workpiece, and the chips are produced. The system for automatic chip breaking includes a signal collection device, a controller, and an actuator. The signal collection device electrically coupled to the cutting machine collects the control information. The controller electrically coupled to the signal capturing device triggers a control signal according to the control information. The actuator installed between the spindle actuator and the cutter is electrically coupled to the controller, and controls the cutter to vibrate along with a second axis according to the control signal, wherein the second axis and the first axis have a specific angle.

Abstract: In a combination machining lathe, a workpiece holding device holds a workpiece in a manner that permits the workpiece to rotate around an axis parallel to a direction of a horizontal Z axis. A tool post holds a tool that comprises a holder and a bit. The tool held by the tool post is indexed to a position in which the longitudinal axis of the holder is parallel to an X axis direction. The bit of the tool held by the tool post is angled such that a longitudinal axis of the bit is disposed in a position tilted away from the X axis direction closer to a horizontal axis in a plane containing the X axis and the Y axis. A turning operation is performed while the tool and/or the workpiece are moved relative to each other in a direction of the longitudinal axis of the bit.

Abstract: The invention relates a method for reducing the eccentricity of the inner and outer surface (7, 9) of a hollow workpiece (i), for example a hollow shaft, rotatably clamped in machine tool (2), in which in one clamping a plurality of measurement data depending on the contour of the inner surface (7) of the hollow workpiece (i) are recorded, for example with the aid of ultrasound, using the recorded measurement data a desired surface (13) is calculated for at least a part of the outer surface (9), which has a reduced eccentricity with respect to the inner surface (7) and in a further step the rotating workpiece (i) is at least partially machined at the outer surface (9) thereof according to the desired surface (13).

Abstract: The invention relates to a machine for processing plastic workpieces. A machine housing surrounds a working chamber located between a workpiece spindle for rotationally driving the workpieces about a workpiece axis of rotation and a fast tool servo for producing an oscillating feeding movement of a rotary tool in the direction of the workpieces. The workpiece spindle is provided with a carriage which can be driven and is guided on at least two guide surfaces of a guiding arrangement in order to produce a relative advancing movement between the workpiece and the rotary tool. The advancing movement runs transversely with respect to the feeding movement and defining therewith a processing plane in which during processing the rotary tool engages with the workpiece. The guiding arrangement is mounted on the machine housing such that the processing plane extends between the two guide surfaces.

Abstract: Methods are described for calibrating a turning machine having a first rotatable portion or chuck for holding a workpiece. The first rotatable portion has a first feature associated therewith. The method comprises the steps of using a measurement probe to determine the position of the first feature, rotating the first rotatable portion through an angle, and using said measurement probe to determine the new position of the first feature. The extension of the technique to swivel head mill-turn machines is also described.

Abstract: A thread whirling device for producing a thread on a workpiece on a numerically controlled turning machine by a thread whirling method, having a retention structure for fitting the thread whirling device to the turning machine, a whirling head which is retained on the retention structure, has an opening and carries one or more cutters which are arranged peripherally on the edge of the opening, having a first drive device which is configured to drive the whirling head in a rotational manner about a first rotation axis which extends through the opening. The thread whirling device further includes a second drive device which is configured to drive the whirling head in a rotational manner about a second rotation axis which extends transversely relative to the first rotation axis, in order to orientate an angle between the first rotation axis and the spindle axis of the turning machine work spindle.

Abstract: A high precision micro/nanoscale machining system. A multi-axis movement machine provides relative movement along multiple axes between a workpiece and a tool holder. A cutting tool is disposed on a flexible cantilever held by the tool holder, the tool holder being movable to provide at least two of the axes to set the angle and distance of the cutting tool relative to the workpiece. A feedback control system uses measurement of deflection of the cantilever during cutting to maintain a desired cantilever deflection and hence a desired load on the cutting tool.

Abstract: A level difference or a uncut portion is prevented from being left between adjoining worked regions without forming any useless worked region. A lathe sectional shape forming unit (222) produces a sheet model of a lathe sectional shape in an X-Z plane on the basis of the solid model of a lathe shape formed by a lathe shape forming unit (220). A first/second step working sectional shape forming unit (227) produces sheet models of the worked sectional shapes of the first step and the second step on the basis of the sheet model of the lathe sectional shape, a step dividing position and an overlap amount. A first step disused shape deleting unit (229) and a second step disused shape deleting unit (230) delete the shape needing no work, from the sheet models of the worked sectional shapes of the first step and the second step.

