Abstract: The invention describes a laser printing system (100) for illuminating an object moving relative to a laser module of the laser printing system (100) in a working plane (180), the laser module comprising at least two laser arrays of semiconductor lasers and at least one optical element, wherein the optical element is adapted to image laser light emitted by the laser arrays, such that laser light of semiconductor lasers of one laser array is imaged to one pixel in the working plane of the laser printing system, and wherein the laser printing system is a 3D printing system for additive manufacturing and wherein two, three, four or a multitude of laser modules (201, 202) are provided, which are arranged in columns (c1, c2) perpendicular to a direction of movement (250) of the object in the working plane (180), and wherein the columns are staggered with respect to each other such that a first laser module (201) of a first column of laser modules (c1) is adapted to illuminate a first area (y1) of the object and a

Abstract: A modular building system wherein two profiled tubular members are connected to each other by two first cores which are slidably received in one of two elongated channels of one of the members, by two second cores which are received in the two channels at one end of the other member, by two non-circular posts which extend into sockets of first cores, through one wall of the one member and into sockets of the second cores when the one end of the other member is placed against the outer side of the one wall of the one member. First pins are used to secure the first cores to the one member and to the posts in their sockets, second pins are used to secure the second cores to the respective posts, and threaded fasteners are used to secure the second cores to the other member and/or to the posts.