South African Journal of Industrial Engineering
On-line version ISSN 1012-277X
BROWN, A.C.; DE BEER, D. and CONRADIE, P.. Development of a Stereolithography (STL) input and Computer Numerical Control (CNC) output algorithm for an entry-level 3-D printer. S. Afr. J. Ind. Eng. [online]. 2014, vol.25, n.2, pp. 39-47. ISSN 1012-277X.
This paper presents a prototype Stereolithography (STL) file format slicing and tool-path generation algorithm, which serves as a data front-end for a Rapid Prototyping (RP) entry-level three-dimensional (3-D) printer. Used mainly in Additive Manufacturing (AM), 3-D printers are devices that apply plastic, ceramic, and metal, layer by layer, in all three dimensions on a flat surface (X, Y, and Z axis). 3-D printers, unfortunately, cannot print an object without a special algorithm that is required to create the Computer Numerical Control (CNC) instructions for printing. An STL algorithm therefore forms a critical component for Layered Manufacturing (LM), also referred to as RP. The purpose of this study was to develop an algorithm that is capable of processing and slicing an STL file or multiple files, resulting in a tool-path, and finally compiling a CNC file for an entry-level 3D printer. The prototype algorithm was implemented for an entry-level 3-D printer that utilises the Fused Deposition Modelling (FDM) process or Solid Freeform Fabrication (SFF) process; an AM technology. Following an experimental method, the full data flow path for the prototype algorithm was developed, starting with STL data files, and then processing the STL data file into a G-code file format by slicing the model and creating a tool-path. This layering method is used by most 3-D printers to turn a 2-D object into a 3-D object. The STL algorithm developed in this study presents innovative opportunities for LM, since it allows engineers and architects to transform their ideas easily into a solid model in a fast, simple, and cheap way. This is accomplished by allowing STL models to be sliced rapidly, effectively, and without error, and finally to be processed and prepared into a G-code print file.