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Fyp Report Dpe 080001k Liang Yue

Oct 14, 2014

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yue-lee

PROJECT TITLE

Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

PROJECT NO: DPE034-02-10

SCHOOL OF ENGINEERING (MANUFACTURING)

Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

NANYANG POLYTECHNIC PROJECT REPORTCOURSE: DIPLOMA IN DIGITAL AND PRECISION ENGINEERING PROJECT TITLE: Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

PROJECT NO: DPE034-02-10

PROJECT DURATION: 06-12-10 TO 25-02-11

PROJECT MEMBER(S): NAME Liang Yue ADMIN. NO. 080001K ELECTIVE CNC Technology& Product Innovation and Rapid Prototyping

SUPERVISORS:

Mr. Wong Kim Tuck Mr. Lim Siok Khing

Proposed by: SEG (M): COMPANY: [] [ ]

DATE OF SUBMISSION:

SCHOOL OF ENGINEERING (MANUFACTURING)

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Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

NANYANG POLYTECHNIC PROJECT REPORT

SUMMARY

SCHOOL OF ENGINEERING (MANUFACTURING)This project is carried out for 12 weeks from 7th of September to 25th of December.Page 1 of 88

Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

During this time, I attended the structural training at the first week and I started my final year project during the following 11 weeks. My project title is Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology. The objectives of my project are to be able to operate CNC Turning machine and further optimize the machining process to get a high quality product. Firstly, I developed the three-dimensional model of my project components using UG software, including one steel component and two aluminum components which can be assembled together. Then I did the part programs of the three project components by the aid of Mastercam software. And lastly, I machined the project components out using OKUMA LB3000 CNC Turning machine. This report will cover what I have learned during the project weeks. Firstly, I will introduce some general concept of CNC Turning. Then I will introduce the important concept of cutting tool technology followed by step by step Mastercam programming procedure. And the most important part is the machining process and the optimization of the machining process based on the problem I encountered. The main objectives of optimization are to get a better surface finishing of the workpiece and reduce the time consumed. So I will explain the optimization of the machining process in four aspects: selection of tool insert, selection of cutting parameters, optimal toolpath planning and controlling during machine process.

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Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

NANYANG POLYTECHNIC PROJECT REPORT

ACKNOWLEDGEMENTS

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Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

SCHOOL OF ENGINEERING (MANUFACTURING)First of all, I would like to take this opportunity to give my special thanks to all the stuffs in NYP who have given me support and help during my project. Firstly, I would like to express my sincere thanks to Mr. Wong Kim Tuck, my supervisor of final year project, for giving me the strength and guidance to do this project and helping me with my preparation of presentation. I also would like to thank my co-supervisor, Mr. Lim Siok Khing, for kindly teaching me to do Mastercam Programming, setup of the machine and machining operation. I deeply express my sincere thanks to Mr. James Liang Hao Jie, Mr. Xu Jia Lu, and Mr. Yeo Teck Cher for direcly or indirecly support of my project whenever I have troubles, especiall when I have machining problem. My deep thanks to my accessors Mr. Lau Foo Yew and Mr. Tan Kah Lock for making time for my presentation and giving judgement. Last but not least, I would like to express thanks for all my lab mates and friends, especially who had given their support and encouragement to me. They always gave me a hand when I was in need. Finally, my most sincere and warmest thanks to all the people mentioned as above, who help me complete this project successfully.

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Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

NANYANG POLYTECHNIC PROJECT REPORT

TABLE OF CONTENTS

SCHOOL OF ENGINEERING (MANUFACTURING)Page 1 of 88

Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

Chapter 1 Introduction1.1 What is CNC 1.2 CNC Turning 1.4 Jaws 15 16 17 11 12 13

1.3 General Turning Operation 1.5 Toolholder

1.6 Flow of CNC Process

Chapter 2 Project Components2.1 Steel Component 19 21 23 2.2 Aluminium Component Part A 2.3 Aluminium Component Part B

Chapter 3 Cutting Tool Technology3.1 Tool Geometry 26 3.2 Cutting Data 3.3 Tool Life 27 28

3.5 Tool Materials 31

Chapter 4 Mastercam Programming4.1 Mastercam Software 34 35 4.2 Mastercam Programming

Chapter 5 Machining Process of Project Components5.1 Machine Specification 53 5.2 Machining Preparation 55 5.3 Machining Process 57 5.4 Finished Project Components 62

Chapter 6 Optimization of Machining Process6.1 Cutting Tool Selection 66 6.2 Cutting Parameters Selection 6.3 Toolpath Planning 69Page 1 of 88

68

Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

6.4 Machining Process

75

Conclusion 80 Appendix 82 Gantt Chart References 87 85

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Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

NANYANG POLYTECHNIC PROJECT REPORT

CHAPTER 1INTRODUCTION

SCHOOL OF ENGINEERING (MANUFACTURING)

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Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

1.1 What

is CNC

Previously, machines are operated manually by skilled machinists and it requires a great deal of operator skills and training to achieve high quality product. Manual machining is also relatively slow and expensive. Today, manual machine tools have been largely replaced by computer numerical control machine tools. The machines still perform the essentially the same functions, but movements of the machine tool are controlled electronically rather than by hand. So what is CNC? CNC is automated control of machine tools by a computer and computer program. In other word, a computer rather than a person will directly control the machine tool. A CNC machine tool differs from a conventional machine tool only in respect to the specialized components that make up the CNC system. The CNC system can be further divided into three subsystems: control, drive and feedback system. All of these subsystems must work together to form a complete CNC system. The heart of the CNC system is the control unit. This is the computer that stores and reads the program and tells the other components what to do. The control also acts as the user interface so that the operator can set up and operate the machine. The drive system comprises of the motors and screws that will finally turn the part program into motion. The function of feedback system is to provide the control with information about the status of the motion control system. The control can compare the desired condition to the actual condition and make corrections. Compared with manual machining, the CNC machining has many advantages: Reduce the setup time and lead time Programs are easy to edit, so programming process time is reduced Greater flexibility in complexity of components produced Higher accuracy and repeatability Simplified tooling and work holding system Able to achieve high productivity

However, there are still some limitations in CNC machining:Page 1 of 88

Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

CNC is slightly more expensive Depending on the complexity of machine tool, possibly more training is required for machine operators Greater maintenance cost

1.1 CNC TurningCNC turning is the process whereby a single point cutting tool is parallel to the surface of the workpiece. It is used to produce an object which has rotational symmetry about an axis of rotation and in most cases the tool is stationary with the workpiece rotating. The cutting tool follows the contour of the programmed tool path. CNC Turning uses the Cartesian coordinate system for programmed coordinates. The axis aligned with the spindle should be designated Z. The axis that is at a right angle to the spindle is designated X. Positive Z points to the right of the spindle, and the positive X direction points toward the back of the machine. This is done because the typical CNC turning center is constructed with the tool mounted on the back side.

X+

Chuck jaws

Z Workpiece

Z+

X

1.2 General

Turning Operations

A variety of machining operations can be performed on a CNC turning machine:Page 1 of 88

Development and Optimizing of Machining Process for CNC Turning with Appropriate Technologies and Methodology

Remove material from outer diameter of a rotating cylindrical workpiece to reduce the diameter of the workpiece

Remove material from the end face of the workpiece to produce a flat surface

U