cnc lecture2

10/12/2016 1 Numerical Control Machines

CNC-MDP471

Design and Production Engineering Department,

Faculty of Engineering,

Ain Shams University.

Lecture 2

DR. AMR SHAABAN

10/12/2016 2

•Machine format

•Part programming

•G-code

•M-code

•Operation sequence

•Simple programming

10/12/2016 Dr.Amr Shaaban-Numerical Control Machines 3

MACHINE FORMAT

N4 G2 X±3.3 Y±3.3 Z±3.3 I±3.3 J±3.3 K±3.3 S4 F4 T2 M2

N code

G code

Positioning Circular

interpolation

Rotating speed

Feed

T code

M code

N0001 to N9999


PART PROGRAMMING

G-code Motion Functions

G00 G01 G02 G03

Linear motion Circular motion

Max Feed on Machine

“Rapid motion”

Specified feed value

“cutting motion” C.W C.C.W


PART PROGRAMMING

Motion Functions

G00 G01 G02 G03

Linear motion Circular motion

G00 X50 Y100 Z-199

G01 Z-210

G03 X-100 Y-50 I-50 J-20 (I&J from m/c zero) G03 X-100 Y-50 I-20J-50 (I&J from start point)

G03 X-100 Y-50 R10 (by radius)


PART PROGRAMMING

Working plans

G17 G18 G19


PART PROGRAMMING

Units designation

G20 Inch system

G21 Metric system mm

G94 Feed rate mm/min

G95 Feed mm/rev

G96 Cutting velocity m/min

G97 Rotating speed rpm


PART PROGRAMMING

Miscellaneous Functions [M-Code]

M00 Program Stop

M01 Optional Program Stop

M02 Program End [old]

M03 Spindle On Clockwise

M04 Spindle On Counterclockwise

M05 Spindle Stop

M06 Tool Change

07M Light Coolant On

M08 Heavy Coolant On

M09 Coolant Off

M30 Program End

M-code

http://www.cncezpro.com/m00m.cfm














http://www.cncezpro.com/m07t.cfm

http://www.cncezpro.com/m07t.cfm






OPERATION SEQUENCE

Example


OPERATION SEQUENCE

1 Facing

2 Turning from ϕ43 to ϕ 36


OPERATION SEQUENCE 3 Turning from ϕ36 to ϕ 17

4 Turning arc R3.5


OPERATION SEQUENCE

5 Chamfering

6 Grooving to ϕ10

7 PARTING OFF


SIMPLE PROGRAMMING

Step Description Details

1 Select the right holder Milling/turning

2 Raw material

specification

Milling: Block size (X*Y*Z)

Allowance for Z [Facing]

Allowance for X&Y [profiling]

Turning: cylinder (D*L)

Allowance for D [Turning]

Allowance for L [Facing + parting off + safety from part holder]

3 Decide the operation

sequence The sequence that achieve minimum tool changing

4 Tooling Check the machine tool list, prepare the T-code, and the

coordinate of the tool changer

5 Part program Write down the part program with the minimum block numbers


SIMPLE PROGRAMMING

20mm

ϕ10

Example

1 Select the right holder Turning machine

2 Raw material

specification

cylinder (12*40)

Allowance for D [Turning=2mm]

Allowance for L :

[Facing (2mm)+parting off (3mm)+safety from part holder(15mm)]

3 Decide the operation

sequence Facing/ longitudinal turning/ parting off

4 Tooling Facing tool(T01)/ turning tool(T02)/ parting off tool(T03)

Tool changer coordinate: 100mm from chuck face & 50mm from center

5 Part program Next slide


SIMPLE PROGRAMMING

20

ϕ10

15 3 2

ϕ12

50

100

Sa

fety

zo

ne

Pa

rtin

g o

ff

Facin

g

Tool changer

M/c zero

1

2 3


SIMPLE PROGRAMMING

50

Tool changer

20 15 3 2

100

ϕ10

ϕ12 M/c zero

N0010 G21 G90 G94 G97 Unit definition

N0020 G00 X100 Z100 T01 M06 Rapid motion to tool changer/ mounting facing tool

N0030 Z38 Facing starting point z

N0040 X14 S500 M03 Facing starting point x/ spindle rotate c.w

N0050 G01 X0 F20 M08 Facing

Facing start point X14, Z38

Facing end point X0, Z38


SIMPLE PROGRAMMING

50

Tool changer

20 15 3

62

ϕ10

ϕ12

Floating zero

Turning start point X10, Z2

Facing end point X10, Z-20

N0060 G92 X0 Z0 Temporary offset of m/c zero to the part face

N0070 G00 X100 Z62 T02 M06 Rapid motion to tool changer/ mounting turning tool

N0080 X10 Turning starting point x

N0090 Z2 Turning starting point z

N0100 G01 Z-20 F20 Turning


SIMPLE PROGRAMMING

50

Tool changer

20 15 3

62

ϕ10

ϕ12

Floating zero

Parting off start point X14, Z-21.5

parting off start point X0, Z-21.5

N0110 G00 X100 Z62 T03 M06 Rapid motion to tool changer/ mounting parting off tool

N0120 Z-21.5 Parting off starting point

N0130 X14 Parting off

N0140 G01 X0 F20 Ending parting off

N0150 G00 X100 M09 Tool away from part/ coolant off

N0160 M30 End program


THE END