Abstract: Machine tool systems and methods include methods of synchronizing cutting tools with a workpiece retainer. In some embodiments, the methods and systems provide at least two cutting tools that are synchronized to machine a common surface of a workpiece in a quick and efficient manner. A controller having a single line of code for controlling both cutting tools and the workpiece retainer may be used. The cutting tools may be synchronized such that they engage substantially opposite portions of the workpiece, thereby to reduce resulting forces in the workpiece that may tend to induce workpiece deflection and/or chatter. In other embodiments, a cutting tool is synchronized with a split workpiece holder that may be controlled to induce a compression, tension, or torsion pre-load in the workpiece.

Abstract: The different illustrative embodiments provide a method, computer program product, and apparatus for manufacturing a scleral contact lens. A number of dimensions for the scleral lens is generated based on a shape of an eye. An alteration to a first wavefront of light caused by the first wavefront of light traveling through a pupil of the eye is identified. A modification configured to be made to a posterior surface of the scleral lens is generated based on the alteration. The modification removes the alteration for a second wavefront of light traveling through the scleral lens and the pupil of the eye.

Abstract: A machine tool for machining a workpiece is provided with a cutting tool holder for holding a cutting tool and a rotation mechanism for holding the workpiece. One or both of the cutting tool holder and the rotation mechanism are movable on multiple axes so that the cutting tool is movable relative to the workpiece in multiple axial directions. A control device is provided for controlling the movement of one or both of the cutting tool holder and the rotation mechanism to synchronously vibrate the workpiece and the cutting tool relative to each other at a low frequency in multiple axial directions.

Abstract: A control panel 21 has a display screen 22. An operator turns a low-thrust pressing key 28 ON in the menu key group 26 displayed on the display screen 22. In this state, the operator turns an operating dial 32 of a manual pulse generator 31, thereby causing an encoder 34 to generate pulses. When the encoder 34 outputs a pulse signal as a command signal, and a servomotor 17 is driven in accordance with the command signal, the tailstock is advanced. With the distal end of a tailstock center contacting a center hole of the workpiece, the operator turns the operating dial 32, thereby finely adjusting the drive torque of the servomotor. Accordingly, the thrust of the tailstock center is finely adjusted, so that the tailstock center is pressed against the workpiece by a low thrust.

Abstract: A method for offsetting a part on a CNC machine comprises clamping a part to a fixture on a table for the CNC machine and machining a plurality of features and surfaces on the part. A plurality of global offsets are calculated for the fixture and the table based on location data of the plurality of features and surfaces. An actual part position on a global coordinate system for the CNC machine is determined by translating the fixture and the table by each the plurality of global offsets to the coordinate system. The actual part position is compensated to a nominal part position for each of the controllable axes of the CNC machine and a controller is programmed with a global offset compensation based upon the calculated offset for each controllable axis of the CNC machine to adjust each of the controllable axes to the actual part position.

Abstract: A machining method of machining a transfer optical surface on a optical element producing die having the transfer optical surface made of a material having Vickers hardness of Hv1500 or more, comprising: machining the transfer optical surface on the optical element producing die by cutting with a cutting tool, wherein a rake face of a tip of a blade of the cutting tool is set with an angle of minus values at an incising point on a surface to be machined.

Abstract: A lathe control system used for three dimensional curved surface machining includes an input module, a control module, a work table, a feeding module, a first sliding module, a second sliding module, and a cutter. The control module is electrically connected with the input module, the feeding module, the first sliding module, and the second sliding module. The first sliding module drives the feeding module to move along a first direction. The second sliding module drives the feeding module to move along a second direction perpendicular to the first direction. The cutter is positioned on the feeding module. The feeding module is capable of driving the cutter to move back and forth along a third direction under the control of the control module. The third direction is perpendicular to first and second direction.

