Introduction to Computer Numerical Control (CNC)

by Valentino, James V.; Goldenberg, Ed; Predator Inc, AAA

• ISBN13: 9780130944245
• ISBN10: 0130944246
• Edition: 3rd
• Format: Hardcover w/Disk
• Copyright: 2008-01-01
• Publisher: Pearson College Div

Summary

Provides basic training in an important area of modern manufacturing, computer numerical control (CNC). Designed to gradually develop the most fundamental concepts in CNC technology using language that is easy for beginners to understand. Previous edition c2000.

Table of Contents

Introduction to Computer Numerical Control Manufacturing	1	(12)
Chapter Objectives	1	(1)
Introduction	1	(1)
Numerical Control Definition, Its Concepts and Advantages	1	(1)
Definition of Computer Numerical Control and its Components	2	(2)
Advantages of CNC Compared with NC	4	(1)
Special Requirements for Utilizing CNC	4	(1)
Financial Rewards of CNC Investment	5	(1)
CNC Machining Centers and Turning Centers	6	(2)
Other Types of CNC Equipment	8	(1)
CNC Input and Storage Media	8	(3)
Chapter Summary	11	(2)
Review Exercises	11	(2)
Modern Machine Tool Controls	13	(13)
Chapter Objective	13	(1)
Introduction	13	(1)
Different Types of System Control	13	(3)
Loop Systems for Controlling Tool Movement	16	(2)
Establishing Locations via Cartesian Coordinates	18	(1)
CNC Machine Axes of Motion	19	(3)
Types of Tool Positioning Modes	22	(1)
Units Used for Positioning Coordinates	23	(1)
Chapter Summary	24	(2)
Review Exercises	24	(2)
Tooling for Hole and Milling Operations	26	(22)
Chapter Objectives	26	(1)
Introduction	26	(1)
Tooling for Drilling Operations	26	(4)
Carbide Insert Technology	30	(2)
Tooling for Hole Operations that Follow Drilling	32	(3)
Tool Speeds and Feeds for Hole Operations	35	(2)
Tooling for Profile Milling and Facing Operations	37	(4)
Coated Tooling	41	(1)
Tool Speeds and Feeds for Milling Operations	41	(4)
Feed Directions for Milling Operations	45	(1)
Cutting Fluids for CNC Operations	45	(1)
Chapter Summary	46	(2)
Review Exercises	46	(2)
Exploring Features of CNC Machining Centers	48	(14)
Chapter Objectives	48	(1)
Introduction	48	(1)
Background on CNC Machining Centers	48	(2)
Tooling Systems Used with Automatic Tool Changers	50	(3)
Methods of Securing Tools in Tool Holders	53	(1)
Methods of Securing Tooling Systems to the CNC Spindle	54	(1)
Automatic Tool Changer Systems	55	(2)
Pallet Loading Systems	57	(3)
Chapter Summary	60	(2)
Review Exercises	61	(1)
Review of Basic Blueprint Reading for CNC Programmers	62	(72)
Chapter Objective	62	(1)
Introducion	62	(1)
Sheet Sizes	62	(1)
Drawing Formats	63	(6)
Interpreting Lines in Drawings	69	(4)
Projection Conventions Used in Drawings	73	(2)
Visualizing 3D Objects from 2D Othographic Views	75	(1)
Auxiliary Views	75	(1)
Sectional Views	75	(1)
Reading Dimensions	75	(23)
Reading Threads and Thread Notes	98	(10)
Reading Surface Finish Symbols and Notes	108	(1)
Reading Material Specifications	109	(13)
Understanding Heat Treatment Notes	122	(2)
Interpreting Surface Coating Notes	124	(7)
Chapter Summary	131	(3)
Review Exercises	131	(1)
Bibliography	132	(2)
Review of Basic Geometric Dimensioning and Tolerancing for CNC Programmers	134	(17)
Chapter Objectives	134	(1)
Introduction	134	(1)
GDT Terminology	135	(2)
Part Form Controls	137	(4)
Datums	141	(1)
Part Profile Controls	142	(1)
Part Location, Orientation, and Runout Controls	142	(7)
Chapter Summary	149	(2)
Review Exercises	149	(1)
Bibliography	150	(1)
Mathematics for CNC Programming	151	(11)
Chapter Objectives	151	(1)
Introduction	151	(1)
Determining Sides of Right Triangles	151	(1)
Useful Angle Concepts	152	(4)
Determining Angles of Right Triangles	156	(1)
Oblique Triangles	157	(1)
Chapter Summary	158	(4)
Review Exercises	158	(4)
An Overview of CNC Shop Activities	162	(12)
Chapter Objectives	162	(1)
Introduction	162	(1)
Essential CNC Shop Activities	162	(1)
Part Drawing Study	162	(3)
Methodizing of Operations	165	(1)
