Learn how to program and operate Computer Numerical Control (CNC) mills and lathes. Bridge the gap between your technical education and what you need to know to begin using CNC machine tools.
In this guide, you will learn about:
* Types of parts, materials, and machining operations that engineers, innovators and niche manufacturers often use.
* Examples of workholding techniques well suited to prototype and short-run production.
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www.autodesk.com/campaigns/fundamentals-of-cnc-machining
www.autodesk.com/content/dam/autodesk/www/campaigns/cnc/Fundamentals-of-cns-machining.pdf
Author(s): AUTODESK CAM
Publisher: Autodesk, Inc.
Year: 2014
Language: English
Pages: 256
Table of Contents
Chapter 1: Introduction & CNC Process Overview
Description ........................................................ 1-‐3
Prerequisites .................................................. 1-‐3
Audience ....................................................... 1-‐3
Course Design ................................................. 1-‐3
SRP vs. RP ....................................................... 1-‐4
Prototype vs. Production Machining .............................. 1-‐4
Required Tools and Equipment .................................... 1-‐4
Lessons and Appendices ........................................... 1-‐5
Instructional Resources ........................................... 1-‐5
Recommended Use ................................................... 1-‐6
Overview of CAD/CAM Process ...................................... 1-‐6
Chapter 2: Shop Safety
Overview ........................................................... 2-‐3
Safety Awareness .................................................. 2-‐3
Personal Conduct & Shop Etiquette ............................... 2-‐4
Shop Clothing ..................................................... 2-‐4
Proper Shop Attire Illustration .............................. 2-‐5
General Safety Practices ......................................... 2-‐6
CNC Safety Practices ............................................. 2-‐6
Safety Contract .................................................... 2-‐7
Safety Contract Form ......................................... 2-‐8
Chapter 3: CNC Tools
Overview .......................................... ................ 3-‐3
End Mills .......................................................... 3-‐3
Face Mill ......................................................... 3-‐4
Corner Radius Mill ............................................... 3-‐5
Slot Mill/Slotting Saw ........................................... 3-‐5
Center-‐Spot Drill ................................................. 3-‐5
Twist Drill ........................................................ 3-‐6
Tap ................................................................. 3-‐6
Reamer ............................................................. 3-‐7
Counterbore ........................................................ 3-‐8
Cutting Tool Fundamentals ........................................ 3-‐8
Rotational Direction .......................................... 3-‐8
Chip Formation ................................................ 3-‐8
Chip Load ..................................................... 3-‐9
Climb vs. Conventional Milling .............................. 3-‐9
Cutting Speeds and Feeds Formulas .............................. 3-‐10
Speed Formula ................................................. 3-‐11
Feed Formula .................................................. 3-‐12
Tap Feed Formula ............................................. 3-‐12
Speed/Feed Examples ............................................... 3-‐13
Milling Speed/Feed Example ................................... 3-‐13
Drill Speed/Feed Example ...................................... 3-‐14
Tap Speed/Feed Example ....................................... 3-‐15
Maximum Spindle Speed Example ................................ 3-‐16
Cutting Data ...................................................... 3-‐17
Best Practices Machining Parameters ......................... 3-‐18
Troubleshooting Speed/Feed Problems .......................... 3-‐19
Chapter 4: Coordinate Systems
Overview .......................................................... 4-‐3
Cartesian Coordinate System ..................................... 4-‐3
Number Line .................................................. 4-‐3
3D Cartesian Coordinate System ............................. 4-‐3
Quadrants ..................................................... 4-‐4
Units ............................................................. 4-‐5
Vertical Machining Center (VMC) Motion ......................... 4-‐5
CNC Motion Control ........................................... 4-‐6
CNC Machine Coordinates ...................................... 4-‐6
About Machine Home Position ................................ 4-‐7
Work Coordinate System (WCS) ................................... 4-‐8
WCS Example-‐1 ................................................ 4-‐9
WCS Example-‐2 ................................................. 4-‐10
WCS Example-‐3 ................................................. 4-‐11
Machine and Tool Offsets ........................................ 4-‐12
Machine Offset XY ............................................ 4-‐12
Machine Offset Z .............................................. 4-‐13
Tool Lenght Offset (TLO) .................................... 4-‐13
Chapter 5: CNC Programming Language
Overview .......................................................... 5-‐3
CNC Language and Structure ..................................... 5-‐3
Program Format ................................................ 5-‐4
CNC Editor ....................................................... 5-‐4
Alphabetic & Special Character Address Codes ................. 5-‐5
Alphabetic Address Code Definitions ........................ 5-‐5
G&M Codes ........................................................ 5-‐8
G-‐Codes ...................................................... 5-‐8
M-‐Codes ....................................................... 5-‐8
Select G-‐Code Definitions (Expanded) ...................... 5-‐9
Canned Cycles ..................................................... 5-‐10
Chapter 6: CNC Operation
Overview of CNC Setup and Operation .......................... 6-‐3
Machine and Tool Offsets ....................................... 6-‐5
Fixture Offset XY ........................................... 6-‐5
Fixture Offset Z ............................................ 6-‐6
Tool Length Offset (TLO) ................................... 6-‐7
Haas Control Face ............................................... 6-‐8
Haas Keyboard ................................................ 6-‐9
Start/Home Machine ................................................ 6-‐10
Load Tools ........................................................ 6-‐11
Set Tool Length Offset (TLO) ................................... 6-‐13
Set Fixture Offset XY ............................................ 6-‐17
Fundamentals of CNC Machining Set Fixture Offset Z ........... 6-‐21
Load CNC Program ................................................. 6-‐24
Run CNC Program ................................................... 6-‐26
Adjusting Diameter (CDC) Offsets ................................ 6-‐27
Shut Down CNC .................................................... 6-‐29
Chapter 7: 2D Milling Toolpaths
