Development of Macro for 3D Machinable Parametric Freedom Surfaces

Abstract

The work done here is focused on the development of MACRO for the machinable 3D freeform surfaces, which can be produced on a 3 axis NC machine. The tool path is generated using a programming language. The tool path file has its input data from the STL file generated by the MACRO. Tool path file is used by the NC machine to produce the final product. This is achieved by the means of a program which is integrated with the MACRO API. The work involves various aspects such as analysis, creativity, and development. To develop an approach for integration of NC machining into casual wood working thereby, developing strategies to generate optimal tool path to reduce machine time. The work here tends to development of unlimited number of machinable surfaces just by the variation of the 3D curvature. It takes considerable amount of time to model the required surface of the part on which finally machining is to be done to generate the final product. In the present work a attempt has been made to develop three dimensional surfaces of a specific variety of parametric nature. A generalized MACRO has been developed to create the parametric pattern surfaces and to allow the user to develop these types of design features with minimum requirement of expertise in this field. Solid modelling systems are design with an API (Application Programming Interface) which form the canvas for writing MACRO. The API of Solidworks™ solid modeller has been used for this purpose. API provides the entire tool required to write and test this MACRO. The MACRO issue geometric instruction to the solid modeller based on parameter provided by user. The geometric instructions are then used to form a solid model of 3D design. Thus the MACROS has been created with a view of providing simple numeric parameter input which could be given on the user and then developing the complete surface. Thus making the all the required calculations in the background and the modelled surface is finally generated on the computer screen. This reduces the time, as well as the brain application of the user, and further it provides ease to the user. The validation of the parameterized design has been done in SolidWorks™. The freeform surface patterns created and parameterized are checked for machinability on a 3-axis milling lathe. These parts are non-symmetric sculptured surfaces as well as symmetric on a cylindrical base or a plane base. The parametric variation of the freeform surface design patterns are checked for machining on a 3 axis NC machine available.