Fabrication and Design Evaluation Using Cae Tools for a 3-Axis Vertical Milling Machine for Sculptured Surface Machining

Abstract

CNC technology has proved to be of great importance for manufacturing sector. The use of contemporary CNC systems along with higher computational and memory storage capacity of modern computer systems has redefined the shop floor automations strategies for modern manufacturing sectors. One of the biggest challenges today is how to make the CNC technology affordable, simpler and available to an extent that even a hobbyist/ occasional user can think of owing such technology. The aim of the present work is to evaluate the design of a new 3-axis CNC milling machine tool structure designed for sculptured surface machining using Finite Element Method (FEM) analysis in ANSYS. The machine tool structure constitutes a significant part of total cost of a CNC system. Thus a simpler cost effective machine tool design can greatly reduce the overall cost of a CNC system. The problem is not only about the reduction in the machine tool fabrication, but other costs associated with usage, repair and up-gradation or enhancements should also be lesser. Thinking this as an overall objective a simplified machine tool unit for sculptured surface machining has been designed, and under the present work an overall shape to the conceptual design has been given. The main standard components required for developing the prototype of machine tool structure has been selected following the approach of kind of loading the machine tool will be subjected. The magnitude of cutting forces has been calculated after fixing the range of cutting parameters and types of cutting tools to be used. A systematic study has been done for the selection of the drive motors and router as spindle drive. The objective of maximizing the tool traverse in X, Y and Z direction so as to enable to cutting tool to approach the maximum machining volume for material removal subject to the constraint of sizes of standard available machine components used in CNC machines has also been studied. Conceptual design for the machine tool which was achieved after a number of iterations, has been analysed using finite element method (FEM) using ANSYS for its stability under different loading conditions. The detailed FEM study has been carried out in two main phases, for analysis of overall machine structure and secondly for router assembly. As discussed in results and discussion, it has been found that the machine structure design is safe and the maximum level of deflections and stresses found during FEM analysis are in safe limit. The logical conclusions drawn from the present study have also been discussed along with the future scope of work in this area.