CHAPTER 1 INTRODUCTION TO CNC 1
Transcript of CHAPTER 1 INTRODUCTION TO CNC 1
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