Deciding on a CNC Machine	165	(1)
Methods of Holding the Part During Machining	166	(1)
Machining Determination	167	(1)
Cutting Conditions	167	(1)
Writing a Part Programming Manuscript	167	(1)
Inputting Programs to the MCU	167	(2)
Setup and Machining Documentation	169	(1)
Setup Procedure	170	(2)
Debugging and Verifying the Program	172	(1)
Part Production	172	(1)
Chapter Summary	172	(2)
Review Exercises	173	(1)
Word Address Programming	174	(12)
Chapter Objectives	174	(1)
Introduction	174	(1)
Programming Language Format	174	(1)
Programming Language Terminology	175	(2)
Arrangement of Addresses in a Block	177	(1)
Program and Sequence Numbers (O, N Codes)	177	(1)
Preparatory Functions (G Codes)	178	(2)
Dimension Words (X, Y, Z ... Codes)	180	(1)
Feed Rate (F Code)	181	(1)
Spindle Speed (S Code)	181	(1)
Miscellaneous Machine Functions (M Codes)	182	(1)
Automatic Tool Changing (M06 Code)	182	(1)
Tool Length Offset and Cutter Radius Compensation (H, D Codes)	183	(1)
Comments	183	(1)
Chapter Summary	184	(2)
Review Exercises	184	(2)
Programming Hole Operations	186	(19)
Chapter Objectives	186	(1)
Introduction	186	(1)
Fixed or Canned Cycles	186	(1)
Hole Operation Commands	187	(6)
Writing a Hole Operation Program	193	(7)
Chapter Summary	200	(5)
Review Exercises	200	(5)
Programming Linear Profiles	205	(27)
Chapter Objectives	205	(1)
Introduction	205	(1)
Linear Interpolation Commands	205	(1)
Writing a Linear Profiling Program	205	(6)
Determining Cutter Offsets for Inclined Line Profiles	211	(15)
Chapter Summary	226	(6)
Review Exercises	226	(6)
Programming Circular Profiles	232	(32)
Chapter Objectives	232	(1)
Introduction	232	(1)
Specifying the Plane for Circular Arc Interpolation	232	(1)
Circular Interpolation Commands	232	(6)
Circular Interpolation via Direct Radius Specification	238	(2)
Profiling Arcs at Constant Feed Rate	240	(1)
Determining Cutter Offsets for Line-Arc Profiles	241	(13)
Chapter Summary	254	(10)
Review Exercises	254	(10)
Programming with Cutter Diameter Compensation	264	(23)
Chapter Objectives	264	(1)
Introduction	264	(1)
Cutter Diameter Compensation	264	(2)
Advantages of Using Cutter Diameter Compensation	266	(1)
Some Restrictions with Cutter Diameter Compensation	266	(2)
Cutter Diameter Compensation Commands	268	(7)
Cutter Diameter Compensation with Z-Axis Movement	275	(1)
Cutter Diameter Compensation Interruptions	275	(7)
Chapter Summary	282	(5)
Review Exercises	282	(5)
Programming With Subprograms	287	(29)
Chapter Objectives	287	(1)
Introduction	287	(1)
Subprogram Concept	287	(1)
Fanuc Commands for Calling a Subprogram and Returning to the Main Program	288	(3)
Additional Subprogram Control Features	291	(1)
General Rules for Subprogramming	292	(17)
Chapter Summary	309	(7)
Review Exercises	310	(6)
Introduction to the CNC Lathe	316	(15)
Chapter Objectives	316	(1)
Introduction	316	(1)
Components of Modern CNC Lathes	316	(3)
CNC Lathe Axes of Motion	319	(1)
Basic Lathe Operations	320	(2)
Tooling for CNC Lathe Operations	322	(4)
Tool Speeds and Feeds for Lathe Operations	326	(1)
Feed Directions and Rake Angles for Lathe Operations	327	(2)
Chapter Summary	329	(2)
Review Exercises	329	(2)
Fundamental Concepts of CNC Lathe Programming	331	(26)
Chapter Objectives	331	(1)
Introduction	331	(1)
Establishing Locations via Cartesian Coordinates (CNC Lathes)	332	(1)
Types of Tool Positioning Modes (CNC Lathes)	333	(2)
Reference Point, Machining Origin, and Program Origin	335	(1)
Setup Procdures for CNC Lathes	336	(2)
Important Preparatory Functions (G Codes) for Lathes	338	(1)
Important Miscellaneous Functions (M Codes) for Lathes	338	(1)
``Zero Offset'' Command	339	(1)
Feed Rate (F Code)	339	(1)
Spindle Speed (S Code)	340	(1)
Spindle Speed with Constant Surface Speed Control	341	(1)
Spindle Speed with Clamp Speed and Constant Surface Speed Controls	341	(2)
Automatic Tool Changing	343	(1)
Linear Interpolation Commands (CNC Lathes)	344	(1)
