In an embodiment, a system includes a three-dimensional (3D) printer, a neutral feedstock, a p-doped feedstock, an n-doped feedstock, and a laser. The 3D printer includes a platen and an enclosure. The platen includes an inert metal. The enclosure includes an inert atmosphere. The neutral feedstock is configured to be deposited onto the platen. The neutral feedstock includes a halogenated solution and a nanoparticle having a negative electron affinity. The p-doped feedstock is configured to be deposited onto the platen. The p-doped feedstock includes a boronated compound introduced to the neutral feedstock. The n-doped feedstock is configured to be deposited onto the platen. The n-doped feedstock includes a phosphorous compound introduced to the neutral feedstock. The laser is configured to induce the nanoparticle to emit solvated electrons into the halogenated solution to form, by reduction, layers of a ceramic comprising a neutral layer, a p-doped layer, and an n-doped layer.

Systems and methods for forming an object using additive manufacturing. One method includes receiving a digital model of the object, predicting a shrinking characteristic or receiving a predicted shrinking characteristic of the object that will occur during thermal processing of the object, once formed, and generating, based on the shrinking characteristic of the object, instructions for forming a raft on which the object will be formed. The instructions for forming the raft are configured to form a raft having a shrinking characteristic that reflects the shrinking characteristic of the object.

A wall structure and a method for forming a wall structure is provided using three-dimensional printing of extruded building material applied to a surface of a building structure. According to one embodiment, the wall structure includes a pair of outer wythes spaced from an inner wythe. The outer wythes can include a core extending between the pair of outer wythes and toward the inner wythe. A protrusion can also extend toward the inner wythe a spaced distance from the inner wythe or entirely toward and adjoining the inner wythe. The core is configured with an inwardly facing spaced opposed surfaces of the outer wythes surrounding a vertically extending rebar, with grout surrounding that rebar. Horizontally extending support pins can be spaced parallel from each other and extend from the protrusions and into the inner wythe.

The present disclosure provides three-dimensional (3D) printing processes, apparatuses, software, and systems for the production of at least one desired 3D object. The 3D printer system (e.g., comprising a processing chamber, build module, or an unpacking station) described herein may retain a desired (e.g., inert) atmosphere around the material bed and/or 3D object at multiple 3D printing stages. The 3D printer described herein comprises one or more build modules that may have a controller separate from the controller of the processing chamber. The 3D printer described herein comprises a platform that may be automatically constructed. The invention(s) described herein may allow the 3D printing process to occur for a long time without operator intervention and/or down time.

A recoating unit (40) serves for equipping or retrofitting a device (1) for additive manufacturing of a three-dimensional object (2) by selectively solidifying a building material (15), preferably a powder, layer by layer. The device (1) comprises a recoater (16) movable across a build area (8) for applying a layer (31b, 32b) of the building material (15) within the build area (8) and a solidification device (20) for selectively solidifying the applied layer (31b, 32b) at positions corresponding to a cross-section of the object (2) to be manufactured. The device (1) is formed and/or controlled to repeat the steps of applying and selectively solidifying until the object (2) is completed. The recoating unit (40) comprises at least two recoating rollers (41, 42) spaced apart from each other in a first direction (B1) and extending into a second direction transversely, preferably perpendicularly, to the first direction, and a compacting and/or smoothing element (45) arranged between the two recoating rollers (41, 42) in the first direction (B1) and extending into the second direction. The recoating unit (40) is adapted to draw-out building material to a regular layer (31a, 32a), depending on the movement of the recoating unit into the first direction (B1) or into its reverse direction (B2), using the recoating roller (41, 42) arranged ahead in the respective moving direction (B1, B2), and to compact or smoothen the layer (31a, 32a) drawn-out by the recoating roller (41, 42) arranged ahead using the compacting and/or smoothing element (45).

A method for forming at least one three-dimensional article through successive fusion of parts of a powder bed, which parts correspond to successive cross sections of the three-dimensional article, the method comprising the steps of: providing a model of the at least one three-dimensional article; applying a first powder layer on a work table; directing a first energy beam from a first energy beam source over the work table causing the first powder layer to fuse in first selected locations according to corresponding models to form a first cross section of the three-dimensional article, where the first energy beam is fusing at least a first region of a first cross section with parallel scan lines in a first direction; varying a distance between two adjacent scan lines, which are used for fusing the powder layer, as a function of a mean length of the two adjacent scan lines.

A sensor may be to detect a property indicative of a print dead zone caused by a defect of build material to be used for generating the three-dimensional object or a malfunction of a heater that is to heat the build material, a build material distributor that is to provide the material, or a carriage. A processor may be to receive, from the sensor, dead zone data relating to the print dead zone, and to prevent the malfunction of the heater, the build material distributor, or the carriage, or to modify data representing the three-dimensional object to cause the three-dimensional object to be shifted such that three-dimensional object is to be printed outside the print dead zone.

An assembly includes an attachment arm having an axle extending from a first end of the attachment arm. The attachment arm of the detachable wheel assembly further includes a securing portion forming a second end of the attachment arm, the securing portion of the attachment arm including a pin positioned to extend above a first frame member of a gantry truss and to secure the first frame member between the pin and a portion of the attachment arm. The attachment arm also includes a frame support corresponding to a second frame member of the gantry truss such that the frame support supports the second frame member when the assembly is secured to the gantry truss, and the assembly includes a wheel rotatably attached to the axle of the attachment arm.

A disclosed system includes an additive manufacturing printer that performs a layer by layer three-dimensional printing process generating a casting mold based on a three-dimensional numerical specification. The numerical specification is based on a desired casting shape, including internal features such as hollow areas formed by cores, and is further based on a thermo-mechanical model of a casting process. The numerical specification describes variations in material and geometric properties of one or more layers of the casting mold corresponding to variations in the thermal and mechanical properties of the casting processes, as predicted by the thermo-mechanical model. The system may vary the thickness of features of the casting mold, based on predicted cooling rates, to reduce cooling non-uniformities and to provide for controlled, predictable cooling of the casting. The system may further generate trusses and heat sinks in the mold to respectively strengthen and weaken various features of the mold.

There is a truss structure, assembly and method of manufacturing a truss with a span L and a beam depth H. The truss having a main part includes a substantially planar top chord with a longitudinal centerline and webs connecting between the top chord and a bottom chord. The top chord is separated from the bottom chord by the webs. There is a top chord node where each web intersects with the centerline of the top chord and a bottom chord node where each web meets the bottom chord. At least two of the top chord nodes coincide with one another along the top chord. In use, the elements of the main part are in compression and the bottom chord includes a tension member.