A main spindle failure detection device for a machine tool includes a rotation speed detection unit, a reach time estimation unit, and a determining unit. The reach time estimation unit is configured to estimate a reach time in which the rotation speed of the main spindle reaches a predetermined rotation speed threshold using a non-linear model based on a rotation speed of the main spindle detected at a start of an inertia operation and a rotation speed of the main spindle detected after an elapse of preset measurement time from the start of the inertia operation. The determining unit is configured to compare the reach time estimated by the reach time estimation unit with a preset reach time in which the rotation speed reaches the rotation speed threshold, so as to determine a failure in the main spindle based on a result of the comparison.

A method for operating a hand-guided machine tool. The method contains detecting at least one linear acceleration value by means of the at least one sensor apparatus (6); subtracting the gravitational acceleration from the at least one linear acceleration value to form an adjusted linear acceleration value; integrating the adjusted linear acceleration value into a speed value; integrating the speed value into a distance value; multiplying the speed value by a time constant to form at least one further distance value; adding the distance value to the further distance value to form at least one total distance value; filtering at least one of the linear acceleration values and/or at least one of the speed values; comparing the total distance value with a defined limit value; and initiating a predefined action when the total distance value exceeds the defined limit value. A hand-held machine tool for carrying out such a method is also described.

A method for operating a hand-guided machine tool. The method contains detecting at least one linear acceleration value by means of the at least one sensor apparatus (6); subtracting the gravitational acceleration from the at least one linear acceleration value to form an adjusted linear acceleration value; integrating the adjusted linear acceleration value into a speed value; integrating the speed value into a distance value; multiplying the speed value by a time constant to form at least one further distance value; adding the distance value to the further distance value to form at least one total distance value; filtering at least one of the linear acceleration values and/or at least one of the speed values; comparing the total distance value with a defined limit value; and initiating a predefined action when the total distance value exceeds the defined limit value. A hand-held machine tool for carrying out such a method is also described.

Methods, systems, and apparatus, including medium-encoded computer program products, for computer aided design and manufacture of physical structures using subtractive manufacturing systems and techniques include, in one aspect, a method including obtaining information regarding a geometry of a part to be machined by a computer-controlled manufacturing system from a workpiece; based on the information regarding the geometry, identifying machine components to be used by the computer-controlled manufacturing system during machining the part; determining a position for the machining of the part with respect to at least one of the machine components, to even out wear on the machine components, based on data indicating previous positions, movements and wear of components associated with the computer-controlled manufacturing system; and providing instructions usable by the computer-controlled manufacturing system, wherein the instructions are configured to cause the computer-controlled manufacturing system to use the position for the machining.

Methods, systems, and apparatus, including medium-encoded computer program products, for computer aided design and manufacture of physical structures using subtractive manufacturing systems and techniques include, in one aspect, a method including obtaining information regarding a geometry of a part to be machined by a computer-controlled manufacturing system from a workpiece; based on the information regarding the geometry, identifying machine components to be used by the computer-controlled manufacturing system during machining the part; determining a position for the machining of the part with respect to at least one of the machine components, to even out wear on the machine components, based on data indicating previous positions, movements and wear of components associated with the computer-controlled manufacturing system; and providing instructions usable by the computer-controlled manufacturing system, wherein the instructions are configured to cause the computer-controlled manufacturing system to use the position for the machining.

A hard finishing machine for machining workpieces with at least one gearing, in particular a gear grinding machine, including a spindle rotated by a motor, wherein the spindle has, at a first axial position, a first sensor system for detecting rotation of the spindle at the first axial position, wherein the first sensor system is connected to a control unit for controlling rotation of the spindle. A second sensor system is arranged at a second axial position of the spindle, which is designed to detect rotation of the spindle at the second axial position, wherein the second sensor system is connected to a measuring device, wherein a further sensor system is arranged at the first axial position of the spindle, which is designed to detect rotation of the spindle at the first axial position and is also connected to the measuring device.

Methods, systems, and apparatus, including medium-encoded computer program products, for computer aided design and manufacture of physical structures using subtractive manufacturing systems and techniques include, in one aspect, a method including obtaining information regarding a geometry of a part to be machined by a computer-controlled manufacturing system from a workpiece; based on the information regarding the geometry, identifying machine components to be used by the computer-controlled manufacturing system during machining the part; determining a position for the machining of the part with respect to at least one of the machine components, to even out wear on the machine components, based on data indicating previous positions, movements and wear of components associated with the computer-controlled manufacturing system; and providing instructions usable by the computer-controlled manufacturing system, wherein the instructions are configured to cause the computer-controlled manufacturing system to use the position for the machining.

Methods, systems, and apparatus, including medium-encoded computer program products, for computer aided design and manufacture of physical structures using subtractive manufacturing systems and techniques include, in one aspect, a method including obtaining information regarding a geometry of a part to be machined by a computer-controlled manufacturing system from a workpiece; based on the information regarding the geometry, identifying machine components to be used by the computer-controlled manufacturing system during machining the part; determining a position for the machining of the part with respect to at least one of the machine components, to even out wear on the machine components, based on data indicating previous positions, movements and wear of components associated with the computer-controlled manufacturing system; and providing instructions usable by the computer-controlled manufacturing system, wherein the instructions are configured to cause the computer-controlled manufacturing system to use the position for the machining.