Determining Cutter Offsets for CNC Lathes Operations	344	(3)
Circular Interpolation Commands (CNC Lathes)	347	(3)
Grooving Commands	350	(1)
Return to Reference Point Command	351	(1)
Chapter Summary	352	(5)
Review Exercises	352	(5)
Techniques and Fixed Cycles for CNC Lathe Programming	357	(49)
Chapter Objectives	357	(1)
Introduction	357	(1)
Tool Edge Programming	357	(1)
Tool Nose Radius Compensation Programming	358	(1)
Setting Up Tool Nose Radius Compensation	359	(2)
Some Restrictions with Tool Nose Radius Compensation	361	(1)
Tool Nose Radius Compensation Commands	361	(6)
Turning and Boring Cycle: G90	367	(3)
Facing Cycle: G94	370	(2)
Multiple Repetitive Cycles: G70 to G75	372	(1)
Stock Removal in Turning and Boring Cycle: G71	372	(2)
Finish Turning and Boring Cycle: G70	374	(6)
Peck Drilling and Face Grooving Cycle: G74	380	(5)
Peck Cutoff and Grooving Cycle: G75	385	(4)
Thread Cutting on CNC Lathes and Turning Centers	389	(1)
Single-Pass Threading Cycle: G32	390	(3)
Multiple-Pass Threading Cycle: G92	393	(2)
Multiple Repetitive Threading Cycle: G76	395	(2)
Chapter Summary	397	(9)
Review Exercises	397	(9)
Modern Computer-Aided Part Programming	406	(29)
Chapter Objectives	406	(1)
Introduction	406	(1)
Modern Developments in the Process of CNC Programming	406	(1)
Using and Off-Line Computer to Write and Store Part Programs	407	(1)
An Introduction to Computer-Aided Programming Languages	407	(1)
Elements of the APT Programming Language	408	(4)
Writing a Complete Program in APT	412	(4)
An Introduction to CAD/CAM Technology	416	(1)
The Elements Comprising CAD	416	(3)
The Elements Comprising CAM	419	(3)
Creating a Complete Part Program Using Mastercam CNC Software	422	(10)
Chapter Summary	432	(3)
Review Exercises	433	(2)
Elements of the Computer-Controlled Factory	435	(10)
Chapter Objectives	435	(1)
Introduction	435	(1)
Computer-Integrated Manufacturing	435	(2)
Operational Strategies Within CIM	437	(1)
Flexible Manufacturing Systems	437	(2)
Important Elements of Flexible Manufacturing Systems	439	(1)
Flexible Manufacturing Cells	440	(1)
Important Elements of Flexible Manufacturing Cells	440	(2)
Networking Within CIM	442	(1)
Need for Training	443	(1)
Chapter Summary	444	(1)
Review Exercises	444	(1)
Verifying Part Programs	445	(68)
Chapter Objectives	445	(1)
Introduction	445	(1)
Predator Simulation Software	445	(1)
System Requirements	446	(1)
Conventions Used in This Chapter	446	(1)
Installation	447	(1)
An Overview of Writing and Verifying Programs	447	(2)
Types of Files Created by Predator	449	(1)
Running an Old Simulation Job Stored on Disk	450	(12)
Running an Old Simulation Job Stored on Disk	462	(4)
Running an Old Simulation Job from C Drive	466	(2)
Preparing a Disk for Storing New Simulation Jobs	468	(2)
Writing a Word Address CNC Program Via the CNC Editor	470	(2)
Using Edit Commands	472	(2)
Using Insert Commands	474	(1)
Using File Commands	475	(3)
Starting the Virtual CNC and Creating Simulation Files	478	(5)
Entering Data into the Setup File on C Drive	483	(14)
Directing the Virtual CNC to Process a Job	497	(5)
Using the Virtual CNC to Inspect a Machined Part	502	(4)
Entering the CNC Editor from Virtual CNC	506	(1)
Creating a New Tool in the Tool Library	507	(3)
Simulating Programs with Cutter Diameter Compensation	510	(3)
Appendix A	513	(2)
Important Safety Precautions	513	(2)
Appendix B	515	(6)
Summary of G Codes for Milling Operations (Fanuc Controllers)	515	(2)
Summary of G Codes for Turning Operations (Fanuc Controllers)	517	(1)
Summary of M Codes for Milling and Turning Operations (Fanuc Controllers)	518	(1)
Summary of Codes for Auxiliary Functions (Fanuc Controllers)	519	(2)
Appendix C	521	(4)
Recommended Speeds and Feeds for Drilling	521	(1)
Recommended Speeds and Feeds for Milling	522	(1)
Recommended Speeds and Feeds for Turning	523	(2)
Appendix D	525	(2)
Summary of Important Machining Formulas	525	(2)
Glossary	527	(8)
Index	535