Abstract: A machine tool includes a spindle side position measuring unit measuring a spindle axial position in a spindle radial direction relative to a first reference position and a tool side position measuring unit measuring the position of a tool post relative to a second reference position. The spindle side position measuring unit includes a first scale extending in the spindle radial direction and a first readout unit, one of a base end portion of the first scale and the first readout unit is disposed at a spindle axis and the other of the base end portion of the first scale and the first readout unit is disposed at the first reference position. One of a base end portion of a second scale and a second readout unit is disposed on the tool post and the other is disposed at the second reference position.

Abstract: A spiral cutting device includes a blade, a blade driving shaft, a guiding device, a driving device, and a controller. The blade is for processing a roller. The blade driving shaft drives the blade to move toward the roller. The guiding device moves in a guiding direction perpendicular to a moving direction of the blade. The driving device is movably supported on the guiding device and rotates the roller. The controller controls a feeding amount of the blade, a moving speed of the driving device, and a rotate speed of the roller to spirally cut the roller. When an outer surface of the roller is unfolded to a plane, the blade path of the blade is in sinusoidal shape or in cosinusoidal shape.

Abstract: A system, method, and computer program for monitoring a machine cycle. A method includes the steps of tracking an elapsed cumulative measure; comparing the elapsed cumulative measure with a cycle interrupt interval; interrupting a machining cycle at the cycle interrupt interval; and performing a local return to a defined position.

Abstract: The present invention relates to a machining system etc. capable of highly accurately machining a workpiece even in a case where the workpiece is deflected. A machining system 1 is configured with a lathe 10 having end portion supporting mechanisms 13, 15 for supporting both end portions of an elongated workpiece W horizontally, a tool rest 20 for holding a tool, a feed mechanism for moving the tool rest 20 in three orthogonal directions, and a control device 25 for controlling the feed mechanism, and a non-contact measuring device 30 for measuring the deflection shape of the workpiece W when the workpiece W is rotated. The control device 25 moves the tool along the deflection shape measured by the non-contact measuring device 30.

Abstract: An ultra-precision machining system includes a worktable, a first support device, a second support device, a rotating shaft, a cutting tool, a detector and a controller. The first support device is fixed on the worktable. The second support device is movably mounted on the worktable. The rotating shaft is rotatably connected to the first support device. The cutting tool is mounted on the second support device and is movable relative to the second support device along a vertical direction. The detector is fixedly connected to the first support device above the rotating shaft for detecting an axial deviation of the rotating shaft. The controller is configured for calculating the axial deviation of the rotating shaft and adjusting the position of the cutting tool relative to the rotating shaft to counteract the calculated axial deviation of the rotating shaft.

Abstract: In one aspect, the present invention provides an intraocular lens (IOL) that includes an optic comprising an anterior surface, a posterior surface, and a plurality of diffractive zones disposed on one of those surfaces. The surface having the diffractive zones has a profile characterized by a combination of aspheric and toric components.

Abstract: The cutting-edge position detecting method includes the steps of: under a condition in which the cutting edge of the tool is positioned in an image that is taken by a camera, performing first sampling scanning operations for the image in a predetermined scanning direction at predetermined first intervals, and recognizing points on an upper edge line of the cutting edge of the tool and points on a lower edge line thereof, based on brightness changing points upon the first scanning operations; connecting the recognized points on the respective two edge lines, so as to obtain two first-level approximate linear lines by a least-squares method; performing second sampling scanning operations for the respective two first-level approximate linear lines in directions perpendicular thereto at predetermined second intervals, and newly recognizing points on the upper edge line of the cutting edge of the tool and points on the lower edge line thereof, based on brightness changing points upon the second scanning operations

Abstract: Methods are described for calibrating a turning machine having a first rotatable portion or chuck for holding a workpiece. The first rotatable portion has a first feature associated therewith. The method comprises the steps of using a measurement probe to determine the position of the first feature, rotating the first rotatable portion through an angle, and using said measurement probe to determine the new position of the first feature. The extension of the technique to swivel head mill-turn machines is also described.

