Apparatus for making a stereolithographic object, methods for making a stereolithographic object, a method for locating the position of debris, and a method for monitoring consumption of a material for making a stereolithographic object

A method for displacing material in a stereolithographic apparatus, the method comprising:

• operating a positioner to move a build platform toward a material receiving surface;
• increasing deformation of a mechanical linkage between the build platform and the material receiving surface until a magnitude of a force indicated by a force sensing system is at least equal to a maximum force magnitude value;
• determining whether distance information satisfies a predefined distance condition while the mechanical linkage is deformed;
• and
• stopping the positioner if the distance condition is satisfied.

A method for controlling force during the fabrication of a stereolithographic object, the method comprising:

• receiving area information indicative of areas of a plurality of previously formed sections of a stereolithographic object;
• determining non-zero weightings for each of the plurality of areas based on a viscosity distance of a material used to make the stereolithographic object;
• and
• controlling a magnitude of force applied to the stereolithographic object during a displacement step by applying the non-zero weightings to the area information.