CNC FUNDAMENTALS AND PROGRAMMING

TThis text-book explains the fundamentals of NC/CNC machine tools and manual part programming which form essential portion of course on Computer Aided Manufacturing (CAM). This book also covers advanced topics such as Macro programming, DNC and Computer Aided Part Programming (CAPP) in detail.

This book is divided into 6 major areas

Chapters 1 to 4 cover the history, fundamentals and structure of NC/CNC machine tools.
Chapter 5, 6 and 7 cover turning center programming in detail.
Various turning canned cycles are discussed in depth with the help of illustrative examples.
Chapters 8 and 9 are devoted to machining center programming. Drilling canned cycles are discussed in detail with relevant examples.
Chapter 10 and 11 cover advanced topics of subprogramming and macro programming.
Chapter 12 deals with the communications and networking of NC/CNC machine tools.
Chapter 13 and 14 explain the advanced programming using APT and CAD/CAM based programming respectively.

The book contains:

* 244
* 12
* 53
* 111

Self explanatory and neatly drawn drawings
Useful tables
Part programming exercises
Review questions at the end of all the chapters.

It is the fervent hope of the authors that this book will satisfy the needs of the Mechanical, Production, Mechatronics and Automobile Engineering students preparing for the B.Tech/B.E. examinations of all the Indian Universities, Diploma examinations conducted by various Boards of Technical Education, Certificate course as well as for the A.M.I.E., U.P.S.C., G.A.T.E., I.E.S. and other similar competitive and professional examinations. It should also be of an immense help to the practising Mechanical Engineers.

Price	:	Rs. 160-00
Edition	:	First Edition : 2009
ISBN	:	978-81-85594-98-9
Book Size	:	170 mm × 240 mm
Binding	:	Paperback with Four Colour Jacket Cover
Pages	:	264 + 16

1-1 1-2 1-3	History of NC Machines Introduction to Numerical Control (NC) Machine Tools CNC (Computer Numerical Control)
	Machine Control Unit
1-4	Differences between NC and Conventional Machine Tools
	(1) (2) (3) (4) (5) (6) (7) (8) (9)	Spindle drives Guideways Motion transmission Feed drives Machine tool structure Control unit Feedback unit Automatic tool changer (ATC) Automatic Pallet Changer (APC)
1-5	Advantages of CNC over NC
	(1) (2) (3) (4) (5) (6) (7) (8) (9)	Controller Memory Part program editing Cutter compensation Multipass canned cycles Advance part programming Tool path simulation Conversational programming Diagnostic
1-6	Advantages of NC and CNC over Conventional Machine Tools
	(1) (2) (3)	Increased flexibility More complex geometry Higher production rate
		(i) (ii) (iii)	Reduced set-ups Reduced lead time Reduced non-machining time
	(4) (5) (6) (7) (8) (9) (10) (11)	Higher accuracy and repeatability Reduced inspection Reduced operator skill Reduced scrap Reduced work-in-process inventory Elimination of profile tools Simpler fixtures Optimum cutting conditions
1-7	Limitations of NC/CNC machine tools
	(1) (2) (3) (4)	Cost High maintenance costs Not cost effective for low production levels Programming skill
	Role of NC/Cnc Technology in Modern Manufacturing
1-8	(1) (2) (3) (4) (5) (6) (7)	Machining Unconventional machining Fabrication and welding Press work Material handling and assembly Inspection and measurement Wood working
	Review Questions Top>>

2-1 2-1-1 2-1-2	Axes Designation Coordinate System Designating the Axes
	(1) (2) (3) (4)	Z axis X axis Y axis Rotary Motions
2-2 2-2-1 2-2-2 2-2-3 2-2-4 2-2-5 2-2-6 2-2-7 2-2-8 2-3 2-3-1 2-3-2 2-3-3 2-3-4 2-4 2-4-1	Axes System of Different Machine Tools Turning Center Vertical Machining Center (VMC) Horizontal Machining Center Turn mill centers Three axes planer Four axes Machining centers Five axes Horizontal Boring Machine Five axes Vertical Machining Center Reference Points The Grid System Machine Origin Part Origin Tool Reference Point CNC Control Systems Point-to-Point control (P-type)
	(1) (2) (3)	Axial Path 45° Path Linear Path
2-4-2 2-4-3	Line Control/Straight Cut Control (L-type) Continuous Path Control (C-type)
	(1) (2) (3) (4)	2-D Contouring control 2 1/2-D Contouring control 3-D Contouring control 4-D Contouring control
2-4-4 2-5 2-6	Example of P, L and C type controls 2-5 Automatic Tool Changer (ATC) 2-6 Automatic Pallet Changer Review Questions Top>>

