Wentworth
Institute of Technology
Basics of CNC programming /
Before the introduction of automatic machines and automation, industrial manufacturing of machines and their parts for the key industries were made though manually operated machines. Due to this, manufacturers could not make complex profiles or shapes with high accuracy. As a result, the production...
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| Format: | Electronic eBook |
| Language: | English |
| Published: |
Gistrup, Denmark :
River Publishers,
[2019]
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| Series: | River Publishers Series in Mathematical and Engineering Sciences Ser.
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| Subjects: | |
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Full text (WIT users only) |
Table of Contents:
- Preface xix
- Acknowledgement xxi
- List of Figures xxiii
- List of Abbreviations xliii 1 CNC Machine and Its Importance 1
- 1.1 History of CNC Machine 1
- 1.2 What is CNC? 2
- 1.3 Working of CNC Machine 3
- 1.4 Language of CNC Machine 3
- 1.5 Benefits: After Coming to the CNC Machine 3
- 1.6 Fast Change Over 4
- 1.7 What is the Importance of CNC Machine in the Modern World? 4
- 1.8 Advantages and Disadvantages of CNC Machine 4
- 1.8.1 Advantages 5
- 1.8.2 Some Most Important Advantages of CNC Machine 5
- 1.8.3 Disadvantages 6
- 1.9 Types of CNC Machines 7
- 1.10 Some Constructional Features of CNC Machine 7
- 1.11 Important Parts of CNC Machine 11
- 1.12 What Do You Mean By NC And CNC Machine? 12
- 1.13 Difference Between the NC Machine and CNC Machine 13
- 1.13.1 NC Machine 13
- 1.13.2 CNC Machine 13
- 1.14 What is CNC Control Software? 14
- 1.14.1 Some Popular CNC Control Software Names are Given Below 15
- References 15
- 2 Turning Process and Its Cutting Parameters 17
- 2.1 What is Turning?/What is Turning Operation? 17
- 2.2 What is Adjustable Cutting Factor in Turning Machine? 17
- 2.3 What is the Feed, Cutting Speed, Spindle Speed and Depth of Cut? 17
- 2.3.1 Spindle Speed 17
- 2.3.2 Feed 17
- 2.3.3 Cutting Speed 18
- 2.3.4 Depth of Cut 19
- 2.4 What are the Turning, Facing, Straight Turning, Step Turning, Drilling, Boring and Threading Operations? 19
- 2.4.1 Turning Operation 19
- 2.4.2 Important Tips 20
- 2.4.3 Facing Operation 20
- 2.4.4 Plain Turning/Straight Turning Operation 20
- 2.4.5 Step Turning Operation 22
- 2.4.6 Drilling 22
- 2.4.7 Taper Turning Operation 23
- 2.4.8 Boring Operation 23
- 2.4.9 Threading Operation 23
- 2.5 Why We Choose the CNC Machine for Manufacturing the Products? 24
- 2.6 What Should We Need for Manufacturing the Product in CNC Machine? 25
- References 25
- 3 Importance of Alphabets in CNC Programming 27
- 3.1 Alphabets, Which are Used in CNC Programming? 27
- 3.1.1 A Rotary axis around the X-axis (unit in degrees) 27.
- 6 (Straight Turning Program with Multiple Rough Cutting) 290 9.2.7 Program No. 7 (Step Turning Program) 292 9.2.8 Program No. 8 (Multi Step Turning Program) 294 9.2.9 Program No. 9 (Multiple Steps Turning Program) 296 9.2.10 Program No. 10 (Continuous Drilling Program) 298 9.2.11 Program No. 11 (Peck Drilling Program) 299 9.2.12 Program No. 12 (Peck Drilling Program with Deep Hole) 301 9.2.13 Program No. 13 (Chamfering Program) 303 9.2.14 Program No. 14 (Chamfering Program) 305 9.2.15 Program No. 15 (Chamfering Program with Rough Cut) 307 9.2.16 Program No. 16 (Corner Radius Program with Rough Cut and Counter Clock Wise Direction) 308 9.2.17 Program No. 17 (Corner Radius Program with Counter Clock Wise Direction) 310 9.2.18 Program No. 18 (Corner Radius Program in Clock Wise Direction) 311 9.2.19 Program No. 19 (Taper Turning Program) 313 9.2.20 Program No. 20 (Taper Turning Program with Rough Cut) 314 9.2.21 Program No. 21 (Taper Turning Program) 316 9.2.22 Program No. 22 (Threading Program) 317 9.2.23 Program No. 23 (Threading Program with Pitch 1.25) 319 9.2.24 Program No. 24 (Threading Program with Pitch 2.0) 321 9.3 Profile Turning 323 9.3.1 Program No. 25 (Profile Turning with Multi Tool Program) 323 9.3.2 Program No. 26 (Radius Profile Turning with Multi Tool Program) 326 9.3.3 Program No. 27 (Turning Profile Program) 330 9.3.4 Program No. 28 (Multi Tool Program for Profile Turning and Threading Operation) 332 9.3.5 Program No. 29 (CNC Programming for Oval Shape) 336 9.3.6 Program No. 30 (CNC Programming for Circular Clock Wise Direction) 338 9.3.7 Program No. 31 (CNC Programming for Big Arc Profile) 341 9.3.8 Program No. 32 (Profile Turning with Multi Cutting Tools) 343 9.4 How Will You Take Work Zero Offset G54? or Where You Will Take Z Zero (Z = 0) on the Work piece Surface? 