A process planning method for improving build performance in stereolithography

A process planning method is presented to aid stereolithography users in selecting appropriate values of process variables in order to achieve characteristics desired in a part to be fabricated. To accomplish this, the method achieves a balance of objectives specified by geometric tolerances, surface finishes, and part build time, where the balance is specified through preferences on the objectives. Given these objectives and preferences, values are chosen for six process variables to best achieve the balance of objectives. The process variables include part orientation, layer thicknesses, and four recoat variables (Z-level wait time, sweep period, hatch overcure, and fill overcure). The process planning method is adapted from multiobjective optimization and utilizes empirical data, analytical models, and heuristics to quantitatively relate process variables to the objectives. Of particular importance, a new adaptive slicing algorithm has been developed. The process planning method is demonstrated on a part with non-trivial geometric features.

[1]  S. O. Onuh,et al.  Optimising Build Parameters and Hatch Style for Part Accuracy in Stereolithography , 1997 .

[2]  Charity M. Lynn,et al.  Accuracy models for SLA build style decision support , 1998 .

[3]  Douglas C. Montgomery,et al.  Response Surface Methodology: Process and Product Optimization Using Designed Experiments , 1995 .

[4]  Farrokh Mistree,et al.  THE COMPROMISE DECISION SUPPORT PROBLEM AND THE ADAPTIVE LINEAR PROGRAMMING ALGORITHM , 1998 .

[5]  Philip E. Reeves,et al.  Reducing the surface deviation of stereolithography using in‐process techniques , 1997 .

[6]  Herbert A. Simon,et al.  The Sciences of the Artificial , 1970 .

[7]  Debasish Dutta,et al.  An accurate slicing procedure for layered manufacturing , 1996, Comput. Aided Des..

[8]  Vito R. Gervasi.  Statistical Process Control For Solid Freeform Fabrication Processes , 1997 .

[9]  Prashant Kulkarni,et al.  An Integrated Software System for Process Planning for Layered Manufacturing , 1997 .

[10]  David W. Rosen,et al.  Build Style Decision Support for Stereolithography , 1997 .

[11]  Jan Helge Bøhn,et al.  Adaptive slicing using stepwise uniform refinement , 1996 .

[12]  André Dolenc,et al.  Slicing procedures for layered manufacturing techniques , 1994, Comput. Aided Des..

[13]  Han Tong Loh,et al.  Optimal orientation with variable slicing in stereolithography , 1997 .

[14]  Aaron P. West.  A decision support system for fabrication process planning in stereolithography , 1999 .

[15]  Paul F. Jacobs,et al.  Rapid Prototyping & Manufacturing: Fundamentals of Stereolithography , 1992 .