The self-propelled construction machine comprises a machine frame 2, supported by a chassis 1, which has wheels or tracks 1A, 1B. A milling drum 4 is arranged on the machine frame. The wheels or tracks and the milling drum are driven by a drive unit 8. A control unit 19 controls the drive unit 8 and a signal-receiving unit 18 detects at least one measurement variable M(t) which is characteristic of an operating state of the milling drum. The rotational speed of the milling drum is adapted, based on at least one measurement variable M(t), to the operating conditions of the construction machine in such a way that the milling drum is operated in a non-critical operating state. The adaptive open-loop control of the milling drum rotational speed allows the construction machine to be operated at an optimum operating point with respect to the milling drum rotational speed.

A method for confirming cutting tool's location includes: a position calculation unit basing on plural sleeve positions in a tool magazine to train and obtain training posture data and training signal strength data of each the sleeve position; and the position calculation unit sending a tool call command to move a target cutting tool among the cutting tool to a tool exchange position. The latter step includes: obtaining a posture data and a signal strength data of the target cutting tool; based on the posture data and the signal strength data, the position calculation unit comparing the training posture data and the training signal strength data to confirm a target sleeve location of the target cutting tool; and, rotating the tool magazine to move the target cutting tool from the target sleeve location to the tool exchange position. In addition, a machine system using the method is also provided.

A power tool includes a control for the motor of the power tool that senses an operating characteristic of the motor and controls the operation of the power tool based on the sensed characteristic. The sensed characteristic includes variations in reluctance of the motor. A controller may sense changes on load on the motor as a result of interaction between a working element such as a saw blade or drill bit and the work piece. The controlled operation may include variation in speed or torque or both, or may include stopping the motor. Emergency conditions may be sensed by changes in reluctance.

A power tool includes a control for the motor of the power tool that senses an operating characteristic of the motor and controls the operation of the power tool based on the sensed characteristic. The sensed characteristic includes variations in reluctance of the motor. A controller may sense changes on load on the motor as a result of interaction between a working element such as a saw blade or drill bit and the work piece. The controlled operation may include variation in speed or torque or both, or may include stopping the motor. Emergency conditions may be sensed by changes in reluctance.

Disclosed herein is a cyclonic system for performing subtractive machining in microgravity systems. The cyclonic system comprises: an enclosure, a blower, and a debris collection module to collect the debris from the milling machine. The enclosure includes a top plate, a base plate, and a tapered side wall joining the top plate to the base plate. The enclosure defines a chamber to house a milling machine having a cutter tool. The blower generates an airstream that induces a cyclonic airflow to achieve cyclonic separation of debris within the enclosure. In operation, the cyclonic airflow urges the debris from the milling machine toward the base plate and into the milling machine.

A method for drilling an element to be drilled by a drilling device and a cutting tool including drill margins and cutting edges. The method includes determining at least one load value representing overall drag due to internal friction of the drilling device and to friction of drill margins in the element to be drilled. Determining includes: stopping a drilling operation in progress; partial retraction of the cutting tool on a predetermined distance, the predetermined distance being chosen such that the cutting edges are no longer in contact with the element to be drilled; driving the cutting tool with predetermined cutting parameters; measuring at least one load value during the driving of the cutting tool with the cutting parameters before its cutting edges again come into contact with the element to be drilled and after stabilization of the load values, the measured load value representing the overall drag.

A method to ascertain a quality of a product formed by a subtractive manufacturing device from a workpiece includes: determining a deflection/test force relation for a deflection of the device; measuring an actually exerted machining force applied by the device to the workpiece; automatically determining a machining force reference for the actually exerted machining force; automatically evaluating whether the actually exerted machining force deviates from the machining force reference. If an actually exerted machining force deviates from the machining force reference, then the method uses the deflection/test force relation to automatically determine for the actually exerted machining force, at least one correction deflection of the device and automatically creating at least one corrected drive control signal to fully or partially reduce the correction deflection.

A workpiece cutting method of cutting a workpiece having a front side on which a plurality of crossing division lines are formed to define a plurality of separate regions where a plurality of devices are each formed is disclosed. The workpiece cutting method includes a workpiece cutting step of cutting the workpiece held on a first chuck table along the division lines by using a cutting blade, a dummy wafer cutting step of cutting a dummy wafer held on a second chuck table by using the cutting blade, a dummy wafer imaging step of imaging a cut groove formed on the dummy wafer in the dummy wafer cutting step, by using an imaging unit to thereby obtain a detected image, and a determining step of determining the condition of the cutting blade from the condition of chippings formed on both sides of the cut groove in the detected image.

A power tool includes a control for the motor of the power tool that senses an operating characteristic of the motor and controls the operation of the power tool based on the sensed characteristic. The sensed characteristic includes variations in reluctance of the motor. A controller may sense changes on load on the motor as a result of interaction between a working element such as a saw blade or drill bit and the work piece. The controlled operation may include variation in speed or torque or both, or may include stopping the motor. Emergency conditions may be sensed by changes in reluctance.

A system for surface machining of a curved part, the system including a chassis, a first and second roller, and a cutting tool. The first and second rollers each being coupled to the chassis and configured to contact the surface of a curved part. The cutting tool is disposed between the first and second rollers and coupled to the chassis such that a distance between the cutting tool and the chassis is adjustable.