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: The present application relates generally to photopolymer blends and related methods for use in an additive fabrication (e.g., 3-dimensional printing) device. According to some aspects, compositions are provided for the modification of a base photopolymer resin. The compositions may comprise colorant agent and/or cure-modifying composition. The compositions may be selected to cause, when combined with the base photopolymer resin to form a photo-curable composition, at least one property (e.g., color, depth of the cure) of the photo-curable composition to fall within a pre-determined range. Related kits and methods are also generally described.

Abstract: According to some aspects, techniques for determining a position of a build platform in an additive fabrication device are provided. According to some embodiments, forces resisting separation of the build platform from an opposing surface are measured and a position of the build platform with respect to the opposing surface is determined. In some embodiments, such forces may include fluid forces present during separation of a build platform from an interior surface of a liquid photopolymer container.

Abstract: According to some aspects, an additive fabrication device is provided comprising a container removably attached to the additive fabrication device, and a detector configured to sense a fluid level of photopolymer resin within the container, wherein said detector does not contact said container.