Interface between CAD and Rapid Prototyping systems .1. A study of existing interfaces

Rapid prototyping processes produce parts layer by layer directly from the CAD model. The processes proceed by first slicing the geometric model of a part into layers. A standard interface is necessary to convey varied geometric descriptions from numerous CAD packages to Rapid Prototyping (RP) systems. The STL (STereoLithography) format is the most commonly used interface for this purpose. Unfortunately, it is an approximate model and is frequently not robust. Therefore, other interfaces are proposed to be used for RP systems. This paper, Part 1, will discuss several existing interfaces including the STL file for the RP systems. The strengths and weaknesses of these formats when used for RP systems are analysed. Furthermore, a new improved format is proposed by the authors in Part 2. In that paper, the design considerations and data structure of the new format are introduced.