Cnc Exercises

Boxford DUET

CNC Tutorials and Exercises

CNC Tutorials and Exercises

Boxford DUET

Tutorial 1 CNC Tutorials and Exercises

Tutorial 1:

X and Y Co-ordinate Calculation Absolute and Incremental Co-ordinates This tutorial gives examples of absolute co-ordinates and incremental co-ordinates. Absolute Co-ordinates The code G90 is used to select this type of programming. Before programming commences the points on the path to be machined are defined relative to the workpiece datum:

10

Y+

9

D C

8 7 6

B

5 4 3

A

2 1

X-

-10 -9 -8 -7 -6 -5 -4 -3 -2 -1-1 -2

X+ 1

2

3

4

-4 -5

F

6

7

8 9 10

H

-3

E

5

ORIGIN X0 Y0

G

-6 -7 -8 -9 -10

Y-

Examples of these co-ordinates are shown in the first table on the next page.


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The Z axis is the vertical axis and the datum used is normally the surface of the work. Z is positive when moving away from the surface and negative when moving towards or into the surface. POINT

DATUM

A

B

C

D

E

F

G

H

X Y

0 0

5 4

10 5

-4 5

-9 7

-7 -3

-4 -6

7 -5

5 -2

Incremental Co-ordinates The code G91 is used to select this type of programming. The points on the path to be machined are defined relative to the previous position. The points for the example on the previous page are shown in the table below.

POINT

DATUM

A

B

C

D

E

F

G

H

X Y

0 0

5 4

5 1

-14 0

-5 2

2 -10

3 -3

11 1

-2 3

The Z axis is again the vertical axis, and the points are defined relative to the previous position; positive when moving away from the surface and negative when moving towards or into the surface.

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Exercise 1 : Calculation of Co-ordinates

Tabulate the positions of the points A to H shown in the illustration below: a)

in absolute co-ordinates

b)

in incremental co-ordinates Y+ 6

D

5 4

C

A

3

B

2 1

X-8

-7 -6

-5

-4

F

-3

-2

X+ 1

-1 -1

2

4

5

G

-2 -3

H

-4

E

3

-5 -6

Y-

6

7

8


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Linear Interpolation This tutorial illustrates the use of the G01 code; cutting takes place in a straight line at a controlled feed rate. Consider the component illustrated below; it is required to mill the two L shaped slots. 45

C

D

20

B

A

15

50

Tutorial 2:

15

F 20

Y

E 30

80 Material: Grooves: Tool change at: Tool used:

X

15mm thick Plastic 5 wide x 2 deep X 0, Y 0, Z 25 5mm Slot Drill

Absolute Co-ordinates The absolute co-ordinates of the points are shown in the table below: POINT

A

B

C

D

E

F

T.C.

X Y

15 15

15 35

45 35

65 35

65 15

35 15

0 0

The program can be written in tabulated format as shown on the following page. Note: G00 is a default value and need not be programmed. The first tool is selected when entering the program into the computer.

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DRAWING NUMBER

NOTES


DUET PROGRAMMING SHEET-MILLING TUT 2/1

TITLE

G

ABSOLUTE PROGRAMMING

N10

90

METRIC UNITS

N20

71

TOOL CHANGE

N30

SPINDLE

N40

M

1 OF

CO-ORDINATES

X

Y

Z

0

0

25

I

J

FEED RATE

SPINDLE SPEED

F

S

03

1500

2mm ABOVE POINT A

N50

FEED TO 2 DEEP

N60

01

15

POINT B

N70

01

15

POINT C

N80

01

45

15

2 –2

2mm ABOVE WORK

N90

ABOVE POINT D

N100

FEED TO 5 DEEP

N110

01

POINT E

N120

01

POINT F

N130

01

2mm ABOVE WORK

N140

PARK POSITION

N150

05

END OF PROGRAM

N160

30

1

PROGRAMMED BY

SEQUENCE PREP MISC No. FUNCTION FUNCTION

N

SHEET No.