Abstract: A feeder for rods into a lathe by a motorized thruster for sliding and pushing a rod along a guide towards a processing lathe until the rod is taken by the lathe. An automatic control device actuates the thruster to advance according to a first thrust value and a sensor detects the movement of the thruster. If the sensor detects a minimum movement or no movement at all a thrust increase is commanded up to a predetermined maximum value. If the thruster does not move at all, this indicates jamming.

Abstract: A machine tool includes a bed, a main spindle, a first tool rest, a first tool, a first driving mechanism, a second tool rest, a second tool, a second driving mechanism and a control device. The main spindle is located over the bed. The first tool is mounted on the first tool rest. The second tool is mounted on the second tool rest. The control device controls the first driving mechanism and the second driving mechanism to drive the first tool rest and the second tool rest, respectively, such that the first tool and the second tool move along the same direction, and machine a processing surface of a workpiece in order.

Abstract: A sensor and monitoring system for performing work upon an inner diameter of a machined workpiece, such as a pipe turned by a lathe, with the work being viewed and/or recorded remotely. The system includes a sensing device having an elongated rod, at least one sensor mounted to a first end of the rod, and a power supply and a transceiver mounted to a second end of the rod, the sensor being positioned within the bore of the workpiece for performing work upon the inner diameter and the transceiver and power supply positioned external to the bore. A controller device is wirelessly connected to the transceiver for wirelessly receiving and sending communication signals to and from the sensor via the transceiver. The sensor may of various types, such as a linear touch probe, a distance sensing laser, a temperature, vibration, gas, noise, or ultrasonic sensor, or a camera.

Abstract: A machine tool includes a spindle side position measuring unit measuring a spindle axial position in a spindle radial direction relative to a first reference position and a tool side position measuring unit measuring the position of a tool post relative to a second reference position. The spindle side position measuring unit includes a first scale extending in the spindle radial direction and a first readout unit, one of a base end portion of the first scale and the first readout unit is disposed at a spindle axis and the other of the base end portion of the first scale and the first readout unit is disposed at the first reference position. One of a base end portion of a second scale and a second readout unit is disposed on the tool post and the other is disposed at the second reference position.

Abstract: There is provided a roll surface machining method and apparatus for using a cutting tool to carry out ultra-precision machining in the surface of a roll with a reduced amount of data. The apparatus and method for roll surface machining includes setting a machining start position of a cutting tool with respect to the surface of the roll by C-axis indexing of the roll and positioning of the roll in the axial direction (Z-axis direction) both with respect to the cutting tool. Also the cutting tool and the roll are moved relative to each other in the axial direction of the roll by position control using C-Z axis interpolation, thereby forming a three-dimensional pattern in the surface of the roll.

Abstract: There is provided a roll surface machining method and apparatus for using a cutting tool to carry out ultra-precision machining in the surface of a roll with a reduced amount of data. The apparatus and method for roll surface machining includes setting a machining start position of a cutting tool with respect to the surface of the roll by C-axis indexing of the roll and positioning of the roll in the axial direction (Z-axis direction) both with respect to the cutting tool. Also the cutting tool and the roll are moved relative to each other in the axial direction of the roll by position control using C-Z axis interpolation, thereby forming a three-dimensional pattern in the surface of the roll.

Abstract: A machining system 1 comprises a lathe 10 having end portion supporting mechanisms 13, 15 for supporting an elongated workpiece W horizontally, center rests 21 for supporting the middle portion of the workpiece W, an adjustment mechanism for adjusting the supported position of the workpiece W by adjusting the height positions of the center rests 21, a tool rest 20, and a control device 25, and a non-contact measuring device 30 for measuring the deflection amount of the workpiece W at portions thereof supported by the center rests 21 when the workpiece W is rotated. The control device 25 is configured to adjust the height positions of the center rests 21 by controlling the adjustment mechanism on the basis of the measured deflection amount, so that the height positions of both end portions of the workpiece W being rotated and the middle portion thereof become the same.

Abstract: A closed-loop feedback system and method for performing a machining operation. A tool's operational properties are measured in real-time. The operating parameters of the machining process are adjusted in real-time based on the measured properties.

