Hewlett-packard Development Company, L.p.

Brent Ewald

Matthew Allen Shepherd

Kenneth R Williams

William F Winters

Eric Collins

Wesley R Schalk

Arthur H Barnes

Matt G Driggers

Xavier Gasso Puchal

Pierre Joseph Kaiser

Alvin Post

Randall West

Michael Ewe

Eduardo Ruiz Martinez

Haseeb Yusef

John Geile

Jordi Gimenez Manent

Josh Shepherd

Michael Crockett

Saurabh Shripad Bhide

Michael Rode

Tristan Dudik

Drew Berwager

Micah Aberth

Joshua Shepherd

Randall Dean West

Mark H Mackenzie

Example systems relate to recoater movement. A non-transitory machine readable medium may contain instructions executable by a processor. The instructions may include instructions to change an action of a recoater in response to a determination that the recoater has reached a first location of a build area comprising build material. Instructions may further include instructions to lift the recoater in response to a determination that the recoater has reached a second location of the build area. Instructions may additionally include instructions to move the recoater over the second location at the lifted position, wherein the second location includes a build-up of the build material.

Recoater movement

In one example, a powdered build material supply system for additive manufacturing includes a supply deck, a dispenser to dispense a ribbon of powdered build material on to the supply deck, and a spreader to spread powdered build material from the ribbon over a work area adjacent to the supply deck.

Dispensing powdered build material for additive manufacturing

According to one aspect, there is provided apparatus for forming a layer of build material for three-dimensional printing. The apparatus comprises a spreader to spread a volume of build material to form a layer of build material on a build platform, wherein at least one end of the spreader is to remain a constant distance from a build material retaining wall in proximity to at least one edge of the build platform as the spreader is moved over the surface of the build platform, and further wherein at least a portion of the spreader is below the top of the retaining wall.

Forming a layer of build material

In some examples, preheat three-dimensional (3D) printer build material can include a heating plate of a 3D printer to preheat build material from below the build material, where the heating plate is located adjacent to a build platform of the 3D printer, and a heater-spreader carriage of the 3D printer to preheat the build material from above the build material and spread the preheated build material from the heating plate to the build platform.

Preheat three-dimensional (3D) printer build material

In an example, a method of fusing a 3D object layer with a stationary energy system positioned and a carriage that casts a shadow onto the work area includes, with one pass of the carriage moving over the work area at a constant speed, dispensing a liquid fusing agent onto a first layer of build material in a pattern corresponding to an object slice such that the exposure time of the patterned build material is unequal across the first layer and, with another pass of the carriage moving over the work area in the same direction and at the same constant speed as the first pass, spreading the next layer of build material over the first layer such that the exposure time of the patterned build material in the first layer is made equal across the first layer.

Fusing three-dimensional (3D) object layers

In some examples, with respect to feature protection for three-dimensional printing, a three-dimensional model of a three-dimensional object to be printed may be ascertained. A determination may be made as to whether a configuration of a three-dimensional model feature of the three-dimensional model matches a removable feature configuration from a set of removable feature configurations. Based on a determination that the configuration of the three-dimensional model feature of the three-dimensional model matches the removable feature configuration from the set of removable feature configurations, the three-dimensional model feature may be removed from the three-dimensional model to generate a modified three-dimensional model.

Feature protection for three-dimensional printing

Some examples include a fusing system for an additive manufacturing machine including a carriage movable across a build zone along the x-axis, a thermic source mounted to the carriage, and a roller mounted to the carriage adjacent to the thermic source. A longitudinal section of an exterior surface of the roller is exposed to indirect heat from the thermic source. The roller is controlled to rotate during and outside of a spreading operation of the build material. The carriage is to maintain the roller within a radiative heat transfer area of the thermic source.

Additive manufacturing roller within radiative heat transfer area

In order to have ensure a proper dosing of a 3D printing system, it is disclosed a feeding mechanism for feeding build material to a surface that comprises: a receptacle to receive build material; and an outlet of the build material having a substantially quadrilateral opening with a first dimension and a second dimension orthogonal to one another; the outlet further comprising a third dimension orthogonal to the first dimension and the second dimension defining the height of the outlet, and the feeding mechanism being to selectively feed build material from the receptacle through the outlet onto a surface as the feeding mechanism moves along a travel direction over the surface, being such travel direction parallel to the first dimension of the outlet, the feeding mechanism further comprising an actuator to modify the magnitude of at least one of the second dimension or the third dimension outlet.

Feeding mechanisms for 3D printers

An apparatus may, in an example, include a build platform to receive a dose of build material and a build material spreader to spread the dose of build material over a length of the build platform wherein lateral portions of the build material spreader have a diameter smaller than a medial portion of the build material spreader.

Build material spreaders

In an example, a method includes acquiring, at a processor, object model data for an object to be generated in additive manufacturing, the object model data representing the object as a plurality of polygons. A virtual object space enclosing the object may be inspected from a plurality of discrete source points in a plane. For each of a plurality of distances from each source point, it may be determined if a polygon face is encountered, and if so, a counter may be set based on whether the polygon face is oriented towards the source point or away from the source point. Based on a content of the counter, it may be determined if a volume enclosed between two distances from a source point is a volume of the object.

Determining object volumes in virtual object space

It is disclosed a 3D printing system and a build material spreading method for a 3D printer that comprises: moving a spreader in a first pass in a first direction over a pile of build material at a first separation distance from a dosing surface thereby sweeping a first amount of build material; modify the first separation distance by the distance adjustment unit to a second separation distance; and moving the spreader in a second pass in a second direction towards the build surface to sweep a second amount of build material in a direction towards the build surface.

Dosing mechanisms for 3D printers

According to one example, there is provided a method of distributing build material in a 3D printing system. The method comprises moving a build material support positioned below a hopper, the movement to cause build material stored in the hopper to be deposited on the build material support, and moving a recoater to spread build material from the build material support over a build platform to form a layer of build material thereon, and to return any excess build material back to the build material support.

Three-dimensional printing

According to an example, a recoater for a three-dimensional (3D) printer may include a cylindrical element having a surface to spread build material particles. The build material particles may have a specified average dimension and the surface may include a plurality of depressions that have dimensions that are smaller than the specified average dimension of the build material particles.

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Vancouver, WA, United States of America

Brent Ewald