An additive material manufacturing (AMM) system is provided to deposit powder to a build. The AMM system includes a powder supply, and a delivery mechanism. The powder supply receives a first electrical charge having first polarity. The delivery mechanism receives a second electrical charge having second polarity opposite first polarity. The build receives a third electrical charge having the first polarity. The third electrical charge of the build is greater than the second electrical charge of the delivery mechanism. The delivery mechanism receives the electrically charged powder where it is retained thereto based on electrostatic attraction generated between the first polarity of the electrically charged powder and the second polarity of the delivery mechanism. The electrocharged powder is from the delivery mechanism to the build based on electrostatic attraction generated between the first polarity of the electrically charged powder and the second polarity of the build.

An additive material manufacturing (AMM) system is provided to deposit powder to a build. The AMM system includes a powder supply, and a delivery mechanism. The powder supply receives a first electrical charge having first polarity. The delivery mechanism receives a second electrical charge having second polarity opposite first polarity. The build receives a third electrical charge having the first polarity. The third electrical charge of the build is greater than the second electrical charge of the delivery mechanism. The delivery mechanism receives the electrically charged powder where it is retained thereto based on electrostatic attraction generated between the first polarity of the electrically charged powder and the second polarity of the delivery mechanism. The electrocharged powder is from the delivery mechanism to the build based on electrostatic attraction generated between the first polarity of the electrically charged powder and the second polarity of the build.

A flow meter includes a pair of ultrasonic transducers. Each transducer includes a housing, a piezoelectric crystal disposed within the housing, and a mini-horn array coupled to the housing. The mini-horn array, which may be formed via a 3D printing technique, includes an opening-free enclosure, a closed cavity inside the enclosure, and a plurality of horns enclosed within the closed cavity. The horns include a horn base portion adjacent to a proximal end surface of the cavity and a horn neck portion that extends from the base portion in a direction away from the piezoelectric crystal and towards a distal end surface of the cavity. The horn neck portions are separated by spaces within the cavity, wherein the spaces between the horn necks may be filled with powder.

In one example, a system for loading build material into a portable build unit having a platform on which objects are printed and a build material supply container next to the platform. The system includes a build material dispenser, a conveyor to move the build unit and/or the dispenser, and a controller operatively connected to the dispenser and the conveyor. The controller is programmed to, with the build unit and the dispenser in a fill position, cause the dispenser to dispense build material into the supply container, cause the conveyor to move the build unit and/or the dispenser to and/or from the fill position, and, while the conveyor moves the build unit and/or the dispenser to and/or from the fill position, cause the dispenser to dispense build material on to the platform.

The devices, systems, and methods of the present disclosure are directed to powder spreading and binder distribution techniques for consistent and rapid layer-by-layer fabrication of three-dimensional objects formed through binder jetting. For example, a powder may be spread to form a layer along a volume defined by a powder box, a binder may be deposited along the layer to form a layer of a three-dimensional object, and the direction of spreading the layer and depositing the binder may be in a first direction and in a second direction, different from the first direction, thus facilitating rapid formation of the three-dimensional object with each passage of the print carriage over the volume. Powder delivery, powder spreading, thermal energy delivery, and combinations thereof, may facilitate consistently achieving quality standards as the rate of fabrication of the three-dimensional object is increased.

A three-dimensional laminated and shaped object having a graded composition is accurately shaped. A three-dimensional laminating and shaping apparatus for shaping a three-dimensional laminated and shaped object having a graded composition by laminating a plurality of kinds of materials includes a material supplier that supplies the materials while executing a scan, an irradiator that irradiates the materials with a beam, and a controller that controls the material supplier. The controller controls the material supplier to supply, to a predetermined scanning area of a material scanning area, a necessary amount of a predetermined material for laminating one layer of the three-dimensional laminated and shaped object at a predetermined number of times.

A method comprising dividing a build model comprising an object model arranged within a virtual volume into cross-sectional layers along a vertical axis. The layers represent layers of an additive manufacturing process. A set of base layers is identified with each of the base layers comprising a flat bottom surface of the object model. A base characteristic is assigned to the set of base layers. A set of bulk layers is identified which excludes the set of base layers. A bulk characteristic is assigned to the set of bulk layers. An additive manufacturing apparatus is instructed to build a build cake according to the build model, layers and assigned characteristics, so a fluid agent is deposited at a first rate for the set of bulk layers having the bulk characteristic and a second rate, slower than the first rate, for the set of base layers having the base characteristic.

A printing apparatus for printing a three-dimensional object. The printing apparatus includes an operative surface and a plurality of supply hoppers configured for dispensing a powder. The powder is configured to be melted by an energy beam. The supply hoppers are configured to form a plurality of vertically-aligned powder beds adjacent to one another on the operative surface simultaneously. An energy source is configured to emit an energy beam onto each powder bed simultaneously to melt or fuse a topmost layer of the powder bed onto an underlying powder bed layer or substrate.

Techniques are described for consistently moving powder from a hopper into a trough for subsequent delivery into a build area of an additive fabrication system. A powder delivery apparatus may comprise a hopper, a trough, and a doser. The doser may be configured to rotate about an axis and may include a recess that, when the doser is rotated about the axis, travels into and out of the hopper and into and out of the trough. As a result, when powder is present in the hopper, the recess may carry powder from the hopper to the trough when the doser rotates. The trough and doser may be configured so that when the trough contains the desired amount of powder for recoating, the doser does not transfer additional material from the hopper into the trough. As a result, the amount of powder in the trough may be self-regulating.

Techniques are described for consistently moving powder from a hopper into a trough for subsequent delivery into a build area of an additive fabrication system. A powder delivery apparatus may comprise a hopper, a trough, and a doser. The doser may be configured to rotate about an axis and may include a recess that, when the doser is rotated about the axis, travels into and out of the hopper and into and out of the trough. As a result, when powder is present in the hopper, the recess may carry powder from the hopper to the trough when the doser rotates. The trough and doser may be configured so that when the trough contains the desired amount of powder for recoating, the doser does not transfer additional material from the hopper into the trough. As a result, the amount of powder in the trough may be self-regulating.