Abstract: Systems and methods for calibrating a solid-imaging system (10) are disclosed. A calibration plate (110) having a non-scattering surface (140) with a plurality (150) of light-scattering fiducial marks (156) in a periodic array is disposed in the solid-imaging system. The actinic laser beam (26) is scanned over the fiducial marks, and the scattered light (26S) is detected by a detector (130) residing above the calibration plate. A computer control system (30) is configured to control the steering of the light beam and to process the detector signals (SD) so as to measure actual center positions (xA, yA) of the fiducial marks and perform an interpolation that establishes a calibrated relationship between the angular positions of the mirrors and (x,y) locations at the build plane (23). The calibrated relationship is then used to steer the laser beam in forming a three-dimensional object (50).

Abstract: A solid imaging apparatus and method employing sub-pixel shifting in multiple exposures of the digitally light projected image of a cross-section of a three-dimensional object on a solidifiable liquid medium. The multiple exposures provide increased resolution, preserving image features in a three-dimensional object and smoothing out rough or uneven edges that would otherwise be occur using digital light projectors that are limited by the number of pixels in an image projected over the size of the image. Algorithms are used to select pixels to be illuminated within the boundary of each image projected in the cross-section being exposed.

Abstract: A solid imaging apparatus is provided that includes a replaceable cartridge containing a source of build material and an extendable and retractable flexible transport film for transporting the build material layer-by-layer from the cartridge to the surface of a build in an image plane. An operator using the device needs merely to remove a spent cartridge and replace it with a fresh cartridge to continue solid imaging virtually uninterrupted. The apparatus also includes the capability of withdrawing and inserting an imager without the operator having to perform a separate alignment step. A brush attached to the transport film and forming part of the cartridge provides for intra-layer removal of excess uncured build material. If desired, the apparatus can produce a fully reacted build. A high intensity UV source cures the build between layers. An injection molded build pad is designed to hold a build in an inverted position for improving the build.

Abstract: A disposable liquid build material feed cartridge for use in a solid imaging apparatus and a method of dispensing build material for use in such an apparatus with a radiation transparent build material carrier. The disposable liquid build material feed cartridge recovers unused liquid material from the radiation transparent build material carrier and recycles it through a filter into a supply reservoir for reuse. A dispersing roller is employed to express any entrapping air bubbles in the solidifiable liquid build material that is dispensed onto the radiation transparent build material carrier prior to its being imaged.

Abstract: A solid imaging apparatus and method employing build material transfer means effective to transfer solidifiable liquid build material from a first side of a radiation transparent build material carrier to a receiving substrate without entrapping air bubbles in layers of transferred solidifiable liquid build material and to cleanly separate the solidified build material from the radiation transparent build material carrier as each layer is formed during the layerwise building of a three-dimensional object. An expandable membrane forming an arcuate dome and a reciprocatible flexible film are employed to effect transfer of the solidifiable liquid build material.

Abstract: A method and apparatus for forming three-dimensional objects by laser sintering that includes the use of dense phase pneumatic conveying to internally recycle overflow powder, and to thoroughly blend overflow, recovered and virgin powder to provide a consistent powder feed mix to a laser sintering machine. Overflow powder from the laser sintering machine is recovered and recycled back into the laser sintering machine for reuse. The approach results in a compact and reliable powder recycle system with complete blending and minimum attrition to the handled powder.

Abstract: There is provided compositions and methods for producing three-dimensional objects by selective deposition modeling with a polar build material and a non-polar support material. The build material comprises a hydrocarbon wax material and a viscosity modifier, and the support material comprises a hydrocarbon alcohol wax material and a viscosity modifier. After the selective deposition modeling process has been completed, the object can be placed in a bath of polar solvent to remove the support material. The particular materials provided herein, and the post-processing methods associated therewith, provide for improved part quality of the three-dimensional object and for improved post-processing techniques. The three-dimensional objects can subsequently be used in a number of applications, such as patterns for investment casting.

Abstract: An inert gas dispenser for mounting to a process equipment functional window is provided to dispense an inert gas in a laminar flow at an effective velocity across the exposed surface to form a curtain of inert gas across the exposed surface to prevent a build-up of chemical by-product from the powder material during laser sintering. The gas flow rate is characteristic of a flow geometry having a Reynolds number below the turbulent range. The diffuser is used in a laser sintering system.

Abstract: A thermal management system is provided to control the preheating and cool down of a removable build chamber in a laser sintering system. A thermal management station controls preheating of a removable build chamber to heat the chamber to a temperature at or near the operating temperature of the laser sintering system. After insertion into the laser sintering system and completion of a build the thermal management station controls the cool down of the part cake within the removable build chamber after the chamber has been removed from the laser sintering system.

Abstract: An improved stereolithography apparatus for forming three-dimensional objects using multiple chambered resin vats and a quick disconnect mounting system to permit concurrent use of multiple photopolymer build materials and easy change over of resin vats is disclosed. The apparatus permits easy change over from multiple chambered vat use to single chamber vat use and vice versa or change over between multiple chambered vats.