Excerpts

One of the greatest challenges facing the United States today is in the area of manufacturing. To a large extent the computer has revolutionized this technology. It has virtually transformed the process of product design, analysis, and manufacture. Industries are finding that the new manufacturing technology demands well-trained personnel. Education is now being viewed as a continuous and long-term investment. The third edition ofIntroduction to Computer Numerical Control (CNC)has been expanded and improved. The blueprint reading material has been separated as follows: Chapter 5--Review of Basic Blueprint Reading for CNC Programmersand Chapter 6--Review of Basic Geometric Dimensioning and Tolerancing for CNC Programmers. Chapter 18 now includes a presentation on creating and simulating a complete part program usingMastercamCNC software. The third edition introduces the use of CNC software for writing, verifying, and simulating the milling word address programs in this text. To this end, a new Chapter 20, titledVerifying Part Programs,has been added. Included with this edition is a bound CD-ROM disk containing powerful, industrial quality CNC verification and simulation software. The software displays real-time solid model animation of the machining that results from a part program. Additionally, it has an inspection mode that enables students to section as well as verify the dimensions of the machined part. The milling part programs in the text have been edited so they will work properly with the verification and simulation software. Each chapter begins with a brief listing of objectives and ends with a chapter summary. Illustrations and photographs are used liberally throughout to reinforce pictorially what is being discussed. Students are frequently directed to boxed-in key terms and concepts. Flowcharts are used to teach CNC process planning and program planning. The important topic of job setup is discussed in the many solved programming examples. Fundamental word address (G and M code) programming is stressed. Industrial standard practices and terms are emphasized in the solved programming examples. Needless cross-referencing has been eliminated. Each program is listed with all explanations appearing on the same page. Pattern recognition is emphasized. The student is taught to recognize a certain group of programming commands as a programming pattern. For example, pattern A commands start up the CNC machine, whereas pattern B commands cause a tool change to take place. An excellent assortment of review exercises is provided at the end of each chapter. These exercises supply the student such important information as the operation to be performed, tooling, tool speed, tool feed, and job setup data. The industry standard Fanuc controller is emphasized throughout the text. Important mathematical principles are reviewed before programming is presented. A special chapter on right-triangle trigonometry provides the student with the critical mathematical information needed to understand programming. The student is exposed to the big picture of CNC shop activities. A special chapter explains the most important operations to be carried out in manufacturing a part. Appendixes contain information useful to the CNC student. They include a list of important safety precautions; summaries of G and M codes for milling and turning operations; recommended speeds and feeds for different materials with respect to drilling, milling, and turning operations; and important and easy-to-use machining formulas. A comprehensive glossary of key CNC terms is provided at the end of the book. Verification and simulation software enables students to visualize the effects of a written part program. Introduction to Computer Numerical Co