Could not download file: This paper is available to authorised users only.


R. Cavaleiro1, J. Antunes Simões2, M. Vieitas1

1Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa (PORTUGAL)
2Escola Superior de Tecnologia de Setúbal, Instituto Politécnico de Setúbal (PORTUGAL)
The innovation is a characteristic in the industry, and this leads to the use of the most advanced manufacturing methods, in order to meet the increasing on the demand from the customers, as well as the need for a rapid implementation of the production systems. Engineering supports the tools to provide solutions to this type of problems, namely developing new software or optimizing existing ones.
Currently, the most common problems that engineers and designers face in the area of machining is related with the high operations lead-time, data post-processing time, or even setup-time between machining operations.
In order to contribute to reduce those no-adding value times, this work intends to demonstrate a simple and concise method to build parts in a vertical machining center CNC 4-axis, using a reduced number of machining setups. The material fixture device used in this machining method is based in a rotary indexed axis, and a tailstock center. The machining is carried out without the physical intervention of the operator and a final piece with an overall quality quite acceptable is obtained.
By using this machining technique the presence of the operator is reduced to the minimum. Simultaneously through this work is demonstrated the feasibility of this method as an alternative to conventional rapid prototyping (by layers adding), regarding the available material, as well as the roughness and tolerances of the part.
In this study the SolidWorks CAD software and the MastercamX3 CAM software were used. The machining was carried out in a CNC 3 axis vertical machining center Cincinnati Arrow 500, with an indexed rotary axis.
The tests were carried with parts from the industry, namely from aeronautics and currently being manufactured using several setups. The material used in the tests was the high density polyurethane, since it has excellent machining characteristics.
Another major problem faced today by the machining industry is the lack of interchangeability of CNC controllers, namely the inability to transfer post-processed data between controllers of different manufacturers. In order to solve this problem, throughout this work was carried out a study on a new program format that is being developed, the STEP-NC. This program format allows the data transfer directly from the CAD / CAM software to the CNC controllers in a universal language, avoiding the need for post-processors.
keywords: cnc, cad/cam, step-nc.