Abstract: According to some aspects, degradation of material in a sintering additive fabrication process may be mitigated or avoided by fabricating parts within a chamber that includes one or more thermal breaks. The thermal break may be implemented using a variety of structures, but generally allows material in the chamber close to the surface to be maintained at different temperatures than the material further from the surface. For instance, as a result of the thermal break, parts located within the material of the chamber that were formed earlier during fabrication may be kept cooler to avoid damage to the parts yet the upper surface (sometimes called the “build surface”) of unconsolidated material may be heated enough so as to require minimal additional energy exposure to trigger consolidation.

Abstract: According to some aspects, degradation of material in a sintering additive fabrication process may be mitigated or avoided by fabricating parts within a chamber that includes one or more thermal breaks. The thermal break may be implemented using a variety of structures, but generally allows material in the chamber close to the surface to be maintained at different temperatures than the material further from the surface. For instance, as a result of the thermal break, parts located within the material of the chamber that were formed earlier during fabrication may be kept cooler to avoid damage to the parts yet the upper surface (sometimes called the “build surface”) of unconsolidated material may be heated enough so as to require minimal additional energy exposure to trigger consolidation.

Abstract: Techniques are described for calibrating an optical system in an additive fabrication device using an image of the build surface within the device. These techniques allow calibration to be performed by imaging one or more calibration features generated on (or at) the build surface, which may include illuminated regions of the build surface, regions of the build surface on which solid material has been formed, and/or regions of the build surface to which energy has otherwise been directed thereby making those regions distinguishable from their surroundings. The calibration features may be produced (at least in part) by the optical system to be calibrated. The location of the calibration features within the image may be compared with the intended location of these calibration features, and corrections to the optical system determined based on any differences between the actual and intended locations.

Abstract: According to some aspects, degradation of material in a sintering additive fabrication process may be mitigated or avoided by fabricating parts within a chamber that includes one or more thermal breaks. The thermal break may be implemented using a variety of structures, but generally allows material in the chamber close to the surface to be maintained at different temperatures than the material further from the surface. For instance, as a result of the thermal break, parts located within the material of the chamber that were formed earlier during fabrication may be kept cooler to avoid damage to the parts yet the upper surface (sometimes called the “build surface”) of unconsolidated material may be heated enough so as to require minimal additional energy exposure to trigger consolidation.