Abstract: A constant density heat exchanger and method of operating are provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first plate is positioned at the first end of the housing and rotatable about an axis of rotation such that the first plate selectively allows a working fluid to flow into the inlet of the chamber. A second plate is positioned at the second end of the housing and rotatable about the axis of rotation such that the second plate selectively allows the working fluid to flow out of the outlet of the chamber. The first plate and the second plate are rotatable about the axis of rotation so as to hold a volume of the working fluid at constant density as a heat source imparts thermal energy thereto.

Abstract: An additive manufacturing apparatus can include a stage configured to hold a component formed by one or more layers of resin. A support plate can be positioned above the stage. A radiant energy device can be positioned above the stage. The radiant energy device can be operable to generate and project energy in a predetermined pattern. A feed module can be configured to operably couple with a first end portion of a resin support and can be positioned upstream of the stage. A take-up module can be configured to operably couple with a second end portion of the resin support and can be positioned downstream of the stage.

Abstract: A method for producing a component layer-by-layer includes: providing two or more resin handling assemblies, each including a resin support which has at least a portion which is transparent, each resin support defining a build surface located in a build zone of the respective assembly; executing a build cycle, including: depositing on each build surface radiant-energy-curable resin, the resin on each build surface being a unique material combination; positioning a stage relative to one of the build surfaces to define a layer increment; selectively curing the resin using applied radiant energy so as to define a cross-sectional layer of the component; separating the component from the build surface; cleaning at least one of the component and the stage; and repeating the cycle, for a plurality of layers, wherein at least one of the layers is cured in each of the build zone. Apparatus is described for carrying out the method.

Abstract: An additive manufacturing apparatus includes a feed module and a take-up module that are configured to operably couple with a foil. A stage is configured to hold one or more cured layers of a resin that form a component. A radiant energy device is positioned opposite to the at least one stage. The radiant energy device is operable to generate and project radiant energy in a predetermined pattern. An actuator is configured to change a relative position of the at least one stage and the foil. An accumulator is positioned between the feed module and the take-up module. The accumulator is configured to retain an intermediate portion of the foil to allow a first portion of the foil upstream of the accumulator to move at a first speed and a second portion of the foil downstream of the accumulator to move at a second speed during a defined time period.

Abstract: Various embodiments provide a method of additively manufacturing a part including depositing a layer of a powder on a working surface, depositing a binder solution on the layer of the powder at first locations, and depositing a sintering aid solution on the layer of the powder at second locations. The sintering aid solution comprises a sintering aid in a solvent. In various embodiments, the sintering aid enables an increased brown strength as compared to parts containing unbound powder. The method enables binders that provide high green strength to be used at the edges of the part, while also balancing a shortened debind time with an increased brown strength. Embodiments in which binder solution is deposited according to a predetermined pattern at second locations are also described.

Abstract: An additive manufacturing apparatus includes a support plate defining a window and a resin support configured to support an uncured layer of resin. A stage is configured to hold one or more cured layers of the resin to form a component positioned opposite a support plate. A radiant energy device is positioned on an opposite side of the resin support from the stage and is operable to project radiant energy in a grid through the window. The grid and/or pixels thereof are intelligently shifted to efficiently print one or more layers of a component.

Abstract: An additive manufacturing apparatus includes a support plate defining a window and a resin support configured to support an uncured layer of resin. A stage is configured to hold one or more cured layers of the resin to form a component positioned opposite a support plate. A radiant energy device is positioned on an opposite side of the resin support from the stage and is operable to project radiant energy in a grid through the window. The grid and/or pixels thereof are intelligently shifted to efficiently print one or more layers of a component.

Abstract: An additive manufacturing apparatus includes a support plate defining a window and a resin support configured to support an uncured layer of resin. A stage is configured to hold one or more cured layers of the resin to form a component positioned opposite a support plate. A radiant energy device is positioned on an opposite side of the resin support from the stage and is operable to project radiant energy in a grid through the window. The grid and/or pixels thereof are intelligently shifted to efficiently print one or more layers of a component.

Abstract: An additive manufacturing apparatus includes a support plate defining a window and a resin support configured to support an uncured layer of resin. A stage is configured to hold one or more cured layers of the resin to form a component positioned opposite a support plate. A radiant energy device is positioned on an opposite side of the resin support from the stage and is operable to project radiant energy in a grid through the window. The grid and/or pixels thereof are intelligently shifted to efficiently print one or more layers of a component.

Abstract: An additive manufacturing apparatus includes a support plate including a window. A stage is configured to hold one or more cured layers of the resin to form a component. A radiant energy device positioned on an opposite side of the support plate from the stage and operable to generate and project radiant energy in a patterned image through the window. An actuator is operably coupled with the stage and is configured to move the stage between a curing position and a removal position. The curing position can be offset from the removal position.

Abstract: An additive manufacturing apparatus is provided herein that includes a resin support configured to support a resin. A support plate includes a window. A stage is configured to hold one or more cured layers of the resin to form a component. Each cured layer is formed with the stage in a respective cure position. A radiant energy device is positioned on an opposite side of the resin support from the stage and is operable to generate and project radiant energy in a patterned image through the window. An actuator is operably coupled with the stage and is configured to move the stage in a Z-axis direction to place the stage in a removal position. The component contacts one of the resin support or the resin supported by the resin support in the removal position.

