UNIVERSITI TEKNIKAL MALAYSIA MELAKA DEVELOPMENT OF INTERACTIVE MACHINING PROCESS DESIGN AND MACHINING TIME CALCULATION

Transcription

1 UNIVERSITI TEKNIKAL MALAYSIA MELAKA DEVELOPMENT OF INTERACTIVE MACHINING PROCESS DESIGN AND MACHINING TIME CALCULATION This report submitted in accordance with requirement of the Universiti Teknikal Malaysia Melaka (UTeM) for the Bachelor Degree of Manufacturing Engineering (Manufacturing Management) with Honours. By MOHAMAD IZWAN BIN ISHAK FACULTY OF MANUFACTURING ENGINEERING APRIL 2010

2 UTeM Library (Pind.1/2005) UNIVERSITI TEKNIKAL MALAYSIA MELAKA BORANG PENGESAHAN STATUS TESIS* JUDUL: Development of interactive machining process design and machining time calculation SESI PENGAJIAN: Mohamad Izwan Bin Ishak Saya mengaku membenarkan tesis (PSM/Sarjana/Doktor Falsafah) ini disimpan di Perpustakaan Universiti Teknikal Malaysia Melaka (UTeM) dengan syarat-syarat kegunaan seperti berikut: 1. Tesis adalah hak milik Universiti Teknikal Malaysia Melaka. 2. Perpustakaan Universiti Teknikal Malaysia Melaka dibenarkan membuat salinan untuk tujuan pengajian sahaja. 3. Perpustakaan dibenarkan membuat salinan tesis ini sebagai bahan pertukaran antara institusi pengajian tinggi. 4. **Sila tandakan ( ) SULIT TERHAD TIDAK TERHAD (Mengandungi maklumat yang berdarjah keselamatan atau kepentingan Malaysia yang termaktub di dalam AKTA RAHSIA RASMI 1972) (Mengandungi maklumat TERHAD yang telah ditentukan oleh organisasi/badan di mana penyelidikan dijalankan) Disahkan oleh: (TANDATANGAN PENULIS) Alamat Tetap: No 28, Jalan Kejayaan 44, Taman Universiti, 81300, skudai, Johor (TANDATANGAN PENYELIA) Cop Rasmi: Tarikh: 10 May 2010 Tarikh: * Tesis dimaksudkan sebagai tesis bagi Ijazah Doktor Falsafah dan Sarjana secara penyelidikan, atau disertasi bagi pengajian secara kerja kursus dan penyelidikan, atau Laporan Projek Sarjana Muda (PSM). ** Jika tesis ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi berkenaan dengan menyatakan sekali sebab dan tempoh tesis ini perlu dikelaskan sebagai SULIT atau TERHAD.

3 DECLARATION I hereby declare that this report entitled Development of interactive machining process design and machining time calculation is the result of my own research except as cited in the references. Signature : Author s name : Mohamad Izwan Bin Ishak Date : 09 April 2010

4 APPROVAL This report is submitted to the Faculty of Manufacturing Engineering of UTeM as a partial fulfillment of the requirements for the degree of Bachelor of Manufacturing Engineering (Manufacturing Management). The members of the supervisory committee are as follow: Ab Rahman bin Mahmood PSM Supervisor

5 ABSTRACT The title of this project is Development of interactive machining process design and machining time calculation. This project will discuss on the method to calculate the machining time and the cost involved in the machining process. The calculation of the machining time and cost is important in order to make a good planning for the production especially for a new product. The current method to calculate the machining time and cost is analyzed and will be compared with the proposed method. The excelbased software will be develop as a proposed method to calculate the machining time and cost. The software will include the selection of machining process, selection of tooling along with the other time element to calculate the machining time. After that, the cost involve in the machining process will be calculated from the time that result from the calculation with the addition of other cost like tool and material cost, indirect cost and etc. This software will help to reduce the workload for the one whom responsible to make the production planning. This software will be built in interactive way to make the software usage easier. i

6 ABSTRAK Tajuk projek ini ialah "Pembangunan rekabentuk proses permesinan interaktif dan pengkiraan masa permesinan". Projek ini akan membincangkan tentang kaedah untuk mengira kitaran masa permesinan dan kos yang terlibat dalam proses permesinan. Pengiraan kitaran masa permesinan dan kos adalah penting untuk membuat perancangan yang baik untuk pengeluaran terutamanya untuk produk baru. Kaedah yang sedag digunakan untuk mengira kitaran masa permesinan dan kos dianalisis dan akan dibandingkan dengan kaedah yang akan dicadangkan. Perisian berasaskan excel akan dihasilkan sebagai kaedah yang dicadangkan untuk mengira kitaran enjin masa dan kos. Perisian ynag akan dihasilkan akan merangkumi pemilihan proses permesinan, pemilihan mata alat bersama dengan elemen waktu lain untuk menghitung masa permesinan. Selepas itu kos permesinan akan dikira daripada masa yang kita dapatkan dari pengkiraan kitaran masa permesinan dengan tambahan kos lain seperti kos alat dan kos bahan, kos tidak langsung dan sebagainya. Perisian ini akan membantu untuk mengurangkan beban kerja bagi orang yang bertanggungjawab untuk membuat perancangan pengeluaran. Perisian ini akan dibina secara interaktif untuk membuat penggunaan perisian menjadi lebih mudah. ii

