Abstract: According to some aspects, a method is provided of removing debris from a liquid photopolymer in an additive fabrication device. According to some embodiments, a mesh of solid material may be formed in an additive fabrication device from a liquid photopolymer, and particles of debris present in the liquid photopolymer may adhere to the mesh. The debris may thereby be removed from the liquid photopolymer by removing the mesh from the additive fabrication device. The mesh may then be discarded.

Abstract: According to some aspects, a method of additive fabrication is provided wherein a plurality of layers are formed on a build platform, each layer contacting a container in addition to the build platform and/or a previously formed layer, the method comprising calculating, using at least one processor, one or more forces to be applied to a first layer of the plurality of layers subsequent to the first layer being formed, said calculating being based at least in part on a determined area of at least one portion of the first layer that overhangs a second layer of the plurality of layers, forming the first layer, the first layer being in contact with the container and in contact with a previously formed layer of the plurality of layers, and separating the first layer from the container by applying the calculated one or more forces to the first layer.

Abstract: According to some aspects, a method is provided of casting an object from a mold, the method comprising obtaining a mold comprising a hollow shell of rigid material, the material comprising a thermoset polymer having a plurality of pores formed therein, providing a metal and/or ceramic slurry into an interior of the mold, exposing at least part of the mold to a low pressure environment so that a net flow of gas is produced from the interior of the mold into the low pressure environment. According to some aspects, a method of forming a porous mold is provided. According to some aspects, a photocurable liquid composition is provided, comprising a liquid photopolymer resin, particles of a solid material, in an amount between 30% and 60% by volume of the composition, and a water-soluble liquid.

Abstract: Techniques of optically sensing fiducial targets, such as calibration patterns, within an additive fabrication device are provided. In some embodiments, fiducial targets may be disposed on a structure configured to contact source material of the additive fabrication device, the source material being a material from which the device is configured to fabricate solid objects. Indirect sensing means may be employed such that light emitted from a light source of the additive fabrication device scatters from the surface of a fiducial target. At least some of this scattered light can be measured by a sensor and used to determine a position of the fiducial target. In some embodiments, the fiducial target may be configured to move relative to the light source and/or sensor to provide additional information on the target's position via the light scattered from its surface.

Abstract: Techniques for generating a support structure for an object are provided. In some embodiments, one or more regions of the object are identified as one or more regions to which mechanical support is to be provided and one or more support points within at least a first region of the one or more regions are identified. A support structure may be generated for the object that comprises one or more support tips coupled to the object at the one or more support points, where the support tips being generated based at least in part on a direction normal to the surface of the object at the respective support point. Techniques for providing visual feedback to a user relating to an amount of support that a support structure is expected to provide during fabrication are also provided.

Abstract: According to some aspects, a method of additive fabrication is provided wherein a plurality of layers of material are formed on a surface of a build platform, each layer of material being formed so as to contact a container in addition to the surface of the build platform and/or a previously formed layer of material. The method comprises forming a layer of material in contact with the container and in contact with a previously formed layer of material, and subsequent to the forming of the layer of the material, separating the layer of material from the container by simultaneously applying a first force to the layer of the material in a direction perpendicular to the surface of the build platform, and a second force to the layer of the material in a direction parallel to the surface of the build platform.

Abstract: Techniques for directing light from a movable stage in an additive fabrication device are provided. According to some aspects, the movable stage may include a parabolic mirror onto which light may be directed at various different incident angles to produce light along different positions along an axis. In some cases, this axis may be perpendicular to a direction of motion of the movable stage.

Abstract: Techniques for film tensioning in additive fabrication are provided. According to some aspects, a film forming part of a container in an additive fabrication device may be tensioned by different forces along different axes. According to some embodiments, an adjustable tensioning system may be provided within an additive fabrication device that may couple to one or more components of a removable container comprising a film. The tension of the film may be adjusted by the additive fabrication device via the adjustable tensioning system and its coupling to the container.

Abstract: Techniques for producing a flat film surface in additive fabrication are provided. According to some aspects, a movable stage may be arranged beneath a container having a base that includes a flexible film. The movable stage may include a segmented member in which a number of segments are aligned along a common axis. The segmented member may maintain contact with the flexible film as the movable stage moves beneath the container, with the segmented member producing a flat surface of the flexible film, at least within a region above the movable stage. According to some embodiments, multiple segmented members may be provided within the movable stage, such as in parallel with one another.

