Browsing by Subject "3D aliasing"

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    Adaptive Slicing of Solid Freeform Fabrication Processes
    (1994) Suh, Young Seok; Wozny, Michael J.
    The Solid Freeform Fabrication (SFF) process significantly reduces part specific setup manufacturing lead time. This process has been primarily used in fabricating prototypes for design visualization and verification. However, the major impact of this process on the future of manufacturing technology would be the possibility offabricating functional parts for end use. One ofthe obstacles to this goal is the insufficient accuracy ofthe final physical part produced by the process. From the software point of view, the major sources of the inaccuracy come from the inappropriate data transfer format and the 3D aliasing' or Stair-stepping' problem. The '3D aliasing' problem can be reduced by adapting the layer thickness to the geometry of the part. In this paper, the procedure of adaptive slicing from the exact representation ofthe part model is described. This will improve part accuracy and minimize building time especially for the parts with highly curved surfaces. The procedures are implemented and a comparison to the conventional uniform layer thickness method will be discussed.
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    Automating Sheet-Based Fabrication: The Conveyed-Adherent Process
    (1996) Thomas, Charles L.; Hayworth, Kenneth J.
    A new automated fabrication technology is described which breaks the fabrication process into spatially separate layer-formation and layer-bonding stages. The technique uses sheet material on a substrate as feedstock and cuts cross-section contours into the material before conveying the material on the substrate to a stacking station. Advantages include (a) speed, (b) versatility in fabrication materials, and (c) ability to fabricate hollows, embed or cast secondary materials, and selectively enhance or degrade material properties on a regional basis. A prototype fabricator has been built which automates all aspects ofthis process except weeding. Applications demonstrated using this machine include traditional rapid prototyping and visualization-model creation as well as functional machines taking advantage of embedding and cast-in-place techniques.