1INDUSTRIAL TRAINING

ON

CNC MACHINES

UNDER THE GUIDANCE OF

Er. Sanjay Jindal (DGM Maintenance)

Submitted By: Er. Sahil Gupta Roll NO: 2110003

2CNC Machines

Computer Numerical control (CNC) is the Automation of Machine Tools that are operated by abstractly programmed commands encoded on a storage medium, as opposed to controlled manually via hand wheels or levers, or mechanically automated via cams alone.

Modern CNC systems, end-to-end component design is highly automated using Computer-aided Design (CAD) and Computer-aided Manufacturing (CAM) programs. The programs produce a computer file that is interpreted to extract the commands needed to operate a particular machine via a postprocessor, and then loaded into the CNC machines for production.

Basic CNC Principle

All computer controlled machines are able to accurately and repeatedly control motion in various directions. Each of these directions of motion is called an axis. Depending on the machine type there are commonly TWO to FIVE axes.

X,Y,Z – Axis Cartesian Coordinate System

X,Y,Z,A,B – Axis CNC Coordinate System

A: Rotary axis along X - Axis B: Rotary axis along Y - Axis

4Key

ConceptNumber

OneCYCLESTART

FEEDHOLD

EDIT

AUTO

MDI JOG

HANDLE

ZERORETURNMODE

0%

100%

200%

FEEDRATEOVERRIDE

10%

25% 50%

100%

RAPIDOVERRIDE

1

12

TURRET INDEX2

345

67

8 9 10 11

SLOW FAST

EMERGENCYSTOP

FANUC 10T

POWERON

OFF

O N G P AX Y Z Q BI J K R C

F D H L #M S T /EOB

U V W

Sp

E ? @ @,

[ ] ( ) *

PAGE CURSOR

SHIFT

7 8 94 5 61 2 3- 0+ = CAN

RESET

START

CALC

INPUT

NC/PC

AUX

X00.0000Z00.0000

X ZX1

X10X100

0

ON

OFFDRYRUN

SINGLEBLOCK

MACHINELOCK

OPTIONALSTOP

BLOCKDELETE

X+

X-

Z-

JOYSTICK

Z+

ON OFF

SPINDLE

ORIGIN

X Z

0%100%

130%

SPINDLE LOAD

0%100%

130%

AXIS LOAD

X Z

OD ID

CLAMPDIRECTION

OFF ON

MEMORYPROTECT

CHUCK TAILSTOCKKey concept #2From programmer’s viewpoint

You must understand the machine you’ll be working with!

From operator’s viewpointKey concept #1

In key concept #2 we look at the machine from a programmer’s viewpoint

In key concept #1 we look at the machine from an operator’s viewpoint

5

Machine Configurations(2-axis Only)

Front view of machine

Headstock & Spindle Work-holding

Device

JobTailstock

BodyCenter

Turret

8

N0020: Instruction Number G00: Tool Not at Home position G57: Rotation of axis after tool base position S500: Speed of Rotation 500Rpm M04: Bypass Flag OR alarm

Operator’s Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

10

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

11

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

12

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

13

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

14

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

15

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

16

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

17

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

18

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

19

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

20

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

21

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

22

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

23

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

24

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

25

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

26

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

27

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

28

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

29

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

30

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

31

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

32

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

33

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

34

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

35

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

36

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

37

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

38

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

39

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

40

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

41

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

42

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

43

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

44

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

45

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

46

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

47

Z Axis- +

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

48

Z Axis- +

Z is the length controlling axis

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

50

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

51

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

52

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

53

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

54

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

55

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

56

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

57

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

58

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

59

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

60

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

61

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

62

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

63

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

64

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

65

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

66

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

67

X A

xis

-

+

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

68

X A

xis

-

+X is the diameter controlling axis

Instruction : N0020 G57 G00 X3.0 Z3.5 S500 M04

X A

xis

-

+

3.000

X3.0

If you want to turn a 3.0 inch diameter…X3.0 will be the commanding word

3.500

If you want to turn a 3.5 inch Length… will be the commanding word

Z3.5

Programmer’s View

First motive of the programmer is to get the machine ready for production by changing the current program and then analyse the problem in the machine due to which the breakdown occurs.

71 ATC NOT WORKING

STAGE – 1 : Check the Problem using CNC Ladder Logic

Input of “Tool arrived” is not coming.a)Check the tool positionb)Fix tool in pocketc)Check other conflictsd)Bypass the input X067e)Look over the process for one cyclef)Handover the machine to Operator.

Result : Machine is ready for production

STAGE – 2 :Find Actual Cause of Problem

STAGE -3 : STAGE – 4 :KAIZEN POKA YOKE

STAGE – 5 : STAGE - 6WHY – WHY ? FAULT TREE

72INITIAL: X067 is NOCause : Limit Switch input is missing

ACTION : Bypass X067 (say with M054 NC)Result : Tool Clamped

73STAGE – 2 : Actual Cause of Problem a) Limit Switch input missing

b) PDB Not Working c) Strobe Length Increased d) Nut Opened.

STAGE – 3 : KAI ZEN - Change For Better

Limit Switch Proximity SwitchREPLACED

a) Increased Performanceb) Reliabilityc) Life about 15yearsd) Delay Decreasede) Easy to replace

74STAGE – 4 : POKA-YOKE Mistake-Proofing

BEFORE AFTER

This mechanism in a manufacturing process is that which helps an equipment operator to avoid (YOKE) mistakes (POKA). The purpose is to eliminate product defects by preventing , correcting , or drawing attention to human errors as they occur.

Using one NUT make the length of strobe increased on prolong use. Bt using two NUTs, one after other make it fix for long use which reduces human as well as mechanical errors. This helps in reducing required maintenance.

75STAGE – 5 WHY –WHY ?

76STAGE –6 FAULT TREE

78

Name :- Sahil Gupta

Roll No. :- 2110003

Branch :- E.C.E.