Abstract: Multi-film containers for use in additive fabrication devices are provided. According to some aspects, a container may include multiple films that are at least partially detached from one another. In some embodiments, the multiple films may include films formed from different materials. As one example, an upper film may be formed so as to be relatively impermeable to substances within a source material of an additive fabrication device, whereas a lower film may be formed so as to provide desirable mechanical properties. In some cases, the multiple films may be commonly tensioned while being unattached to one another.

Abstract: Techniques for force sensing in additive fabrication are provided. According to some aspects, an additive fabrication device may include a force sensor configured to measure a force applied to a build platform during fabrication. A length of time taken for a layer of material to separate from a surface other than the build platform to which it is adhered may be determined based on measurements from the force sensor. Subsequent additive fabrication operations, such as subsequent motion of the build platform, may be adapted based on the determined length of time.

Abstract: According to some aspects, a laminated multi-material separation layer is provided for use in an additive fabrication device wherein layers of solid material are formed in contact with the separation layer by curing a liquid photopolymer. In some embodiments, the laminated multi-material layer may include an elastic first layer that aids in separation of cured photopolymer from the container in addition to a barrier layer on an upper surface that protects the first layer from exposure to substances in the liquid photopolymer that may not be compatible with the material of the first layer.

Abstract: Techniques for measuring a position of a build platform in an additive fabrication device are provided. Such techniques may include detecting the onset and/or dissipation of force applied to a build platform as it moves from being in contact with, to being out of contact with, a container. In some embodiments, the techniques described herein may be applied in a stereolithographic additive fabrication device. According to some embodiments, measurement of forces applied to a build platform may be used to provide for reliable and consistent measurements of the height of the build platform relative to a container by measuring such forces at various positions of the build platform and analyzing the pattern of the forces with distance from the container.

Abstract: According to some embodiments, a method of optimizing an additive fabrication process for an object is provided, the method comprising obtaining a representation of an intermediate form of the object, the intermediate form being an expected shape of the object when partially fabricated by the additive fabrication process, simulating one or more forces expected to be applied to the intermediate form of the object during the additive fabrication process, evaluating one or more results of the simulating step against one or more criteria, and adapting the additive fabrication process based at least in part on a result of the evaluating.

Abstract: According to some aspects, a method of additive fabrication wherein a plurality of layers of material are formed on a build platform is provided. The method may comprise forming a layer of material in contact with a container, and subsequent to the forming of the layer of material, rotating the container relative to the build platform and moving the build platform relative to the container, thereby creating an effective fulcrum about an axis, wherein the rotating of the container and moving of the build platform causes the layer of material to separate from the container. According to some embodiments, the container may be configured to rotate about a fixed axis. According to some embodiments, moving the build platform may comprise moving the build platform toward the container.

Abstract: According to some aspects, an additive fabrication device is provided. The additive fabrication device may be configured to form layers of material on a build platform, each layer of material being formed so as to contact a container in addition to the build platform and/or a previously formed layer of material, and may comprise a build platform, a container, and a plurality of mechanical linkages each independently coupled to the container and configured to move the container relative to the build platform.

Abstract: According to some aspects, a storage unit for storing a photopolymer resin is provided. The storage unit may comprise a photopolymer resin, a bottom face comprising at least one region of actinically transparent material, the actinically transparent material being actinically transparent with respect to the photopolymer resin, at least one wall extending upwards from said bottom face comprising at least one region of actinically opaque material, the actinically opaque material being actinically opaque with respect to the photopolymer resin, and a lid comprising the actinically opaque material and removably connectable to the at least one wall.

Abstract: The present disclosure relates generally to curable resins, in particular latent cure resins, and related methods for use in an additive fabrication (e.g., 3-dimensional printing) device.

Abstract: According to some aspects, an additive fabrication device is provided configured to form layers of material on a build platform, each layer of material being formed so as to contact a container in addition to the build platform and/or a previously formed layer of material. The additive fabrication device may comprise a container and a wiper, wherein the wiper comprises a wiper arm and a wiper blade coupled to said wiper arm using a pivoting coupling.