Abstract: The invention relates to a 3D printer (10) having a coater (30) and a coater-cleaning device (50). The coater (30) has a container (32), which defines an inner hollow space (34) for receiving particulate building material, and a discharge region (36) for discharging the particulate building material, said coater being movable into a cleaning position in which the coater is arranged above the coater-cleaning device (50). The coater-cleaning device (50) has a wiper element (52) for wiping the discharge region (36), said wiper element being formed from an absorbent material which is configured to receive a liquid cleaning agent inside the material.

Abstract: A lift and turn drive unit, comprising a working element which may be linearly displaced and rotated relative to at least one housing element, whereby the working element is formed from at least one lifting element and at least one turning element.

Abstract: The invention relates to a device for balancing the weight carried by a robot arm of a robot. Said device comprises a fluid spring, rotably a pneumatic spring, and a control device for controlling the movements of the robot. The device is characterized by a pressure sensor which measures the pressure of the fluid of the fluid spring. Said device and the method provided for by the invention permit the exact adjustment and balancing of the movements of the robot arm.