The design of a STEP-NC compliant CAD/CAP/CAM system for the manufacture of rotational parts on a CNC turning centre

There have been many efforts to apply the STEP standard for process planning of a part with previous researchers developing feature extraction systems, for connecting the design stage with the process planning stage or information models for CAPP by using object-oriented modelling and other approaches. Several CAPP and CAM systems related to STEP-NC compliance are under implementation or commercialisation around the world but the focus for turning operations has been limited in the second aspect. This paper describes and illustrates a STEP compliant CAD/CAPP/CAM System for the manufacture of rotational parts on CNC turning centres. The information models to support the proposed system together with the information models defined in the ISO14649 standard used to create the NC programs are also described. A structured view of a STEP compliant CAD/CAPP/CAM system framework supporting the next generation of intelligent CNC controllers for turn/mill component manufacture is provided. Finally the authors proposed system is outlined by the modelling of a turn/mill workstation and through the use of user interface dialogs that depict the information held in the models. A case study component has been developed to prove the concept for using the milling and turning parts of ISO14649 to provide a turn-mill CAD/CAPP/CAM environment. The framework focuses on the standardisation of turn/mill product and manufacturing information models ensure that the content is consistent throughout the product life cycle enabling quality assured manufacturing.