35

125 125 125

2 65 –2 15

125

35

125 2

0

125

0

25


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Using compact format, the program for the component shown previously will be as follows: N10 N20 N30 N40 N50 N60 N70 N80 N90 N100 N110 N120 N130 N140 N150 N160

G90 G71 X0 M03 X15 G01 G01 G01 Z2 X65 G01 G01 G01 Z2 M05 M30

Y0 S1500 Y15 Z-2 X15 X45

Z25

Z-2 Y15 X35

F125 F125 F125

X0

Y0

Z2 F125 Y35 F125 F125

Z25

Incremental Co-ordinates The incremental co-ordinates for the component are shown in the table below. Using these co-ordinates the program can be written as shown as follows: POINT

TOOL CHANGE

A

B

C

D

E

F

X Y

0 0

35 35

0 20

30 0

20 0

0 -20

-30 0

T.C. FROM F -35 -15

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Using these co-ordinates the program can be written as shown as follows:

DUET PROGRAMMING SHEET-MILLING

DRAWING NUMBER

TUT 2/2

TITLE

N

G


N10

90

METRIC UNITS

N20

71

TOOL CHANGE

N30

INCREMENTAL PROGRAMMING

N40

SPINDLE START RAPID TO 2mm ABOVE A

N50

M

OF 1

PROGRAMMED BY


NOTES

SHEET No. 1

CO-ORDINATES

X

Y

Z

0

0

25

15

15

–23

I

J

FEED RATE

SPINDLE SPEED

F

S

91 03

–4

1500

FEED TO mm DEPTH

N60

01

FEED FROM A TO B

N70

01

0

20

125

125

FEED FROM B TO C

N80

01

30

0

125

RAPID TO CLEARANCE PLANE

N90

RAPID TO 2mm ABOVE D

N100

FEED TO 2mm DEPTH

N110

01

FEED FROM D TO E

N120

01

0

–20

125

FEED FROM E TO F

N130

01

–30

0

125

RAPID TO CLEARANCE PLANE

N140

STOP SPINDLE RAPID TO PARK POSITION

N150

05

END OF PROGRAM

N160

30

4 20

0 –4

125

4 –35

–15

23

1.

Examine the program listed

2.

Enter the program into the computer

3.

Simulate the machining process and compare the movement of the cutter with the program


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Exercise 2: Linear Interpolation - Absolute Co-ordinates

1.

For the component shown below, use a programming sheet and write a program for the cutter to cut a groove along the path from A to H.

2.

Enter your program into the computer and give it a test run.

3.

Edit your program if necessary.

E

C

H

D

G

A

B

50

F

80

Y X

Material: Slots: Tool change at: Tool used:

15mm thick Plastic 5 wide x 2 deep X 0, Y 0, Z 25 5mm Slot Drill

Absolute Co-ordinates POINT

TOOL CHANGE

A

B

C

D

E

F

G

H

X Y

0 0

20 10

60 10

20 30

20 20

60 40

20 40

60 20

60 30

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Canned Cycles Hole Drilling and Pocket Milling Canned cycles are used to shorten and simplify the CNC program. This tutorial gives examples of the G81 Hole Drilling and G88 Pocket Milling cycles. G81 Hole Drilling This code drills a hole at the current X and Y values to a depth of Z measured incrementally from the face of the workpiece and then withdraws to the previous Z value i.e. 2mm clear. Enter Z incremental distance from the face of the workpiece to the bottom of the hole) F (feed rate)

B

C

20

4 x Ø 5 holes 10 deep

D

A

15

50

Tutorial 3:


20

40 80

Tool change at: X -5, Y -5 Tool used: 5mm Slot Drill

POINT

A

B

C

D

X Y

20 15

20 35

60 35

60 15


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The program for the component is as follows:

