CHAPTER 1 INTRODUCTION TO CNC 1

Chapter ObjectivesIntroduction 2

The Evolution of NC 2

Microcomputer Technology 7

Computer Basics 9

NC Applications 9

Milling 9

Turning 9

Wire EDM 9

Laser, Flame, and Plasma 1 1

Punching and Nibbling 1 1

Robots and CNC 1 1

Controller Standards 1 2

CNC Controllers 14

ElA and ISO Standards 1 4

Conversational (Nonstandard) 1 5

The CNC Process 1 5

Flow of CNC Processing 1 6

Flow of Computer-Aided CNC Processing 1 6

Quality Control 1 6

Lab Exercises 1 7

IX

x CONTENTS

CHAPTER 2 CNC FUNDAMENTALS

AND VOCABULARY 1 9

Chapter Objectives 1 9

Axis and Motion Nomenclature 21

The Right-Hand Rule of Coordinates 21

CNC Milling Fundamentals 23

The Cartesian Graph for CNC Milling 2 3

Absolute Coordinates for Milling 24

Incremental Coordinates for Milling 26

Exercises 26

CNC Turning Fundamentals 27

Diameter Versus Radius Programming 2 9

Absolute Coordinates for Turning 3 O

Incremental Coordinates for Turning 3 1

Exercises 32

Lab Exercises 3 3

CHAPTER 3 PROGRAMMING CONCEPTS 35

Chapter Objectives 35

lntroduction 36

Flow of CNC Processing 36

Preparing a Program 36

CNC Codes 37

Three Major Phases of a CNC Program 3 B

U sing a Programming Sheet 4 O

Block Format 40

Preparing to Program 4 1

Develop an Order of Operations 4 1

Do All the Necessary Math and Completea Coordinate Sheet 4 1

Choose Your Tooling and Calculate Speedsand Feedrates 42

Program Zero 43

Tool Motion 44

Using Canned Cycles 44

Tooling 45

Drilling 46

Milling 46

Punching and Nibbling 46

Turning 47

CONTENTS XI

Feedrates and Spindle Speeds 48

Cutting Fluids 49

Lab Exercises 5 O

CHAPTER 4 INTERACTIVE SIMULATION

SOFTWARE 51

Chapter Objectives 5 1

Installation and Setup 52

Installing and Running the Workshop 52

Default Configuration 54

The User Interface 55

Accessing Menu Options 56

Menus 57

File 57

Setup 60

Offset Registers 6 1

Options 62

Workpiece 63

View 64

Simulate 66

Help 68

Getting Started 6 B

Loading and Running a Sample CNC File 68

Editing an Existing Program 69

Writing and Executing Your Own CNCProgram 69

Saving a New CNC File 70

Printing the Current CNC Program File 70

Exiting the Simulator 7o

CHAPTER 5 CNC MILLING 71

Chapter Objectives 7 1

Letter Address Listing 72

G-Codes 74

GOO Positioning in Rapid 74

GOl Linear Interpolation 76

G02 Circular Interpolation (CW) 78

G03 Circular Interpolation (CCW) 79

G04 Dwell 81

G17 XY Plane 82

G18 XZ Plane 83

XII CONTENTS

G19 YZ Plane a4G20/G70 Imperial Inch Units a 5

G2l/G71 Metric, or si Units a 6

G28 Automatic Return to Reference Point a 7

G29 Automatic Return from Reference Point aaG40 Cutter Compensation Cancel a9G4l Cutter Compensation Left 90

G42 Cutter Compensation Right 93

G43 ToolLength Compensation (Plus)G44 Tool Length Compensation (Minus)G49 Tool Length Compensation CancelG54-G59 Workpiece Coordinate SystemsG73 High-Speed Deep Hole Drilling CycleG80 Cancel Canned Cycles 1o oG81 Drilling Cycle 101

G82 Spot Drilling Cycle 102

G83 Deep Hole Drilling Cycle 104

G90 Absolute Positioning 105

G9l Incremental Positioning 106

G92 Reposition Origin Point 107

G98 Set Initial Plane Rapid Default 1 O aG99 Set Rapid to Retract Plane 1 Oa

M-Codes 1 09

MOOProgram Stop 109

MOl Optional Program StopM02 Program End 1 1 1

M03 Spindle on Clockwise 1 1 2

M04 Spindle on CounterclockwiseM05 Spindle Stop 1 1 3

M06 Tool Change 1 1 4

M07/M08 Coolant On 1 1 5

M09 Coolant Off 1 1 5

Ml0 Clamps On 1 1 6

Mll Clamps Off 1 1 7

M30 Program End, Reset to StartM98 Call Subprogram 1 1 aM99 Return from SubprogramBlock Skip 121

