A machine tool includes a first spindle, a second spindle, and a joining means for joining the axial ends of workpieces gripped by the spindles to form a joined workpiece. The machine tool further includes an electric servomotor for moving the first spindle in the direction intersecting the axis of the first spindle, a current value detection means for detecting the current value of the electric servomotor, and a misalignment detecting means for detecting misalignment of a first workpiece and a second workpiece in the joined workpiece, based on the current value detected by the current value detection means when the joined workpiece gripped by the two spindles is rotated.

The method can include: assembling the part to be machined to a pallet into an assembly; measuring a centering of the part relative to the pallet; adjusting the centering of the part relative to the pallet based on said measuring; repeating the steps of measuring and adjusting until determining that the part is centered based on said measuring; and mounting the centered assembly to an automatic machining device and machining the part of the centered assembly with the automatic machining device.

A machining system includes a robot arm for changing a workpiece or inspecting a machined workpiece, and a probe that is attached to a distal end portion of the robot arm via a force sensor, where the robot arm is controlled such that the probe is arranged at a predetermined measurement position in contact with a side surface of a tool holder, where detection values of the force sensor are obtained over a predetermined period of time in a state where a main spindle is performing rotation operation, where an attached state of the tool holder is determined based on the detection values obtained over the predetermined period of time.

A high-speed low runout spindle assembly is provided. The spindle assembly includes a friction drive wheel configured to be coupled to an output shaft of a motor. The friction drive wheel is configured and disposed to directly contact a shank of a bit. A set of bearings is configured to contact the shank of the bit. A bit clamp assembly includes a clamp bearing having a central through-hole dimensioned to accept a lower portion of the shank of the bit. The bit clamp assembly is configured to hold the bit in contact with the set of bearings.

Provided is a misalignment determining device having a size thereof in an axial direction being made short. The misalignment determining device includes a case, a dial gauge, a holder portion, a support portion, a pivotal portion, a lever member, and a slide member. The slide member is placed in contact with a stylus of the dial gauge. While the pivotal portion and the lever member are rotated in synchronism with rotation of the holder portion, a pivot amount of the pivotal portion is transmitted to the slide member via the lever member, and based on an amount of movement of the slide member along an axis direction, the dial gauge determines the pivot amount.

A method and a device can measure machine error of an axis of rotation in a tool post having a touch probe without restriction of an angular range of an angle of rotation. Directions of a measurement plane and a measurement axis in a five-axis measurement are switched in correspondence to a range of the angle of rotation in a touch probe. The five-axis measurement is carried out by setting a position in a direction of a measurement axis in a measurement plane to a position where a reference sphere does not interfere with a lever rod of the touch probe as occasion demands. The five-axis measurement is carried out, for example, by setting the measurement plane to a position which is perpendicular to a line connecting an estimated center of the reference sphere and a center of a tip sphere or the lever rod of the touch probe.

A method of correcting an axial position of a workpiece support (1) used for removing material from a dental workpiece (2) which is held by the workpiece support (1) and is rotated together with the workpiece support (1) about a drive rotation axis (3) when material is being removed. The workpiece support (1) has at least two workpiece support parts (4, 5, 6) which can be separated from each other and connected to each other. One of the workpiece support parts (4, 5) has at least one compensation region (7) with a material projection (8) for introducing a compensation surface (9) by removing material, and the other workpiece support part (6) has a seating surface (10) for connecting to the compensation surface (9) in a form fitting manner.

A machine tool includes a first spindle, a second spindle, and a joining means for joining the axial ends of workpieces gripped by the spindles to form a joined workpiece. The machine tool further includes an electric servomotor for moving the first spindle in the direction intersecting the axis of the first spindle, a current value detection means for detecting the current value of the electric servomotor, and a misalignment detecting means for detecting misalignment of a first workpiece and a second workpiece in the joined workpiece, based on the current value detected by the current value detection means when the joined workpiece gripped by the two spindles is rotated.

A method of correcting an axial position of a workpiece support (1) used for removing material from a dental workpiece (2) which is held by the workpiece support (1) and is rotated together with the workpiece support (1) about a drive rotation axis (3) when material is being removed. The workpiece support (1) has at least two workpiece support parts (4, 5, 6) which can be separated from each other and connected to each other. One of the workpiece support parts (4, 5) has at least one compensation region (7) with a material projection (8) for introducing a compensation surface (9) by removing material, and the other workpiece support part (6) has a seating surface (10) for connecting to the compensation surface (9) in a form fitting manner.

A chuck grip accuracy checking method includes a gripping in which the measurement target is gripped on the claws, a moving step, and a measuring step. In the moving step, a movable member provided with a measurement instrument capable of measuring a run-out of the measurement target is moved by driving a movable-member driver to a position at which the measurement instrument can measure a run-out of the measurement target. In the measuring step, a run-out of the measurement target is measured by the measurement instrument, while the chuck is being rotated by driving a rotation driver.