DRAWING NUMBER


TUT3/1

NOTES

TITLE


N

G

N10

90

METRIC UNITS

N20

71

TOOL CHANGE

OF 1

PROGRAMMED BY

TUT 3/1


SHEET No. 1

M

CO-ORDINATES

X

Y

Z

N30

–5

–5

25

RAPID TRAVERSE 2mm ABOVE HOLE A

N40

20

15

2

SPINDLE ON 1500 rev/min

N50

DRILL A 10mm DEEP

N60

RAPID TRAVERSE TO B

N70

DRILL B

N80

RAPID TRAVERSE TO C

N90

DRILL C

N100

RAPID TRAVERSE TO D

N110

DRILL D

N120

SPINDLE STOP TOOL CHANGE

N130

05

END OF PROGRAM

N140

30

I

J

FEED RATE

SPINDLE SPEED

F

S

03

1500

81 20 81 60

35

60

15

81

81 –5

– 10

125

– 10

125

– 10

125

– 10

125

35

–5

25

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G88 Rectangular Milling This code mills a rectangular pocket. The tool should be positioned 2mm above the pocket centre on the previous line. Enter X

the side length of the rectangle

Y

the side width of the rectangle

Z

the distance from the workpiece face to the bottom of the pocket

J

the number of cuts

F

feed rate

2.5 Rad

15

50

The tool returns to its start point when the cycle is complete.

40 80

Material: Pocket: Tool change at: Tool used:

15mm thick Plastic 8 deep X -5, Y -5 5mm Slot Drill

The program for the above component is shown on the following page:


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DRAWING NUMBER

TUT3/2

TITLE

N

G

M


N10

90

METRIC UNITS

N20

71

RAPID TO TOOL CHANGE

N30


N40

2mm ABOVE CENTRE OF POCKET

N50

MILL POCKET

N60


N70

05

END OF PROGRAM

N80

30

OF 1

PROGRAMMED BY


NOTES

SHEET No. 1

CO-ORDINATES

X

Y

Z

–5

–5

25

I

J

FEED RATE

SPINDLE SPEED

F

S

03

1500 40

88

25

2

40

15

8

–5

–5

25

4

125

1.

Examine the two programs.

2.

Enter each program into the computer.

3.

Simulate the machining process for each program and compare the movement of the cutter with the program.

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Exercise 3:

Canned Cycles - Programming a Tool Change

For the component shown below: 1.

Tabulate the co-ordinates.

2.

Use a programming sheet and write a program to drill the holes mill the square pocket (For tool changing, refer to Section 9.9).

3.


4.


30

30

4 x Ø 3 through holes

10

50

30

20

60 80 15mm thick Plastic Material: Square Pocket: 5mm deep Tool change at: X 0, Y O


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Tutorial 4:

Circular Interpolation Clockwise and Counter-clockwise This tutorial illustrates the use of the code G02 (clockwise circular interpolation) and G03 (counter clockwise circular interpolation). Circular Interpolation Clockwise This code moves the table in such a way that a clockwise circular arc is cut in the work within a single quadrant. The cutter is positioned at the start of the arc on the previous line of the program. The arc may be in the X Y, X Z or Y Z plane:

Y

X

Y

X

Z

X - Y Plane

X - Z Plane

Z Y - Z Plane

- and can be complete (90°) or partial (less than 90°), within a single quadrant:

After entering G02 the following extra information is needed: X value Y value Z value

two of these values specify the co-ordinates of where the curve finishes, the other value must be left blank.

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I value the distance from the arc centre (incremental) to the tool position at the start of the cuts measured along: a)

the X axis when cutting in X-Y or X-Z plane

b)

the Y axis when cutting in the Y-Z plane J value the distance from the arc centre (incremental) to the tool position at the start of the cut measured along:

a)

the Y axis when cutting in the X-Y plane

b)

the Z axis when cutting in the X-Z or Y-Z plane Note that I and J are unsigned values. Alternatively the radius of the arc can be entered as the I value and J left blank. Clockwise Circular Interpolation (G02) Single quadrant 90° arc in the XY plane To mill from A to B arc of centre C clockwise interpolation (G02) CUTTER STARTS AT A

G = 02

X = 35

Y = 20

I=0

A

J = 10

10 R

Y C

30

a)

