Abstract: A printer fabricates an object from a computerized model using a fused filament fabrication process. The exit of the nozzle may include a number of concentric rings, where each of which may be selectively opened or closed during extrusion to control extrusion properties such as a volume of extrudate or a mixture of material exiting the nozzle.

Abstract: In an aspect, a printer fabricates an object from a computerized model using a fused filament fabrication process and a metallic build material. An ultrasonic vibrator is incorporated into the printer to improve the printing process, e.g., by disrupting a passivation layer on the deposited material to improve interlayer bonding, and to prevent adhesion of the metallic build material to a nozzle and other printer components.

Abstract: A printer fabricates an object from a computerized model using a fused filament fabrication process and a bulk metallic glass build material. By using thermally mismatched bulk metallic glasses for an object and adjacent support structures, the interface layer between these structures can be melted and crystallized to create a more brittle interface that facilitates removal of the support structure from the object after fabrication.

Abstract: An additive manufacturing system uses electrohydrodynamic (EHD) printing techniques to form a metallic object based upon a digital model. A metal build material is melted within a reservoir and expelled through an outlet of an expeller in a controlled manner using EHD force to modulate surface tension on a meniscus of the liquid metal at the outlet of the expeller. Concurrently, a positioning robotics system moves the expeller relative to a print bed along a toolpath that forms the solidifying metal droplets into a net shape according to the digital model.

Abstract: Thermal parameters for an additive manufacturing process are estimated using computer modeling, and these thermal parameters are used to control the additive manufacturing process. For example, the thermal parameters may be estimated based on bulk material properties, object geometry, control signals to thermal components of a system, and so forth.

Abstract: A metallic electrohydrodynamic (EHD) three-dimensional printer fabricates an object while surface characteristics of the object are monitored. Sensors acquire data on surface characteristics, and feedback related to these surface characteristics is used to adjust the fabrication process, e.g., where the surface characteristics deviate from a target surface shape.