Patent ID: 8226395

Claim:
An apparatus comprising: a build platform including a surface that is rigid and substantially planar; a conveyor formed of a sheet of material that moves in a path passing through a working volume proximal to the surface of the build platform, thereby providing a working surface on the sheet of material within the working volume, the conveyor including a motor to move the sheet along the path, wherein the sheet of material is flexible, wherein the path is a closed loop, and wherein the sheet of material is formed of a rigid material joined by a number of flexible links; an extruder including a chamber to receive a build material and an extrusion tip that extrudes the build material at a controlled volumetric rate; an x-y-z positioning assembly adapted to three-dimensionally position the extrusion tip within the working volume; and a controller electrically coupled to each of the build platform, the conveyor, the extruder, and the x-y-z positioning assembly, the controller operable to control the build platform, the conveyor, the extruder, and the x-y-z positioning assembly to fabricate an object in three-dimensions from the build material.