25

Datum

B X


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Single quadrant partial arc in the XY plane To mill from A to B arc of centre C clockwise interpolation (G02) G = 02

X = (25 + 5) = 30 A 30 o

Y = (20 + 8.66) = 28.66

I=0

10 R

B

Y

C

30

b)

25

X

To calculate co-ordinates of B, construct triangle BCD CD =

10 x cos60

= 10 x 0.5

=5

BD =

10 x sin60

= 10 x 0.866

= 8.66

Note that I and J are unsigned values

A B

X

60 o

C

Y

D

J = 10

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Circular Interpolation Counter-clockwise This code moves the table in such a way that a counter-clockwise circular arc is cut in the work within a single quadrant. The cutter is positioned at the start of the arc on the previous line of the program. As with the G02 code, the arc may be in the X-Y, X-Z or Y-Z planes

Y

X

Y

X

Z

X - Y Plane

X - Z Plane

Z Y - Z Plane

- and can be complete (90°) or partial (less than 90°), within a single quadrant:

After entering G03 the following extra information is needed: X value Y value Z value

two of these values specify the co-ordinates of where the curve finishes, the other value must be left blank.

I value the distance from the arc centre (incremental) to the tool position at the start of the cut measured along: a)

the X axis when cutting in X-Y or X-Z plane

b)

the Y axis when cutting in the Y-Z plane


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J value the distance from the arc centre (incremental) to the tool position at the start of the cut measured along: a)

the Y axis when cutting in the X-Y plane

b)

the Z axis when cutting in the X-Z or Y-Z plane Note that I and J are unsigned values. Alternatively the radius of the arc can be entered as the I value and J left blank. Counter-Clockwise Circular Interpolation (GO3) Single quadrant 90° arc in the XY plane To mill from B to A arc of centre C counter-clockwise interpolation (G03) G = 03

X = 25

Y = 30

A

I = 10

J=0

10 R

Y C

30

a)

25

Datum

B X

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Single quadrant partial arc in the X-Y plane To mill from B to A arc of centre C G = 03

X = 25

Y = 30

30 o

I=5

J = 8.66

10 R

A

B

Y

C

30

b)

25

X

To calculate co-ordinates of B, construct triangle BCD CD

= 10 x cos60

= 10 x 0.5

=5

BD

= 10 x sin60

= 10 x 0.866

= 8.66

Note that I and J are unsigned values

A B

X

60 o

C

Y

D


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Example

D

50

C

E

B

F

A 10

G

10 80 Cutter: Arcs: Radius: Tool change at:

Ø5 2 deep 10 X -5, Y -5

POINT

A

B

C

D

E

F

G

X Y

10 10

20 20

30 30

40 40

50 30

60 20

70 10

The program for the above component is shown on the following page. Note: Blocks N70 to N90 define the arc in terms of its radius. Blocks N100 to N120 define the arc in terms of the co-ordinates of its centre

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DRAWING NUMBER

NOTES


DUET PROGRAMMING SHEET-MILLING TUT4

TITLE

G


N10

90

METRIC UNITS

N20

71

TOOL CHANGE

N30

SPINDLE START

N40

1 OF 1

PROGRAMMED BY


N

SHEET No.

M

CO-ORDINATES

X

Y

Z

–5

–5

25

J

I

FEED RATE

SPINDLE SPEED

F

S

03

1500

POINT A

N50

FEED TO DEPTH

N60

01

10

10

2

A TO B

N70

02

20

20

10

B TO C

N80

03

30

30

10

–2

125

C TO D

N90

02

40

40

10

D TO E

N100

02

50

30

0

10

E TO F

N110

03

60

20

10

0

F TO G

N120

02

70

10

0

10

RAPID OUT

N130


N140

05

–5

–5

END OF PROGRAM

N150

30

2 25

1.

Examine the program.

2.

Enter the program into the computer.

3.

Simulate the machining process and compare the movement of the cutter with the program.

