DESIGN AND ANALYSIS OF A SMALL-SCALE COST-EFFECTIVE CNC MILLING MACHINE

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ABSTRACT

This thesis aims to explore the theories and techniques behind procedures of developing a high precision cost-effective mini CNC milling machine. This newly designed machine tool can be widely used in electrical and medical industry for making small parts and engraving small features. Various structures were explored and compared during the design stage. Different commercial products were carefully selected and purchased from the Nigerian market. PMAC from Delta Tau was used as the motion controller. Different setup and configuration issues using PMAC were explored. A newly designed motion controller using Arduino and TI MSP430 was also tested and implemented as a replacement of PMAC to reduce cost. Fabricated prototype machine was calibrated and tested under various self-testing procedures to meet industrial standard. Comprehensive cost analysis and profit estimation was conducted after completion of the machine tool prototype.

CHAPTER ONE

INTRODUCTION

With the on-going development of technology and economy, new industrial requirements such as high precision, good quality, high production rates and low production costs are increasingly demanded. Most of such requirements, including dimensional accuracy, conformance to tolerances of finished products and production rate can be met with better machine tools. With the help of CNC technology, machine tools today are not limited to human capabilities and are able to make ultra-precision products down to nano scales in a much faster manner.

The traditional design philosophy of machine tools is multifunctionality and highest precision possible. For example, a shank with spindle together with tailstock can be added onto a standard three axis vertical milling machine to become a multifunctional drilling-milling-turning machine, meaning the machine tool is designed to be used for multiple instead of single purposes. However, with the dramatic increase of industry varieties and the growing demand of miniature products, these general purpose machine tools are not efficient, either in terms of machine time or cost, in manufacturing products with special sizes and precision requirements. Generally.