7 ACKNOWLEDGMENT In name of Allah S.W.T the most Merciful and the most Beneficent. It is with the deepest senses gratitude of the almighty that give me strength and ability to complete this project. First of all, I would like to take this opportunity to express my deepest gratitude to Mr. Hj. Abdul Rahman Bin Mahmood, the lecturer and supervisor for my project for the guidances while I am conducting my project and provide me with the material, ideas and suggestion in improving the contents of my project. Not forgotten also to all my friends and colleagues that had been a great help for me to complete my project properly and to Mr. Joizudin, Hicom-Engineering plant manager for giving me an opportunity to conduct my project at his company. iii

8 TABLE OF CONTENT Abstract Abstrak Acknowledgement Table of Content List of Tables List of Figures List Abbreviations i ii iii iv viii ix xi 1. INTRODUCTION Background Problem statement Objectives Scope and limitation 3 2. LITERATURE REVIEW CNC Lathe Machining Processes Facing Turning Parting Drilling Boring Grooving Threading Cutting Tools High speed steel Carbide Ceramic 9 iv

9 2.2 Machining time and cost calculation Machining time calculation Fixed time elements Piece related element Cost calculation and estimation Machining cost Material and tool cost Factory overhead Labor cost Machine amortization Microsoft Office Microsoft Office Excel Machining time and cost estimation system METHODOLOGY Identify project title Project details discussion Literature review Define the problem statement, objective, and scope Information collection Interviews Observation Methodology Software development Analyze current method to calculate the machining time and cost Sorting the relevant element and data input for the software Translate the relevant element and data to Microsoft Excel 2007 (Databases) Develop the software Testing and verification 27 v

10 3.7.6 Result comparison Completing report and submission DEVELOPMENT PROCESS Software Introduction Create the main and database sheet Create machining process sheet Turning process sheet Facing process sheet Drilling process sheet Parting process sheet Boring process sheet Grooving process sheet Threading process sheet Conditional formatting Sheet duplication Cost calculation sheet Change background colour and add hyperlink Data and formulation protection development RESULT AND ANALYSIS 5.1 Main menu worksheet Machining process worksheet Cost calculation worksheet Testing and verification First test (first example) Second test (second example) Questionnaire and Comparison analysis CONCLUSION AND RECOMMENDATION Conclusion Recommendations for future studies 64 vi

11 REFERENCES 65 APPENDICES A Gantt charts (PSM1 and PSM2) B Questionnaire C Example of answered questionnaire vii

12 LIST OF TABLES 4.1 No of sheet Databases cell command Turning cell command Facing cell command Drilling cell command Parting cell command Threading cell command Questionnaire average score Comparison between conventional method and software 62 viii

13 LIST OF FIGURES 2.1 Depth of cut and feed illustrated for turning operation Flowchart of the project Flowchart for development of the software Main sheet illustrations Combo box properties and hidden cell Hidden process design table Hidden table for processes machining time, process no and tool used Databases sheet Turning sheet Combo box properties and turning sheet hidden cell Facing process sheets Drilling operation sheet Drilling hidden cells Parting process sheet Boring operation sheet Grooving process sheet Threading process sheet Threading process sheet hidden cell Combo box for threading process Conditional formatting Cost calculation sheet Background colour change Add hyperlinks to system Cell lock and sheet protection 47 ix

14 5.1 Main menu worksheet Example of machining process sheet (Turning) Cost calculation worksheet Stock dimension (Creese, Robert C,1992) Process design table First cut parameter Process design table change First two pass process parameter Last two pass parameter Machining time result example 2 illustration (M. Adithan, 2007) Process design for example First process parameter Second process parameters Threading process parameters Software machining time result 59 x

15 LIST ABBREVIATIONS CNC - Computer numerical control Dia - Diameter NC - Numerical control HSS - High speed steel Rec - Recommended Rev. - Revolution mm - millimeters No. - numbers xi