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Exercise 4: Circular Interpolation

10 Rad

D 50

A

J

H

25

C

G

E

B

10 Rad

F

10 Rad

10 80 Material: 15mm deep Plastic Slot: 5 wide, 2 deep Tool change at: X 0, Y 0

For the cutter path shown above: 1.

Tabulate the co-ordinates A to J.

2.

Use a programming sheet to write a program for the path of the cutter centre line.

3.


4.

Edit your program if necessary. Note: The curve must be programmed in a series of quadrants (90°).


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Tutorial 5:

Combining Operations and Tool Changing This tutorial uses some cutters not supplied with the machine. It illustrates how tool changes can be made and a number of operation can be carried out on one component. Sequence of Operations 80

D

A

4 x Ø 5 holes

F

20

Ø30

D

15

50

E

B

C

40

15 13

20

G

Material: Plastic Tool change at: X 0, Y 0 5

1. 2. 3.

Mill the steps Drill the holes Mill the 30mm diameter pocket

5

(8mm diameter cutter) (5mm diameter drill) (10mm diameter cutter)

Note: Tool Changing The program for the above component illustrates the method of programming a tool change; block N120 moves the cutter to a tool change position and block N130 calls up a new tool. M06

denotes a tool change -

I

gives the tool type,

J

the tool diameter, and

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The program is as follows: DRAWING NUMBER

NOTES

DUET PROGRAMMING SHEET-MILLING TUT 5

TITLE

G


N10

90

METRIC UNITS

N20

71

TOOL CHANGE ø CUTTER

M

CO-ORDINATES

X

Y

Z

N30

–5

–5

25

RAPID TRAVERSE 2mm ABOVE A

N40

1

54

2


N50

FEED TO DEPTH

N60

01

MILL FIRST STEP

N70

01

RAPID TRAVERSE 2mm ABOVE C

N80

FEED TO DEPTH

N90

01

MILL SECOND STEP

N100

01

TOOL CHANGE POSITION

N120

05

TOOL CHANGE (5mm DRILL)

N130

06

RAPID TRAVERSE OVER HOLE D

N140

SPINDLE ON

N150

DRILL D 17mm DEEP

N160

RAPID TRAVERSE OVER HOLE

N170

DRILL E

N180

RAPID TRAVERSE OVER HOLE F

N190

DRILL F

N200

N220

TOOL CHANGING POSITION

N230

I

J

SPINDLE SPEED

F

S

1500 –2

125

–5 79

–5

125 2 –2

125

55 –5

–5

125 25 2

20

15

6

2

03

1500

81 20

60

35

60

15

81

81 –5

– 17

125

– 17

125

– 17

125

– 17

125

35

81

05

2

FEED RATE

03

RAPID TRAVERSE OVER HOLE G N210 DRILL G

1 OF

PROGRAMMED BY


N

SHEET No.

–5

25


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DRAWING NUMBER

NOTES

TITLE

TUT 5

N

G

M

N240

RAPID TRAVERSE 2MM ABOVE CENTRE OF POCKET

N250

SPINDLE ON

N260

MILL POCKET

N270

SPINDLE OFF, RAPID FEED TO TOOL CHANGE POSITION

N280

05

END OF PROGRAM

N290

30

2

OF 2

PROGRAMMED BY


TOOL CHANGE 10mm DRILL

SHEET No.

CO-ORDINATES

X

Y

Z

06 40

25

I

J

2

10

FEED RATE

SPINDLE SPEED

F

S

2

03 89

1500 30

0

5

–5

–5

25

3

125

1.


2.


3.

Simulate the machining process and compare the movements of the cutters with the program.

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Exercise 5: Combining Operations

5

80

O3

5

O2

5mm Groove

5

2

15

50

5

Material: 15mm thick Plastic Tool change at: X 0, Y 0

For the component shown above: 1.

Write down the sequence of operations required to produce the part.

2.

Tabulate the co-ordinates required.

3.

Use a programming sheet to write a program.

4.


5.



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Subroutines A subroutine can be regarded as a personalised canned cycle for use in a program which has repetitive shapes. The illustration below shows such a component; the milled grooves can be programmed as a subroutine.