Abstract: Solid imaging apparatus and methods for use are disclosed that reduce the amount of uncured solid imaging build material remaining on a completed build object following the completion of the solid imaging build process. The amount of uncured build material is reduced through the use of either an uncoating web that removes excess build material from the build object during the course of the building process or an ink jet source of build material that uses only as much build material as is necessary for the fabrication of the build part. Also disclosed is an imager assembly for use with such a solid imaging apparatus that incorporates two or more individual imagers in an array and accounts for variations in the intensity and alignment of adjacent imagers. The apparatus can be modified for semi-continuous operation and for integrating into a manufacturing operation, if desired.

Abstract: A solid imaging apparatus and method employing sub-pixel shifting in multiple exposures of the digitally light projected image of a cross-section of a three-dimensional object on a solidifiable liquid medium. The multiple exposures provide increased resolution, preserving image features in a three-dimensional object and smoothing out rough or uneven edges that would otherwise be occur using digital light projectors that are limited by the number of pixels in an image projected over the size of the image. Algorithms are used to select pixels to be illuminated within the boundary of each image projected in the cross-section being exposed.

Abstract: Solid imaging apparatus and methods for use are disclosed that reduce the amount of uncured solid imaging build material remaining on a completed build object following the completion of the solid imaging build process. The amount of uncured build material is reduced through the use of either an uncoating web that removes excess build material from the build object during the course of the building process or an ink jet source of build material that uses only as much build material as is necessary for the fabrication of the build part. Also disclosed is an imager assembly for use with such a solid imaging apparatus that incorporates two or more individual imagers in an array and accounts for variations in the intensity and alignment of adjacent imagers. The apparatus can be modified for semi-continuous operation and for integrating into a manufacturing operation, if desired.

Abstract: Solid imaging apparatus and methods for use are disclosed that reduce the amount of uncured solid imaging build material remaining on a completed build object following the completion of the solid imaging build process. The amount of uncured build material is reduced through the use of either an uncoating web that removes excess build material from the build object during the course of the building process or an ink jet source of build material that uses only as much build material as is necessary for the fabrication of the build part. Also disclosed is an imager assembly for use with such a solid imaging apparatus that incorporates two or more individual imagers in an array and accounts for variations in the intensity and alignment of adjacent imagers. The apparatus can be modified for semi-continuous operation and for integrating into a manufacturing operation, if desired.

Abstract: A stereolithography apparatus having a resin vat with resupply containers in one-way flow communication and a leveling container in two-way flow communication, an automatic offload cart to remove and replace build support platforms, an elevator assembly for supporting and releasably retaining a build platform removably attached to the stereolithography apparatus frame such that elevator forks supporting the build platform can be released into the vat and removed from the stereolithography apparatus with the vat, and a recoater assembly and recoater blade for mapping the resin surface in the vat and applying a fresh coating of resin to a cross-section being built in the vat.

Abstract: A material feed system for solid freeform fabrication. The build material is delivered in discrete or quantized amounts by a clamp feed system in a non-flowable state to the dispensing device and the material is then changed to a flowable state prior to being dispensed. The feed system can be used to build three-dimensional objects in color, if desired. The clamped feed system is integrated with a waste removal system.

Abstract: A stereolithography apparatus having a resin vat with resupply containers in one-way flow communication and a leveling container in two-way flow communication, an automatic offload cart to remove and replace build support platforms, an elevator assembly for supporting and releasably retaining a build platform removably attached to the stereolithography apparatus frame such that elevator forks supporting the build platform can be released into the vat and removed from the stereolithography apparatus with the vat, and a recoater assembly and recoater blade for mapping the resin surface in the vat and applying a fresh coating of resin to a cross-section being built in the vat.

Abstract: A solid imaging apparatus is provided that includes a replaceable cartridge containing a source of build material and an extendable and retractable flexible transport film for transporting the build material layer-by-layer from the cartridge to the surface of a build in an image plane. An operator using the device needs merely to remove a spent cartridge and replace it with a fresh cartridge to continue solid imaging virtually uninterrupted. The apparatus also includes the capability of withdrawing and inserting an imager without the operator having to perform a separate alignment step. A brush attached to the transport film and forming part of the cartridge provides for intra-layer removal of excess uncured build material. If desired, the apparatus can produce a fully reacted build. A high intensity UV source cures the build between layers. An injection molded build pad is designed to hold a build in an inverted position for improving the build.

Abstract: A stereolithography apparatus having a resin vat with resupply containers in one-way flow communication and a leveling container in two-way flow communication, an automatic offload cart to remove and replace build support platforms, an elevator assembly for supporting and releasably retaining a build platform removably attached to the stereolithography apparatus frame such that elevator forks supporting the build platform can be released into the vat and removed from the stereolithography apparatus with the vat, and a recoater assembly and recoater blade for mapping the resin surface in the vat and applying a fresh coating of resin to a cross-section being built in the vat.

Abstract: The invention relates to a method producing parts using laser sintering wherein a fusible powder is exposed to a plurality of laser scans at controlled energy levels and for time periods to melt and densify the powder and in the substantial absence of particle bonding outside the fusion boundary. Strength is improved up to 100% compared to previous methods. An example includes a relatively high energy initial scan to melt the powder followed by lower energy scans controlled to densify the melt and separated in time to dissipate heat to the surrounding part cake. The rate and extent to which the powder particles are fused together can be controlled so that each successive scan can be used to fuse the particles together in discreet incremental steps. As a result, the final dimensions of the part and its density and mechanical properties can be improved compared to conventional methods and part growth avoided.