Abstract: A material management apparatus for an additive manufacturing system comprises a build material supply system to supply build material to a building area for building an object by additive manufacturing. The build material supply system includes a first build material supply unit to supply build material from a first side of a building area and a second build material supply unit to supply build material from a second side of the building area, the second side opposing the first side. The material management apparatus also includes a controller to control the build material supply system to vary an amount of build material to be supplied via the first build material supply unit based on a detected difference between a first amount of material available for supply via the first build material supply unit and a second amount of material available for supply via the second build material supply unit.

Abstract: There is disclosed a build material supply unit, comprising: a supply chamber body enclosing a supply volume to contain a build material for additive manufacture; an electromagnetic distance sensor to determine a length parameter relating to a length of a beam pathway extending from an emitter of the sensor to a surface level of build material in the supply volume; and a reflector to reflect the beam pathway between the emitter and the surface level of build material; wherein the reflector is spaced apart from the emitter.

Abstract: A material management apparatus for an additive manufacturing system comprises a build material supply system to supply build material to a building area for building an object by additive manufacturing. The build material supply system includes a first build material supply unit to supply build material from a first side of a building area and a second build material supply unit to supply build material from a second side of the building area, the second side opposing the first side. The material management apparatus also includes a controller to control the build material supply system to vary an amount of build material to be supplied via the first build material supply unit based on a detected difference between a first amount of material available for supply via the first build material supply unit and a second amount of material available for supply via the second build material supply unit.

Abstract: There is disclosed a build material supply unit, comprising: a supply chamber body enclosing a supply volume to contain a build material for additive manufacture; an electromagnetic distance sensor to determine a length parameter relating to a length of a beam pathway extending from an emitter of the sensor to a surface level of build material in the supply volume; and a reflector to reflect the beam pathway between the emitter and the surface level of build material; wherein the reflector is spaced apart from the emitter.

Abstract: A combined chair and backpack includes a conventional folding lawn chair type frame having an upper transverse frame member pivotally connected to an upper portion of a pack frame. In an open orientation of the chair, the pack frame and chair back frame form an A-frame configuration to enhance stability. A removable reversible head rest/top pack assembly includes tubular side frame members which telescopically receive upper mounting rod portions of the pack frame. In an open condition, the head rest faces the chair, and in a closed condition the head rest is reversed such that the top pack is disposed in overlying relation with respect to the collapsed chair. A plurality of straps suspend a pair of insulated beverage and food storage bags from respective opposite arm rests. Internal stiffeners maintain the bags erect. In a closed configuration, quick release straps secure edge portions of the bags in adjacent relation.