Support substrates are used in certain additive fabrication processes to permit processing of an object. For additive fabrication processes with materials that are sintered into a final part, a multi-layer support substrate of interleaved support and interface layers is fabricated to support an object while reducing an impact of friction on shrinkage of the part during the sintering process.

Techniques for evaluating support for an object to be fabricated via an additive fabrication device are provided. In some embodiments, a three-dimensional representation of the object is obtained and a plurality of voxels corresponding to the representation of the object is generated. A first supportedness value may be assigned to a first voxel of the plurality of voxels based on an amount of support provided by a support structure to the first voxel, and a second supportedness value determined for a second voxel of the plurality of voxels, wherein the second voxel neighbors the first voxel, and wherein the second supportedness value is determined based on the first supportedness value of the first voxel and a weight value representing a transmission rate of supportedness through voxels of the plurality of voxels.

Techniques for evaluating support for an object to be fabricated via an additive fabrication device are provided. In some embodiments, a three-dimensional representation of the object is obtained and a plurality of voxels corresponding to the representation of the object is generated. A first supportedness value may be assigned to a first voxel of the plurality of voxels based on an amount of support provided by a support structure to the first voxel, and a second supportedness value determined for a second voxel of the plurality of voxels, wherein the second voxel neighbors the first voxel, and wherein the second supportedness value is determined based on the first supportedness value of the first voxel and a weight value representing a transmission rate of supportedness through voxels of the plurality of voxels.

A radiation beam field shaping device is made from a 3D printed frame that contains and gives shape to a granular material with bulk density of at least 3 g/cm.sup.3 and composed of metal grains having a size between 1 μm and 4 mm. The frame has a hole in the bottom with surrounding walls that defines the desired beam shape. In one implementation, the metal grains are composed of solid tungsten alloy ball bearings and/or tungsten alloy powder.

A radiation beam field shaping device is made from a 3D printed frame that contains and gives shape to a granular material with bulk density of at least 3 g/cm.sup.3 and composed of metal grains having a size between 1 μm and 4 mm. The frame has a hole in the bottom with surrounding walls that defines the desired beam shape. In one implementation, the metal grains are composed of solid tungsten alloy ball bearings and/or tungsten alloy powder.

A system and corresponding method to move build material in a three-dimensional (3D) printing system uses a gripper. The gripper is arranged to apply at least two opposing lateral forces to the build material. The at least two opposing lateral forces are applied to the build material, in conjunction with linear motion of the gripper, for at least a portion of a path the build material travels toward an extrusion head.

A system and corresponding method to move build material in a three-dimensional (3D) printing system uses a gripper. The gripper is arranged to apply at least two opposing lateral forces to the build material. The at least two opposing lateral forces are applied to the build material, in conjunction with linear motion of the gripper, for at least a portion of a path the build material travels toward an extrusion head.

Disclosed are selective layer deposition based additive manufacturing systems and methods for printing a 3D part. Layers of a powder material are developed using one or more electrostatography-based engines. The layers are transferred for deposition on a part build surface. One or more lasers are used to heat a region of the part build surface and a developed layer near the nip roller entrance. The developed layer is then pressed into the part build surface.

In a method of printing a 3D part in accordance with a selective deposition additive manufacturing process a first image portion of a flowable material is developed using a first electrophotographic engine. A second image portion of a resilient material is developed using a second electrophotographic engine. The first image portion is registered with respect to the second image portion to form a combined image layer comprising the first and second image portions on a transfer medium. The combined image layer is transfused from the transfer medium to a part build surface of a 3D part. The viscosity (Vr) of the resilient material is greater than or equal to three times the viscosity (Vf) of the flowable material, and/or the storage modulus (Er) of the resilient material is greater than or equal to three times the storage modulus (Ef) of the flowable material.

Embodiments of the present disclosure are drawn to additive manufacturing apparatus and methods. An exemplary additive manufacturing method may include forming a part using additive manufacturing. The method may also include bringing the part to a first temperature, measuring the part along at least three axes at the first temperature, bringing the part to a second temperature, different than the first temperature, and measuring the part along the at least three axes at the second temperature. The method may further include comparing the size of the part at the first and second temperatures to calculate a coefficient of thermal expansion, generating a tool path that compensates for the coefficient of thermal expansion, bringing the part to the first temperature, and trimming the part while the part is at the first temperature using the tool path.