Producing High Precision Additive Manufacturing Parts by Direct Printing of NURBS Surfaces

This paper provides a framework for the concept of direct printing of Computer Aided Design (CAD) data represented using Non-Uniform Rational B-Spline (NURBS). Preserving the topological information of CAD model eliminates the geometrical errors generated due to the approximations in the tessellation process. Additionally, the topological information can be used in the process of layer thickness selection, slicing, material deposition and post-processing to more accurately and efficiently determine their parameters. The potential advantages of implementing the direct usage of CAD data are the controllability and the scalability of the process which is highly crucial in the micro and Nano AM processes. A case study is presented in this paper in which a direct slicing procedure is implemented to find layer contours directly from the CAD model.