Abstract: Disclosed is a three-dimensional modeling apparatus (10) that builds up three-dimensional objects in a heated build chamber (24) by dispensing modeling material from a dispensing head (14) onto a base (16) in a pattern determined by control signals from a controller (140). The motion control components (18, 20) of the apparatus (10) are external to and thermally isolated from the build chamber (24). A deformable thermal insulator (132) forms a ceiling of the building chamber, allowing motion control of the dispensing head (14) in an x, y plane by an x-y gantry (18) located outside of and insulated from the build chamber (24). In the preferred embodiment, a material dispensing outlet (66) of the dispensing head is inside the chamber. Thermal isolation of the motion control components from the build chamber allows the chamber to be maintained at a high temperature.

Abstract: Disclosed is a modeling filament for use as feedstock in a fused deposition modeling liquifier, and a method for manufacturing the filament. The diameter and standard deviation of the filament are controlled to meet various tolerance requirements of jam resistance, slip resistance, model strength, liquifier overflow prevention and hysteresis-free transient response. Standard deviation of the filament diameter is matched to a filament target diameter. The resulting filament is used to form high-quality models.

Abstract: An apparatus has an extrusion head for extruding a bead of a liquified material at an extruded pump flow rate, an extrusion head motor for driving the extrusion head at a variable head velocity, a pump for providing liquified material to the extrusion head, and a control for providing control signals to both the extrusion head motor and the pump. The control signals control operation of the extrusion head and the pump so that the head velocity is slaved to an estimated profile of the extruded pump flow rate divided by a predetermined bead cross-sectional area.

Abstract: The present invention provides a method for controlling following error in a robotic system that moves a tool at a velocity along a path defined by an inputted set of vertices. The following error is controlled to be less than a tolerable error allowance. First, a subset of resonant vertices is identified from the inputted set of vertices. Each of the resonant vertices has a neighboring vertex for which a following error that results when the tool negotiates both the vertex and its neighboring vertex at an assigned vertex velocity might exceed the tolerable error allowance. Second, each vertex in the subset of resonant vertices is assigned a reduced vertex velocity. The reduced vertex velocity is selected so that the following error that results when the tool negotiates both the vertex and its neighboring vertex at the reduced velocities is less than the tolerable error allowance.