Comments 1 22

95

9697

9a

99

1 1 O

1 1 2

1 1 a

120

CONTENTS XIII

Step-by-Step Milling Examples 123

Lab Exercises 1 5 9

CHAPTER 6 TURNING 161

Chapter Objectives 1 6 1

Letter Address Listing 1 6 2

G-Codes 164GOOPositioning in Rapid 165

GOl Linear Interpolation 166

G02 Circular Interpolation (CW) 167

G03 Circular Interpolation (CCW) 169

G04 Dwell 1 7 O

G20 Inch Units 17 ,

G21 Metric Units 172

G28 Automatic Zero Return , 73G29 Return from Zero Return Position 173

G32 Simple Thread Cycle 175

G40 Tool Nose Radius (TNR) Compensation Cancel , 75

G41 Tool Nose Radius Compensation Left 176

G42 Tool Nose Radius Compensation Right 1 77

G50 Coordinate System Setting ar ProgrammingAbsolute Zero 179

G54-G59 Work Coordinate Systems 1 8 O

G70 Finishing Cycle 180

G71 Rough Turning Cycle 181

G72 Rough Facing Cycle 183

G74 Peck Drilling Cycle 184

G75 Grooving Cycle , 86

G76 Threading Cycle , 87

G90 Absolute Positioning 1 88

G91 Incremental Positioning 1 88

G96 Constant Surface Speed Setting 189

G97 Constant Spindle Speed 1 9 O

G98 Linear Feedrate per Time 1 9 1

G99 Feedrate per Revolution , 92

M-Codes , 9 3

MOOProgram Stop 1 9 3

MOI Optional Program Stop 194

M02 Program End , 95

XIV CONTENTS

M03 Spindle on Clockwise 196

M04 Spindle on Counterclockwise 197

M05 Spindle Stop 1 97

M07 Coolant 1 On 1 98

M08 Coolant 2 On 1 99

M09 Coolant Off 2 O O

M30 End of Program, Reset to Start 2 O 1

Block Skip 2 O 1

Comments 2 O 3

Step-by-Step Turning Examples 2 03

Lab Exercises 237

CHAPTER 7 INTRODUCTION TO CAD/CAM 239

Chapter Objectives 23 9

The Basic CAD/CAM System 240

Computer-Aided Design 240

AutoCAD 242

Computer-Aided Manufacturing 243

EdgeCAM 245

lntroduction to EdgeCAM 247

Example of Creating Geometry in EdgeCAM 2 52

MasterCAM 276

Example of Creating Geometry in MasterCAM 277

The CAD/CAM System 2 9 7

Overall Benefits of CAD/CAM 2 9 B

Design 298

Drafting 29 8

Manufacturing 298

Management Control 299

Concurrent Engineering 299

Product Quality 299

Lab Exercises 3 O O

CHAPTER a WORKBOOK EXERCISES 301

Chapter ObjectivesWorkbook Exercises

301

302

Exercise 1: A Review 3 O 2

Exercise 2: Calculating Diametrical Coordinatesfor Turning 3 O4

CONTENTS xv

Exercise 3: Calculating Coordinates for Simple Drillingand Slotting 3 O4

Exercise 4: Lathe Profile Programming 305

Exercise 5: Drilling Bolt Holes 3 O6

Exercise 6: Circular Arc Moves 3O7

Exercise 7: Mill Profiling 3 O9

Exercise 8: Material Removal for Turning 31 O

Exercise 9: Material Removal for Milling 3 1 3

Advanced Exercises 3 1 5

Exercise 10 3 15

Exercise 11 3 1 B

APPENDIX A ANSWERS TO LAs EXERCISES 323

Chapter 1:Lab Exercises 323

Chapter 2: In-Text Exercises 324

Milling Exercises 324

Turning Exercises 324

Chapter 2: Lab Exercises 324

Chapter 3: Lab Exercises 325

Chapter 5: Lab Exercises 326

Chapter 6: Lab Exercises 326

Chapter 7: Lab Exercises 327

Chapter 8: Workbook Exercises 327

Workbook Exercise 1 327

Workbook Exercise 2 32 9

Workbook Exercise 3 32 9

Workbook Exercise 4 32 9

Workbook Exercise 5 330

Workbook Exercise 6 332

Workbook Exercise 7 334

Workbook Exercise 8 335

Workbook Exercise 9 336

Workbook Exercise 10 337

Workbook Exercise 11 342

APPENDIX B 345

Cutting Speeds and FeedratesFormulas 345

Feedrates (Inch) 345

345

XVI CONTENTS

Feedrates (Metric) 345

Milling Material Table (Inch Version) 346

Milling Material Table (Metric Version) 346

Lathe Material File (Inch Version) 347

Lathe Material File (Metric Version) 34 B

APPENDIX a 349

Blank Programming Sheets 350

Technical Support 361

GL....OSSSARY 363

INDEX 3"73