Abstract: A control method serves for controlling at least one solidification device of an additive manufacturing device for manufacturing a three-dimensional object by means of an additive layer build method in which at least one object is manufactured by repeated application of a layer of a building material to a build area and by selective solidification of the applied layer at positions corresponding to a cross-section of the object to be manufactured, wherein a gas having a plurality of flow directions which essentially are not aligned in the same direction flows across the build area.

Abstract: The invention relates to a computer-assisted method for generating a control data set for an additive layer manufacturing device. In a first step, a layer data set is accessed, wherein points are marked in the data model which correspond to an object cross-section and at which the bid-up material should be solidified. In a second step, the layer data set is modified in such a way that for at least a portion of the object cross-section, the number of beams required for solidifying the build-up material inside said portion is determined preferably automatically, according to quality specifications of the portion and/or a manufacturing time of the object. In a third step, the modified layer data set is provided as a control data set for the additive layer manufacturing device.

Abstract: A hydraulic stop for use in drilling or countersinking operations comprising a rotatable body for rotating a tool about its axis and a cage adapted to contact the surface of a workpiece when the tool has penetrated into the workpiece by a predetermined distance and to actuate a trip mechanism comprising a plunger-operated hydraulic valve as the tool penetrates the workpiece more than the predetermined distance, wherein the plunger is of adjustable length. When actuated the trip mechanism allows the body to shrink in length suddenly. The cage is axially adjustable in relation to the body to set the predetermined depth at which the trip mechanism actuates. Drainage means is provided comprising a plurality of holes spaced around the circumference of the body to which the cage is mounted to allow drainage of coolant whatever the axial position of the cage.