16 CHAPTER 1 INTRODUCTION Chapter 1 will give a brief explanation about this project, starting with the background of the project title, Development of interactive machining process design and machining time calculation. This chapter will also discuss about the problem statement, the objectives and the scope and limitation for this project. 1.1 Background Nowadays, metal machining had become one of the important processes in manufacturing field. As it become important, the company that use metal machining processes need to make a production plan in order determine the acquisition, utilization and allocation of production resources to satisfy customer requirements in the most efficient and effective way. The examples of the important matters for the production planning are the machining time and the machining cost. Machining cost estimation is important and critical in manufacturing industries. There are major differences between what Western and Japanese manufacturing executives expect from cost information and how they utilize it. A manager in Europe or the United States has been known generally to use cost information to make decisions about pricing and investments, while a Japanese manager expects to use cost information to control costs (Tanaka, T. 1993). From the need to calculate the machining cost, there come the machining time calculation as with the machining time and cost per unit time for the processes, the machining cost can be estimated. Machining time and cost can be estimated completely 1

17 after a machining process plan is built. In machining processes, machines, processes, cutting tools and operation sequences are needed to make a process plan. There are many method can be used to calculate the machining time and cost before the production of the certain product started. Normally people calculate the machining time manually and referring to the standard, handbook, and machine manual before starting the production. This project will be made base on the purpose to make the work to calculate the machining time and cost easier for the production planning. 1.2 Problem statement Machining time and cost calculation for machining process using conventional way is a difficult method to determine the machining time and cost and can be considered as a time consuming. Nowadays, the machining time and cost is calculated using conventional way and sometimes the machining time and cost are estimated based on the experience and not calculated properly. The problems to calculate the machining time and cost using conventional method are; (1) Time consuming. (2) There are only few people know the method of calculating the machining time and machining cost that result to the estimation of the machining time and machining cost that are not so accurate. (3) Since calculating the machining time and machining cost require a lot of reference such as standard, manual, and handbook, it makes this work very troublesome and tedious. The purpose of this research and development is to introduce user friendly software using interactive way of calculating the machining time and machining cost. In order to solve the problem, this project is to develop software to calculate the machining time and cost of machining process so that the conventional method can be replaced by this software and ultimately make the work easier. 2

18 1.3 Objectives Based on the title Development of interactive machining process design and machining time calculation, the objectives to be achieved at the end of this project are as below; (1) To study the conventional method used to calculate machining time and cost (2) To develop a user friendly excel-based software using interactive way to calculate the machining time and machining cost. (3) To compare between the conventional method of calculating the machining time and cost with the software made. 1.4 Scope and limitation This project will develop excel-based software to calculate the machining time and machining cost and the calculation is only limited to lathe machining only. For the machining process selection, this software will only be limited to facing, turning, drilling, parting, grooving, boring and threading. The material that can be chosen using this software will be limited to low carbon, medium carbon, high carbon, aluminium casting and iron casting. For the tool selection, the tool will be limited to high speed steel, carbide and ceramic. The other metal machining process, material and tools will not be included in this software thus will not be covered in this project. 3

19 CHAPTER 2 LITERATURE REVIEW This chapter will explained about all the elements used for this report. First explanation will come to the machines, processes, cutting tools and operation sequences for lathe machine in order to know the element used to calculate the machining time and cost. After that, the conventional method to calculate the machining time and cost is explained. The computerized system is also explained in this chapter. 2.1 CNC Lathe Machining Lathe is one of the most versatile and one of the machine tools that have been widely used by people all over the world. Lathe machine is commonly known as the mother of all other machine tool. The main function of a lathe is to remove material from a work piece to produce the required shape and size. The work piece is firmly held in the chuck or in between centers on the lathe machine and then turn it against a single point cutting tool which wi1l remove material from the work piece in the form of chips. (Singh, R., 2006). The engine lathe, one of the most productive machine tools, has always been an efficient means of producing round parts (S. Krar, A. Gill, 1999). Around 1950s, servomechanisms were applied to lathe machine as the lathe machine can be controlled together with other machine tools via numerical control (NC). It is often that the lathe machine was coupled with the computers in order to yield the computerized numerical control (CNC). From year 1970 onwards, new design of machining tools had been 4

20 introduced into machining industry that brought along an effect of greatly reducing the times for tool positioning and movements between cuts. These new CNC design had been designed base directly to the development of numerically controlled (NC) machine tools from 1950s. In CNC machining tools, all the motions are mechanically separated and each different motion are driven by their own motor and coordinated electronically that allow more complicated feed motion can be done. As year 1970 come, the CNC lathe machine has more precise numerical control of feed motion, along with reduction of set-up time than can approximately halving the machine tools non-productive cycle times. In around 1980s, the reduction of non-productive cycle time for lathe machine had becoming more intense as the spread throughout all manufacturing industries of new types of machine tools that have become called turning centers. Nowadays, the manufacturing industries has been equipped with either manually controlled or CNC lathes for their production. The reason why CNC lathe machine had been used widely in manufacturing machining industry is because of the versatility that is the automatic tool changer. The automatic tool changer of lathe machine can change the tools between different machining operations without any user intervention. With this key of versatility, several machining operations can be executed in a single work piece setup. CNC lathe if classified according the axis of rotation can be divided into horizontal CNC lathe and vertical CNC lathe. For this study, it will focus on horizontal CNC lathe however this software is also applicable to the vertical CNC lathe Processes There are plenty of processes that can be done on lathe machine and the processes are facing, turning, drilling, parting, threading, boring and etc. For all the processes, there are some general rules to follow regarding the sequence of machining operation in order to do more than one processes to one product. The details for all the processes will be explained by following the sequence. 5

