Apparatus and method for fabrication of three dimensional objects

Abstract

digital fabrication apparatus of large built-volume three-dimensional (3D) objects.

What is claimed is: 
     
         1 . A digital fabrication apparatus, comprising:
 a workpiece platform assembly that is stationary and fixed to a frame of the digital fabrication apparatus;   the workpiece platform assembly comprising:   a floor plate assembly;   a diffuser plate;   thermally conductive pad; and   work-layer member that includes a work surface upon which a workpiece is fabricated;   the floor plate assembly is comprised of:   a floor plate with a bottom side and atop side;   a first set of reinforcement members that are mechanically connected to a second set of reinforcement members, which are mechanically connected to the bottom side of the floor plate of the floor plate assembly; and   a third set of reinforcement members that are mechanically connected to the top side of the floor plate of the floor plate assembly;   the floor plate, the first set of reinforcement members, the second set of reinforcement members, and the third set of reinforcement members stiffen the workpiece platform assembly and further, ultimately define a constant, fixed, XY-plane for the work-layer member in relation to a moveable fabrication tool.   
     
     
         2 . The digital fabrication apparatus as set forth in  claim 1 , wherein:
 the workpiece platform assembly is uniformly heated by a combination of a plurality of discrete heat sources and the heat diffuser plate, providing uniform heating of working surface of work piece platform assembly at a selected temperate.   
     
     
         3 . The digital fabrication apparatus as set forth in  claim 1 , wherein:
 the plurality discrete heat sources are comprised of a plurality of individual heating elements that are fixed onto the heat diffuser plate;   the heat diffuser plate rapidly conducts heat laterally from the plurality of individual heat elements and provides stiffness while enabling generally uniform distribution of heat emanated from a plurality of individual heat elements to thereby eliminate potential hot-spots on the heat diffuser plate;   wherein: the heat diffuser plate distributes heat to a larger surface area than a surface area of a heating element of the plurality of individual heat elements.   
     
     
         4 . The digital fabrication apparatus as set forth in  claim 3 , wherein:
 the thermally conductive pad is associated with a top surface of the heat diffuser plate, which further facilitates uniform lateral distribution of heat.   
     
     
         5 . A digital fabrication apparatus, comprising:
 positioning components for positioning a moveable fabrication tool along a Z-direction in relation to a defined XY-plane;   the positioning components include:   a moveable positioning frame having:   a moveable chassis;   a linking adapter connected to the chassis;   the linking adapter accommodating a guide bar that limits lateral movement of the moveable positioning frame, and accommodating a threaded rod of a Z-direction motive force mechanism that enable moveable positioning frame to move along a Z-direction by the Z-direction motive force mechanism; and   the moveable fabrication tool associated with the positioning frame is moved along the Z-direction with four Z-direction motive force mechanisms that operate together so that all corners of the positioning frame are simultaneously moved together to maintain a horizontal orientation of the positioning frame while moving along Z-direction.   
     
     
         6 . A digital fabrication apparatus, comprising:
 positioning components for positioning a moveable fabrication tool within an NY-plane;   the positioning components include:   a track mount assembly that has:
 a rigid gear rack that includes cogs; and 
 a track with a smooth surface; 
   a preloading adapter:   the preloading adapter is comprised of:
 a set of rollers that engage the track; and 
 a pinion coupled with an axel and driven by one of an X direction motive force mechanism and a Y direction motive force mechanism that engages the gear rack; 
   the X direction motive force mechanism and the Y direction motive force mechanism, providing synchronous rectilinear motion of a movable fabrication tool within an NY-plane.   
     
     
         7 . The digital fabrication apparatus as set forth in  claim 6 , wherein:
 the track mount assembly is comprised of a plurality of track mounting assemblies associated with a moveable positioning frame that, enable the moveable fabrication tool to move along an NY-plane of the moveable positioning frame by the X-direction motive force mechanism and the Y-direction motive force mechanism.   
     
     
         8 . The digital fabrication apparatus as set forth in  claim 6 , wherein:
 both the X-direction motive force mechanism and the Y-direction motive force mechanism are preloaded in relation to the track mounting assembly to eliminate backlash.