3-1 3-2 3-3 3-3-1	Machine tool structure Guideways Transmission system Recirculating ballscrews
	(1) (2)	Double nut preloading Single nut preloading
3-3-2 3-4 3-4-1 3-4-2 3-4-3 3-5 3-5-1 3-5-1 3-6-1 3-6-1 3-6-2	Roller screw Drives Stepper motor Rotary servo motors Linear motor Open loop and closed loop control systems Open loop control system Closed loop control system Feedback devices Incremental optical encoders Absolute optical encoders
	(1) (2) (3)	Pure binary code Gray code Gray excess code
	Review questions Exercise Top>>

4-1	Coding Systems
	(1) (2) (3)	Fixed sequential format Tab sequential format Word address format
4-2	Types of Codes
	(1) (2) (3) (4) (5) (6) (7)	Sequence or block number Preparatory code Miscellaneous code Axis words Feed word Speed word Tool number
4-2-1 4-2-2 4-2-3 4-3 4-4 4-4-1 4-4-2 4-5 4-6 4-6-1 4-6-2	Preparatory codes Miscellaneous Codes Modal and Non-modal codes Decimal point programming Absolute and Incremental Positioning Absolute Positioning Incremental Positioning Diameter and Radius Programming Programming Functions Data Input Units Spindle Speed Control
	(1) (2)	Direction Spindle Speed
4-6-3 4-6-4 4-6-5 4-6-6	Feed Rate Control Coordinate System Preset Tool and Tool offset Program Control
	(1) (2) (3) (4)	M00: Program stop M01: Optional stop M02: End of program M30: Program stop and rewind
	Review Questons Top>>

5-1 5-2 5-3	Rapid Traverse (G00) Linear Interpolation (G01) Circular interpolation (G02/G03)
	(1) (2) (3)	Cutting direction (G02 or G03) Arc end point coordinates Radius of arc or center of arc
5-4	Method 1: Radius of arc programming Method 2: Center of arc programming Tool compensations
	(1) (2) (3)	Geometry offsets Wear offsets Tool nose radius compensation
5-4-1 5-4-2 5-4-3 5-5 5-6	Geometry offsets Wear offset Tool nose radius compensation Automatic reference point return (G28) Dwell Review Questions Exercise Top>>

8-1 8-2 8-3 8-3-1 8-3-2	Rapid traverse (G00) Linear interpolation (G01) Circular interpolation (G02/G03) Circular interpolation for arcs greater than 180° Programming of full circle in one block
	(1) (2)	Radius of arc programming Center of arc programming
8-4 8-5 8-5-1	Profile milling Cutter compensations Cutter radius compensation
	(1) (2) (3) (4) (5) (6) (7)	Offset plane selection and offset vector Cutter radius compensation to the left (G41) Cutter radius compensation to the right (G42) Ramp on move Ramp off move – cutter compensation cancel (G40) Tool movements in offset mode Change of the cutter compensation value
8-5-2 8-5-3 8-6	Tool length compensation Tool wear compensation Automatic reference point return (G28) Review questions Exercise

9-1	Syntax of drilling canned cycles
	(1) (2)	Return to the initial level (G98) Return to R level (G99)
9-2 9-3 9-4 9-5 9-6 9-7 9-8 9-9 9-10 9-11 9-12 9-13 9-14 9-15	Cancel the drilling canned cycle (G80) Spot drilling cycle (G81) Counter boring cycle (G82) Deep hole peck drilling cycle (G83) High speed peck drilling cycle (G73) Right-hand tapping cycle (G84) Left-hand tapping cycle (G74) Boring cycles (G85,G86) Back boring cycle (G87) Boring cycle with manual retraction (G88) Boring cycle with dwell (G89) Fine boring cycle (G76) Polar coordinate system Local coordinate system using datum shift (G52) Review questions Exercise Top>>