21 Facing Facing is the process of removing metal from the end of a work piece to produce a flat surface. Most often, the work piece is cylindrical, but using a 4-jaw chuck you can face rectangular or odd-shaped work to form cubes and other non-cylindrical shapes. (Hoose, F. J., 2000) Turning Turning is the removal of metal from the outer diameter of a rotating cylindrical work piece. Turning is used to reduce the diameter of the work piece, usually to a specified dimension, and to produce a smooth finish on the metal. Often the work piece will be turned so that adjacent sections have different diameters (Hoose, F. J., 2000) Parting Parting uses a blade-like cutting tool plunged directly into the work piece to cut off the work piece at a specific length. It is normally used to remove the finished end of a work piece from the bar stock that is clamped in the chuck. Other uses include things such as cutting the head off a bolt (Hoose, F. J., 2000) Drilling Drilling is the process to drill a hole in an object. A lathe can be used in drilling, only it is more difficult to support the work when it is bulky or heavy (Perrigo, O. E, 1916) 6

22 Boring Boring is a cutting operation that uses a single-point cutting tool to produce conical and cylindrical surfaces by enlarging an existing opening in a work piece. The cutting tool moves parallel to the axis of rotation (Todd, R. H. et al., 1994) Grooving Groove cutting on CNC lathes is a multi step machining operation. The term grooving usually applies to a process of forming a narrow cavity of a certain depth, on a cylinder, cone, or a face of the part (Smid P., 2003) Threading Threading operations actually involves cutting a helical groove of definite shape or angle, with a uniform advancement for each revolution, either on the surface of a round piece of material, or inside cylindrical hole (Miller R. and Miller M. R., 2004) Cutting Tools The selection of proper tooling for the process that wants to be made is important in order to make sure the production is successful. Normally the selection of tools to produce a specific work piece is a responsibility of tool engineer, machining process planner or programmer in case of the NC lathes. It is essential for the person responsible for tools selection to have a clear understand about the process and the material used. 7

23 High speed steel The advantages of High Speed Steel (HSS) Tool (1) HSS costs less than carbide or ceramic tooling. (2) HSS is less brittle and not as likely to break during interrupted cuts. (3) The tool can be re-sharpened easily. Disadvantages of High Speed Steel Tool (1) HSS does not hold up as well as carbide or ceramic at the high temperatures generated during machining. (2) HSS does not cut hard materials well Carbide Advantages of Carbide (1) Carbide holds up well at elevated temperatures. (2) Carbide can cut hard materials well. (3) Solid carbide tools absorb work piece vibration and reduce the amount of chatter generated during machining. (4) When inserted cutters are used, the inserts can be easily changed or indexed, rather than replacing the whole tool. Disadvantages of Carbide (1) Carbide costs more than high speed steel. (2) Carbide is more brittle than HSS and has a tendency to chip during interrupted cuts. (3) Carbide is harder to re-sharpen and requires diamond grinding wheels 8

24 Ceramic Advantages of ceramic tooling (1) Ceramic is sometimes less expensive than carbide when used in insert tooling (2) Ceramic will cut harder materials at a faster rate and has superior heat hardness. Disadvantages of ceramic tooling (1) Ceramic is more brittle than HSS or carbide (2) Ceramic must run within its given surface speed parameters. If run too slowly, the insert will break down quickly. The microstructures of the material give a tool its required bulk hardness and toughness may not be the best to give the rake and clearance surfaces the best wear resistance. Nowadays, the solution is to use coated tools their bulk optimized to resist failure and their surfaces coated to resist wear (Child, T. et al, 2000). Coatings should be harder than the coated material themselves, in order to give benefit in resisting abrasive wear, must be more inert to resist chemical wear, and must adhere well to the substrate. 2.2 Machining time and cost calculation Machining time and cost are important element need to be known in order to make a good production plan. Cost and time estimates are generated for small surface units called primitives using approximated tool paths and process parameters for available factory resources (Roberts, 2000). Cost estimation is one of the important things in the production planning as company can control their production by using the target costing. In order to make the cost estimation, a complete process plan is needed and from there the machining time of the processes can be calculated. The calculation of the machining time for the product or processes is the initial step in determining the machining cost. 9