Abstract: Methods and systems, including medium-encoded computer program products, for generating internal structures usable in additive manufacturing include: obtaining a three-dimensional (3D) model of an object to be created by a 3D printer; determining a first slice of the 3D model; and generating first slice data that represents a portion of an internal structure in the first slice of the 3D model of the object, the slice data being usable for fabricating the first slice of the object during a 3D printing process, wherein the portion of the internal structure (i) includes cell structures corresponding to a respective point of a plurality of points with corresponding locations within the interior region, wherein each of the cell structures include an empty space inside the cell structure and (ii) includes a determined quantity of the cell structures based on an analysis of the 3D model.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for working with three-dimensional object models for printing. One of the methods includes determining a plurality of infill structures in a slice of an object; and determining a path for the tool-head to create the plurality of infill structures including: determining a first portion of the path for deposition of a first infill structure during a first time period; determining a second portion of the path for deposition of one or more second infill structures that are not adjacent to the first infill structure during a second time period; and determining a third portion of the path for deposition of a third infill structure that is adjacent to the first infill structure, wherein the second time period is determined to allow the first infill structure to cool before deposition of the third infill structure.

Abstract: Methods, systems, and apparatus, including medium-encoded computer program products, for generating internal structures usable in additive manufacturing include, in at least one aspect, obtaining a three dimensional (3D) model of a 3D object to be manufactured by a 3D extrusion printer; defining an infill structure for the 3D model, wherein defining the infill structure comprises defining an internal hull separated from an external hull by a separation distance, wherein the external hull corresponds to the 3D model, and defining walls between the external hull and the internal hull to form cells between the external hull and the internal hull; and providing the 3D model and the infill structure for the 3D model to generate tool path data for the 3D extrusion printer to build the 3D object in accordance with the 3D model and the infill structure for the 3D model.

Abstract: A fused filament fabrication three dimensional printing system includes a build platform, an extruder for one or more deposition materials, the extruder including at least one nozzle movable relative to the build platform, and a controller configured to control the relative movement between the build platform and the nozzle, and to cause material to be extruded out of the nozzle to form a 3D object on the build platform. The build platform includes a first plate on which the 3D object is formed, a second plate that is positioned vertically below the first plate and defines at least one gap between the first and second plates, and a heating element that is configured to heat the second plate. The first plate defines at least one opening that is configured to allow passage of material extruded from the nozzle into the at least one gap between the first and second plates.

Abstract: Methods, systems, and apparatus, including a method of multi-material stereolithographic three dimensional printing comprising, depositing a first material through a first material dispenser of a stereolithographic three dimensional printer onto an optical exposure window to form a first material layer; curing the first material layer to form a first material structure on a build head of the stereolithographic three dimensional printer; depositing a second material through the first material dispenser or a second material dispenser onto the optical exposure window to form a second material layer; and curing the second material layer to form a second material structure on the build head.