Overview ........................................................... 7-‐3
2D/3D/4X/5X Defined ............................................... 7-‐3
2D (Prismatic) Parts ......................................... 7-‐3
3D Parts ...................................................... 7-‐4
4-‐Axis Parts ................................................. 7-‐4
Standard CAD Views vs. CAM Views .............................. 7-‐6
CAD Features vs. Machining Features ............................ 7-‐6
Toolpaths by Type and Use ...................................... 7-‐7
2D Machining Features Example ............................... 7-‐8
2D Toolpath Terminology .......................................... 7-‐9
Facing ............................................................. 7-‐10
2D Contouring ..................................................... 7-‐11
Cutter Diameter Compensation .................................. 7-‐12
Pocketing ........................................................... 7-‐13
Slot Milling ...................................................... 7-‐14
Chamfer Milling ................................................... 7-‐15
Radius (Corner-‐Round) Milling ................................... 7-‐16
Center Drill ...................................................... 7-‐17
Drilling ........................................................... 7-‐18
Tapping ............................................................. 7-‐19
Chapter 8: CNC Turning
Overview ........................................................... 8-‐3
Lathe Components .............................................. 8-‐4
Spindle ........................................................ 8-‐5
Turret .......................................................... 8-‐6
Lathe Coordinate System .......................................... 8-‐8
Driven (Live) Tools ............................................... 8-‐9
Imaginary Tool Tip ................................................ 8-‐10
Part Datum ........................................................ 8-‐11
Tools and Tool Holders ........................................... 8-‐12
Chip Breaker .................................................. 8-‐12
Relief Angle .................................................. 8-‐13
Tool Cutting Angles .......................................... 8-‐13
Rake Angle .................................................... 8-‐14
Insert Designations ............................................... 8-‐15
Lathe Tool Types ................................................. 8-‐17
Face/Turn Tools ............................................... 8-‐17
Groove Tool ................................................... 8-‐18
Bore Tool ..................................................... 8-‐19
Thread Tool .................................................... 8-‐20
Cutoff Tool ................................................... 8-‐21
Cutting Speeds and Feeds ........................................ 8-‐22
Speed/Feed Example ............................................ 8-‐23
Cutting Feed Example ......................................... 8-‐24
Lathe Setup and Programming Example ............................ 8-‐25
Setup ........................................................... 8-‐26
Face ............................................................ 8-‐27
Rough ........................................................... 8-‐28
Finish .......................................................... 8-‐29
Groove ......................................................... 8-‐30
Thread .......................................................... 8-‐31
Drill .......................................................... 8-‐32
Bore ........................................................... 8-‐33
Cutoff .......................................................... 8-‐34
Fundamentals of CNC Chapter 9: 3D Toolpaths
Overview .......................................................... 9-‐3
3D Cutter Compensation ........................................... 9-‐3
Tolerances ........................................................ 9-‐4
3D Toolpath Setups .............................................. 9-‐6
3D Roughing ...................................................... 9-‐6
Parallel Finish .................................................. 9-‐7
Scallop Height ............................................... 9-‐8
3D Scallop ........................................................ 9-‐9
REST Milling ...................................................... 9-‐10
Pencil Toolpaths .................................................. 9-‐11
Conceptualizing 3D Toolpaths ..................................... 9-‐12
Chapter 10: Milling Setups
Overview ........................................................... 10-‐3
Fixture Components ................................................ 10-‐3
Subplates and Angle Plates .................................. 10-‐3
Clamps ......................................................... 10-‐4
Shoulder Bolts and Dowel Pins .................................. 10-‐5
Vise Accessories .................................................. 10-‐5
Hard Jaws ...................................................... 10-‐6
Soft Jaws ..................................................... 10-‐6
Appendix A: CNC Milling Work-‐Holding Examples
Project 1 : Install Vise ........................................ A-‐2
Project 2 : Install Vise Jaws ................................... A-‐4
Project 3 : Square Block ........................................ A-‐5
Project 4 : Contour Square Step ................................ A-‐13
Project 5 : Base ................................................. A-‐16
Project 6 : Housing ............................................. A-‐21
Project 7 : Fan Blades ......................................... A-‐23
Project 8 : Clamp ............................................... A-‐29
Project 9 : Fixture Plate ...................................... A-‐31
Project 10 : French Curve ...................................... A-‐33
Project 11 : Honeycomb ........................................... A-‐38
Project 12 : Bracket ............................................ A-‐40
Project 13 : Microwave Housing ................................. A-‐49
Project 14 : Geneva Gear ....................................... A-‐57
Appendix B: Alternate Tool Setting Methods
List of Common Methods ............................................ B-‐1
Using Paper ........................................................ B-‐2
1-‐2-‐3 Block on Finished Part Face ............................ B-‐3
1-‐2-‐3 Block and Dial Indicator ................................ B-‐4
Tool Probe ......................................................... B-‐4
Appendix C: CNC Process Planning Form
CNC Process Planning Form ....................................... C-‐1, C-‐2
Appendix D: G-‐M Code Reference
Milling G-‐ Codes ................................................ D-‐1
Milling M-‐Codes .................................................. D-‐2
Lathe G-‐Codes .................................................... D-‐3, D-‐4
Lathe M-‐Codes .................................................... D-‐4
Appendix E: Glossary
Glossary ............................................................. E-‐1, E-‐2
Appendix F: Drill Chart
Drill Chart ....................................................... F-‐1, F-‐2
Inch Pipe Threads ................................................. F-‐4
Metric Taps ....................................................... F-‐5