Abstract: An additive manufacturing apparatus is disclosed. The apparatus includes a build surface, at least a portion of which is transparent. The apparatus includes a first material depositor operable to deposit a curable resin to form a deposited resin layer on the build surface. A first sensing device is configured to measure the thickness of the deposited resin layer; and wherein the at least one sensing device is configured to generate a signal indicative of the thickness of the deposited resin layer. The first sensing device can be connected to a computer such that the additive manufacturing apparatus is configured to control the thickness of the deposited resin layer. The thickness of the deposited resin layer can be controlled such that it varies from side to side. The thickness can also be controlled such that it varies with time.

Abstract: An additive manufacturing apparatus includes a feed module and a take-up module that are configured to operably couple with a foil. A stage is configured to hold one or more cured layers of a resin that form a component. A radiant energy device is positioned opposite to the at least one stage. The radiant energy device is operable to generate and project radiant energy in a predetermined pattern. An actuator is configured to change a relative position of the at least one stage and the foil. An accumulator is positioned between the feed module and the take-up module. The accumulator is configured to retain an intermediate portion of the foil to allow a first portion of the foil upstream of the accumulator to move at a first speed and a second portion of the foil downstream of the accumulator to move at a second speed during a defined time period.

Abstract: A system includes a supply receptacle defining one or more supply receptacle sidewalls and an upwardly-facing receptacle opening, a piston positioned at least partially within the supply receptacle, where the piston, the upwardly-facing receptacle opening, and the one or more supply receptacle sidewalls at least partially define an interior space of the supply receptacle, and the piston is positionable between an extended position, in which the interior space has an extended volume, and a retracted position, in which the interior space has a retracted volume that is greater than the extended volume, and a dosing hopper positioned above and in selective communication with the interior space of the supply receptacle, where the dosing hopper is structurally configured to deliver build material to the interior space.

Abstract: An additive manufacturing apparatus includes: a build table, at least a portion of which is transparent, the build table defining a build surface; a material applicator operable to deposit a radio-energy-curable resin on the build surface; a stage positioned facing the build surface of the build table and configured to hold a one or more cured layers of the resin; one or more actuators operable to change the relative positions of the build table and the stage; a radiant energy apparatus positioned adjacent to the build table opposite to the stage, and operable to generate and project radiant energy on the resin through the build table in a predetermined pattern; a drive mechanism operable to move the build table so as to expose a new portion thereof for each layer; and material remover operable to remove remnants from the build surface. A method for using the apparatus is provided.

Abstract: An additive manufacturing apparatus is disclosed. The apparatus includes a build surface, at least a portion of which is transparent. The apparatus includes a first material depositor operable to deposit a curable resin to form a deposited resin layer on the build surface. A first sensing device is configured to measure the thickness of the deposited resin layer; and wherein the at least one sensing device is configured to generate a signal indicative of the thickness of the deposited resin layer. The first sensing device can be connected to a computer such that the additive manufacturing apparatus is configured to control the thickness of the deposited resin layer. The thickness of the deposited resin layer can be controlled such that it varies from side to side, i.e. across the width of the deposited resin layer in the transverse direction along the x-axis. The thickness can also be controlled such that it varies with time, i.e., in the machine direction along the y-axis.

Abstract: An additive manufacturing apparatus includes a support plate and a foil supporting an uncured layer of a resin. A stage is configured to hold a component of one or more cured layers of the resin. One or more actuators is operable to move the stage away from the support plate in a Z-axis direction. A radiant energy device is positioned opposite the stage such that the support plate is positioned between the radiant energy device and the stage. A foil interaction device includes a first pneumatic actuation zone and a second pneumatic actuation zone. Each of the first and second pneumatic actuation zones is configured to apply a force on a surface of the foil. The first and second pneumatic actuation zones are fluidly separable and configured to apply varied pressures relative to one another to the surface of the foil.

Abstract: An additive manufacturing apparatus includes a resin support configured to support a first resin and a second resin. A support plate includes a window. A stage is configured to hold one or more cured layers of the resin to form a component positioned opposite the support plate. A radiant energy device is positioned on an opposite side of the resin support from the stage and is operable to generate and project radiant energy in a patterned image through the window. An actuator assembly is configured to move the stage in a Z-axis direction and in a Y-axis direction.

Abstract: An engine body may include a piston body comprising a piston chamber and a regenerator body comprising a regenerator conduit. An engine body may include a working-fluid heat exchanger body comprising a plurality of working-fluid pathways fluidly communicating between the piston chamber and the regenerator conduit. Additionally, or alternatively, an engine body may include a heater body comprising a plurality of heating fluid pathways and the plurality of working-fluid pathways. The heating fluid pathways may have a heat transfer relationship with the working fluid pathways. The working-fluid pathways may fluidly communicate between the piston chamber and the regenerator conduit. The engine body may include a monolithic body defined at least in part by the piston body, the regenerator body, and the working-fluid heat exchanger body, and/or defined at least in part by the piston body, the regenerator body, and the heater body.

Abstract: An additive manufacturing apparatus includes a support plate and a foil supporting an uncured layer of a resin. A stage is configured to hold a component of one or more cured layers of the resin. One or more actuators is operable to move the stage away from the support plate in a Z-axis direction. A radiant energy device is positioned opposite the stage such that the support plate is positioned between the radiant energy device and the stage. A foil interaction device includes a first pneumatic actuation zone and a second pneumatic actuation zone. Each of the first and second pneumatic actuation zones is configured to apply a force on a surface of the foil. The first and second pneumatic actuation zones are fluidly separable and configured to apply varied pressures relative to one another to the surface of the foil.