11-1	Applications of macros
	(1) (2) (3) (4)	Part family Development of canned cycles Complex interpolations Controlling optional devices
11-2	Variables
	(1) (2)	As arguments In calculations
		(i) (ii) (iii)	Local variables [# 1 – # 33] Common Variables [#100 – #149] [#500 – #532] System Variables [#1000 – ]
11-3 11-4 11-4-1 11-4-2 11-4-3	Arithmetic expressions Flow control statements Unconditional branching Conditional branching Looping
	(1) (2)	WHILE-DO loop DO loop
11-5	Calling a macro Review questions Exercise Top>>

12-1 12-2 12-3 12-4	History Direct numerical control Distributed numerical control DNC software features
	(1) (2) (3) (4) (5)	File transfer File management NC editor Report generation Access control
12-5 12-6 12-6-1 12-6-2	Advantages of DNC DNC communications Parallel communications Serial communications
	(1) (2)	Synchronous serial communication Asynchronous serial communication
12-7 12-7-1	Networking Networking components
	(1) (2) (3)	Coaxial cables Twisted pair cables Optical fiber cables
12-7-2	Network topologies
	(1) (2)	Physical topology Logical topology
		(i) (ii) (iii) (iv) (v)	Bus network topology Ring network topology Star network topology Mesh network topology Tree network topology
12-8	Networking of CNC machine tools
	(1)	Wired DNC Networks
		(i) (ii)	RS232 DNC system Ethernet DNC system
	(2)	Wireless DNC Networks
		(i) (ii)	Ethernet wireless DNC system Bluetooth wireless DNC system
	Review questions Top>>

13-1	Introduction
	(1) (2) (3)	Arithmetic calculations Cutter offset computation Postprocessing
13-2 13-3 13-3-1	Coordinate system Language features Keywords
	(1) (2)	Major words Minor words
13-3-2	Symbols
	(1)	Subscripted symbols
13-3-3	Other features
	(1) (2) (3) (4)	Numbers Angles Arithmetic operators Library functions
13-4 13-4-1 13-4-2 13-4-3	APT statements Postprocessor statements Auxiliary statements Geometry statements
	(1) (2) (3) (4) (5) (6) (7)	Point Line Circle Plane Patern Vector Zsurf
13-4-4	Tool motion statements
	(1) (2) (3) (4) (5) (6)	Tolerance specifications Startup and positioning statements Part, drive and check surfaces Startup statements Point to point motion statements Continuous path motion statements
13-5 13-6 13-7	Machining center canned cycles Macro programming Repetitive programming
	(1) (2)	Tracut Looping and branching
	Review questions Exercise Top>>

14-1	CAD/CAM systems
	(1) (2)	Standalone CAD/CAM systems Integrated CAD/CAM/CAE systems
		Step 1: Step 2:	Create the manufacturing model Setup the manufacturing data base and operations
			(1) Tooling data (2) Machine tools/Work cells (3) Fixture setups (4) Operation setup
		Step 3:	Define the NC-Sequences
			(1) Defining the machining features (2) Define the sequence of machining features
		Step 4: Step 5:	Create the toolpath (Cutter Location files) Post-processing
14-2 14-2-1	Evaluation of CAM software Turning
	(1)	2-axis turning
		(i) (ii) (iii) (iv) (v) (vi)	Contouring Hole making Roughing Copy roughing Grooving Threading
	(2)	Multi-spindle and multi-turret turning
14-2-2	Milling
	(1)	Simple milling
		(i) (ii) (iii) (iv) (v)	(i) Pocketing (ii) Facing (iii) Hole making (iv) Profiling (v) Thread milling
	(2)	Advanced milling
		(i) (ii)	Rotary axis Machining using 4th and 5th axis
	(3)	Machining of 3D freeform shapes
14-3	Conversational programming
		(1) Initialization module (2) Machining cycle module (3) Contour module (4) Tool module (5) Toolpath simulation module (6) Utility module
	Review questions Top>>