Data extraction from CAD model for rotational parts to be machined at turning centres

Abstract

Among the most important data produced and stored is product data. CAD data forms one of many contributors to product data. Although in most circumstances CAD data can be processed within the CIM environment by integrated software components to produce information like manufacturing data, assembly data, etc., there are a significant number of cases where an external CAD resource needs to be processed. An external CAD resource comes in the form of a neutral file format such as DXF, IGES, STEP, etc. Extracting the necessary information from an exchange file to generate manufacturing parameters thus becomes an important task. In this paper we present the results of our research efforts which were intended to extract information from the defacto industry standard DXF files to determine features existing on rotational parts to be machined on turning centres, and later utilise this information in the context of a software package implemented to develop a post-processing expert system. The feature extraction module presented in this paper, forms part of that expert system, which is named ASALUS (Aslan, 1995) and is illustrated in Figure 1. ASALUS is designed to manage the life cycle of rotational parts from the design all the way to the production by performing process planning using a generative approach and applying post-processing for two different CNC lathes.Among the most important data produced and stored is product data. CAD data forms one of many contributors to product data. Although in most circumstances CAD data can be processed within the CIM environment by integrated software components to produce information like manufacturing data, assembly data, etc., there are a significant number of cases where an external CAD resource needs to be processed. An external CAD resource comes in the form of a neutral file format such as DXF, IGES, STEP, etc. Extracting the necessary information from an exchange file to generate manufacturing parameters thus becomes an important task. In this paper we present the results of our research efforts which were intended to extract information from the defacto industry standard DXF files to determine features existing on rotational parts to be machined on turning centres, and later utilize this information in the context of a software package implemented to develop a post-processing expert system. The feature extraction module presented in this paper, forms part of that expert system, which is named ASALUS (Aslan, 1995) and is illustrated in Figure 1. ASALUS is designed to manage the life cycle of rotational parts from the design all the way to the production by performing process planning using a generative approach and applying post-processing for two different CNC lathes.