347 9.5 Practice Drawings with Multiple Cutting Tools 349 9.5.1 Choose Correct Answers and Fill in the Blanks where from Program Lines are Missing in following CNC Programs 350 9.5.1.1 Figure 9.291 shows both the raw material and machining in one drawing 350 9.5.1.2 Figure 9.292 shows both the raw material and machining in one drawing 353 9.5.1.3 Figure 9.293 shows both the raw material and machining in one drawing 354 9.5.1.4 Figure 9.294 shows both the raw material and machining in one drawing 356 9.5.1.5 Figure 9.295 shows both the raw material and machining in one drawing 359 9.5.1.6 Figure 9.296 shows both the raw material and machining in one drawing 360 9.5.1.7 Figure 9.297 shows both the raw material and machining in one drawing 362 9.5.1.8 Figure 9.298 shows both the raw material and machining in one drawing 363 9.5.1.9 Figure 9.299 shows both the raw material and machining in one drawing 366 9.5.1.10 Figure 9.300 shows the raw material and machining drawing in one drawing 369 9.5.1.11 Figure 9.301 shows the raw material and machining drawing in one drawing 372 References 375 10 Cutting Insert (Bit) and Cutting Tool Holders Nomenclatures 377 10.1 What are Cutting Inserts? What are the Benefits of the Right Cutting Insert? 377 10.2 When We Select an Insert/Bit for Machining. We Should Keep Following Important Points in Our Mind 378 10.2.1 Characteristics of the Inserts (Figure 10.1) 378 10.3 What are Positive and Negative Inserts? Where and Which Type of Machining these are Used? 379 10.3.1 Negative Insert (Bit) 379 10.3.1.1 Advantages of negative inserts 380 10.3.1.2 Names of some negative inserts 381 10.3.2 Positive Insert 381 10.3.2.1 Advantages of positive inserts 382 10.3.2.2 Names of some positive inserts 382 10.4 Turning Tool Insert's Nomenclature 382 10.4.1 Insert Shape 383 10.4.2 Insert Clearance Angle/Insert Relief Angle 384 10.4.3 Insert Tolerance 384 10.4.4 Types of Inserts 384 10.4.5 Insert Cutting Edge Length 385 10.4.6 Insert Thickness 385 10.4.7 Insert Corner Radius 387 10.4.8 Insert Cutting Edge Condition 387 10.4.9 Insert Cutting Direction/Hand of Tool 387 10.4.10 Insert Chip Breaker 389 10.5 Turning Tool Holders (External Tool Holders): ISO Nomenclature 389 10.6 Boring Tool Holders Nomenclature: ISO Codes Key 390 10.7 What is Cutting Tool Entering Angle? 391 10.8 What is Boring Bar or Boring Tool? Where it is Used? 392 10.9 Different Types of Boring Tools (Internal Machining Tools) 392 10.10 Different Types of Turning Tools (External Machining Tools) 394 10.10.1 What are Right Hand and Left Hand Cutting Tools? 394 10.10.1.1 Right hand cutting tool 394 10.10.2 Left Hand Cutting Tool 395 10.10.3 Right Hand Cutting Tool Images 396 10.10.4 Left hand cutting tools images 397 10.11 Neutral Cutting Tools 398 10.11.1 What is Neutral Tool? Where it is Used? 398 References 399 11 Drawings and CNC Programs 401 11.1 Drawings for CNC Programming: Exercise 401 11.2 Write Your Own CNC Programs by using Following Drawings and Match with Given Following CNC Programs 407 11.2.1 Following Drawings are Programmed with Finishing Cut Program 407 11.3 Important Tips Before and After Machining 414 11.3.1 Cutting Fluid (Coolant) 414 11.3.2 Safety Precautions 415 11.4 Interview Questions 416 11.4.1 The Following Questions Can Be Asked in Interview 416 11.5 Answers Keys 417 11.6 Formulas of Cutting Speed, Spindle Speed, Feed, Feed Per Tooth and Cutting Time 430 11.6.1 Cutting Time 431 11.7
- Important Notes 431
- References 431
- Index 433
- About the Authors 437.