Abstract: Methods are described for calibrating a turning machine having a first rotatable portion or chuck for holding a workpiece. The first rotatable portion has a first feature associated therewith. The method comprises the steps of using a measurement probe to determine the position of the first feature, rotating the first rotatable portion through an angle, and using said measurement probe to determine the new position of the first feature. The extension of the technique to swivel head mill-turn machines is also described.

Abstract: A reporting system, employing a microprocessor, tracks the operation of an on-vehicle brake lathe and provides records of the resurfacing operations performed by the lathe. Identification of the vehicle and wheel position of a brake disk to be resurfaced are inputted using an operator interface, and stored in a temporary memory. When tool bits of the lathe are positioned to set a depth of cut, a thickness monitor indicates the resulting thickness for the brake disk, which is compared to a minimum thickness specification for the inputted vehicle and wheel position to determine whether the disk can be resurfaced to meet the specification. If so, a cutting operation evaluator monitors a continuity checker that is responsive to contact of the tool bits and the disk to determine when the resurfacing operation is complete, at which time the collected data can be reported.

Abstract: A method for making a mold core for molding lenses of optical fiber connector, is provided. The method includes: providing a first fixture and a mold block, the first fixture defining a first cavity therein, a center of the first fixture located within the first cavity and deviated from a center of the first cavity; providing a lathe comprising a rotatable spindle and a drill bit aligning with the rotatable spindle; installing the blank in the first cavity of the first fixture, and mounting the first fixture to the spindle; machining a first mold cavity in the blank using the drill bit; reinstalling the blank in the first cavity by revolving the blank 180 degrees; and machining a second mold cavity in the blank using the drill bit, thereby obtaining a mold core having the first and the second mold cavities.

Abstract: The turning machine according to the present invention includes a displacement sensor (200) which measures a distance between an immobile reference point and a position of variable point which reflects the positional displacement of the tool, the immobile reference point being able to determine a relative positional correlation relating to a variable position of tools with the progress of machining of the workpiece (W) by the tool (421). In drawings the reference point is set up in the guide bush (90). And based on the measured result by the displacement sensor, the tool is moved so that the center height of the tool and the center line of the workpiece satisfy relatively the predetermined positional correlation. Accordingly, the center height deviation amount due to heat deformation and the like is corrected.

Abstract: The present invention provides methods and systems for chip breaking, controlling cutting tool wear, and the like in turning, boring, and other applications, including: engaging a workpiece with a cutting tool in a feed direction along a toolpath, superimposing an oscillation in the feed direction on the toolpath, and dynamically or non-dynamically varying the oscillation superimposed in the feed direction on the toolpath such that interrupted cuts and chips of a predetermined length or less are produced. These systems take full advantage of computer numerical control (CNC) methodologies.

Abstract: A toolholder with a controllable critical angle, such as a lead, trailing, rake or clearance angles, includes a tool spindle for retaining the toolholder in a tool rest of a machine tool. The machine tool includes at least one linear axis, for example, three mutually perpendicular axes, a rotary axis and a rotation axis. The rotary axis and/or rotation axis is controllable to move to a specified position in synchronization with a movement of one of the linear axes. An adaptor supports a cutting tool that is retained in the adaptor by a clamp. The cutting tool defines a critical angle, such as a lead angle, a trailing angle, a rake angle and a flank clearance angle, wherein the critical angle is corrected as a vector of movement of at least one of the linear axis is changed. In addition, the cutting tool can be positioned on opposite side of a centerline of rotation of the workpiece to effectively double the life of the cutting tool. A method of controlling a toolholder is also disclosed.

Abstract: The invention relates to a method of machining a face (3) of an ophthalmic lens (1) with a main machining step in which the position of a machining tool (8) is synchronised with the angular position of the ophthalmic lens (1) which is rotated around an axis of rotation (4) that is transverse to the face (3), in order to provide the face with a machined surface that is asymmetrical in relation to the axis of rotation (4) of the ophthalmic lens (1); and a complementary machining step in which a recess (22) is machined around the axis of rotation (4) of the lens (1).

Abstract: There is provided a V-groove machining method and apparatus which, by measuring the depth of a V groove cut by a cutting tool and correcting the cutting depth of the cutting tool based on the measurement data, enables high precision machining of four-sided pyramids having vertices of a uniform height.