- 3.1.2 B Rotary axis around Y-axis (unit in degrees) 27
- 3.1.3 C Rotary axis around Z-axis (unit in degrees) 27
- 3.1.4 D Depth of cut 27
- 3.1.4.1 Formula to Find Out Unknown Diameter on Turning Machine 27
- 3.1.5 E For accuracy control during machining operation/engraving feed rate or contouring accuracy 28
- 3.1.6 F Feed is like a cutting force of the tool. This is applied during material removing 28
- 3.1.7 G Preparatory function (G-code/job operation code) 28
- 3.1.8 H Tool height offset/data 29
- 3.1.9 I Auxiliary axis in X-axis direction 29
- 3.1.10 J is an auxiliary axis in Y-axis. It is used in CNC milling programming 29
- 3.1.11 K is an auxiliary axis in the Z-axis 30
- 3.1.12 L is used as a subprogram number or L is used as a number of repetition (loops) in canned cycle 31
- 3.1.13 M Miscellaneous code (M-code/Machine operating code) 31
- 3.1.14 N Block number/Sequence number/Line number in CNC program 31
- 3.1.15 O Program number/Program name 31
- 3.1.16 P is used as a block sequence number 32
- 3.1.17 Q is used as a Line number in some canned cycles in turning machine 32
- 3.1.18 R denotes radius and R is used for radius profile in CNC programming 32
- 3.1.19 S Spindle speed is the angular velocity of the work piece is called the spindle speed 32
- 3.1.20 T Tool T is used as a cutting tool in CNC programming 32
- 3.1.21 U Incremental axis in X-axis direction 32
- 3.1.22 V Incremental axis in Y-axis direction 33
- 3.1.23 W Incremental axis in Z-axis direction 33
- 3.1.24 X Main axis in X-axis direction 33
- 3.1.25 Y Main axis in Y-axis direction 33
- 3.1.26 Z Main axis in Z-axis direction 33
- 3.2 How to Write a CNC Program?/Write the Procedure of CNC Program? 34
- References 35
- 4 Cutting Tool Geometry Settings in CNC Software 37
- 4.1 What is the Cutting Tool Geometry in CNC Software? 37
- 4.2 Another Example of Tool Offset/Geometry 38
- 4.3 What is Cutting Tool Offset (Wear)? 39
- 4.4 An Example of the Tool Offset (Wear) 40.
- 4.5 What are Tool Offset Geometry and Tool Offset Wear in CNC Turning Machine? 41
- 4.6 What is Tool Nose Radius in CNC Machine? 41
- 4.7 What is Tool Tip Location in CNC Machine? Is it Same for All CNC Turning Machines? 42
- 4.8 Where You Enter Tool Nose Radius and Tool Tip Location? 44
- References 44
- 5 Dimension Methods, Machine Zero, Work Zero and Machine Axis 45
- 5.1 What is Absolute Dimension and Increment Dimension? 45
- 5.1.1 Absolute Dimension (G90) 45
- 5.1.2 Incremental Dimension (G91) 45
- 5.2 What is Diametrical Method and Radius Method? 46
- 5.2.1 Diametrical Method 46
- 5.2.2 Radius Method 47
- 5.3 What is the Machine Zero? 47
- 5.4 What is the Work Zero Offset/Origin (0, 0) in CNC Turning Machine and What is the Importance of the Work Zero in CNC Machine? 48
- 5.5 What is the Importance of the Central Axis of the Spindle in CNC Turning Machine? 49
- 5.6 How Many Axis in CNC Turning Machine? 49
- 5.6.1 Z-Axis (When Cutting Tool Moves Towards to Work Piece Length, Which is Called Z-Axis) 51
- 5.6.2 Some Important Facts About X = 0 & Z = 0
- 51
- 5.6.2.1 Before CNC programming and running the CNC turning machine, the programmer must know about the X = 0 & Z = 0. It means, programmer should know where is X = 0 (zero) and Z = 0 (zero) situated 52
- 5.6.2.2 Always in CNC turning machine, the value of X-axis will be zero (X = 0) in the center of the rotating work piece. It is a universal truth for turning machine 52
- 5.7 In Some Special Cases, We Can Take Z = 0 Anywhere on the Work Piece Surface. It Depends on the Machining Condition 52
- References 53
- 6 Turning Machine and Its Coordinates 55
- 6.1 What is the Importance of the Coordinate System in CNC Machine? 55
- 6.2 Find the Coordinates of Given Figure in Absolute Method (G90 Code) 55
- 6.3 Find the Absolute (G90) Coordinates of Given Figure in Diametrical () Method 56
- 6.3.1 In Turning Machine X-Axis is a Diametrical Axis, During Programming and Coordinates X Will Use with Diameter Value 58.
- 6.3.2 In Turning Machine Z-Axis Works in Length, During Programming and Coordinates Z Will Use with Length Value 58
- 6.3.2.1 In Figure 6.7, all length dimensions will be count in Z-axis with negative value because whole work piece is coming inside the negative zone (left side from work zero) of the Z axis. So length dimension will write with negative sign 59
- 6.3.2.2 All diametrical dimensions (10, 25) are in X-axis, so it will use with X-axis with positive value (+) because cutting tool cuts the material from above the center line and above the center line value of the X is always positive (+).