20

15

55

50

A

30

15

B

5

Tutorial 6:

20

5

Material: Grooves: Tool change at: A,B :

15mm thick Plastic 5 wide x 3 deep X 0, Y 0 start positions for subroutines

The codes used for subroutines are: M43 subroutine create On entering M43, a prompt is made for an identifying number to be given to the routine. The number is entered in the I column and may have a value from 1 to 99. The user should note this reference number and the purpose of the routine. The mode of programming is now changed: the line number automatically reverts to 10 and co-ordinate entry, if absolute, becomes incremental. There is no restriction on the range of G codes (except G25) and all the canned cycles are available.

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M44 subroutine terminate On entry of the signal to end the subroutine the line numbers of the original program are restored and the current absolute position of the tool is shown in the X, Y and Z columns. If the program was previously being entered with absolute co-ordinates, it reverts to its former style. M45 subroutine call On entering M45 a prompt is made to input the reference number of the subroutine in the I column. A search is made in the subroutine file and the first file found with that reference number is executed. Note: Care is needed when allocating subroutine identification numbers. The program for the previous illustration shows subroutine blocks S10 onwards being typed into the system immediately after block N50. After this the cutter is repositioned before calling up the subroutine and completing the program. Editing of subroutines The program EDIT facility can be used. If this is brought into use the program is displayed for editing but a further option (SUB) is offered: SUB

HELP

MENU

If SUB is chosen, then the subroutine is displayed for editing. 1.


2.


3.

Simulate the machining process and compare the movements of the cutters with the program.


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DRAWING NUMBER

NOTES

DUET PROGRAMMING SHEET-MILLING TITLE

G

N10

90

N20

71

N30 N40

POINT A

M

CO-ORDINATES

X

Y

0

0

Z

J

I

FEED RATE

SPINDLE SPEED

F

S

25

03

N50

SUBROUTINE FOR GROOVES

N60

POINT B

N70

SUBROUTINE FOR GROOVES

N80

45

N90

05

N100

30

ENTERED

S10

43

IMMEDIATELY AFTER BLOCK N50

S20

01

S30

01

S40

01

THE SUBROUTINE

S50

01

MACHINES THE GROOVES

S60

01

(INCREMENTALLY)

S70 S80

1 OF 1

PROGRAMMED BY


N

TOOL CHANGE

TUT 6

SHEET No.

1500 5

5

55

30

1

45

1

1 0

0

25

1 –3 15

125

20

125 – 15

125

– 20

125 3

44

125

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Exercise 6: Subroutines

50

20

20

20

5

20

15

20

25

20

5

20 30 55 80

Material: Grooves:

15mm thick Plastic 5 wide x 2 deep


Tabulate the co-ordinates required.

2.

Use a programming sheet to write a program; the L shaped grooves can be programmed using a subroutine.

3.


4.



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Tutorial 7:

Mirror Images This tutorial demonstrates how a program written as a subroutine can be reflected about the X axis or about the Y axis or about both the X and the Y axes. It supports both linear and circular interpolation. Consider the shape shown in illustration A, which has been drawn in the sequence 12, 2-3, 3-4 and 4-1. 2

3

1

A

4

If the X co-ordinates are reflected with Y co-ordinates unchanged, the shape becomes: 2

1

B

3

4

with the 1-2, 2-3, 3-4 and 4-1 sequence maintained Alternatively, if the X co-ordinates are kept constant and the Y co-ordinates reflected, the outcome is: 4

3

2

C 1

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If both the X and y co-ordinates are reflected the result becomes: 4

3

D 1

2

If a program which calls a subroutine containing the original shape is written, then any or all of the above variations may be implemented. The as programmed case is achieved by the usual method of calling the subroutine. The mirror facility is accomplished by inserting a line in the program after positioning the tool at the start of the cycle but prior to calling the subroutine. The entry is: G X Y

value 28 value 0 or 1 value either 0 or 1

For example To reflect the X co-ordinate with Y unchanged: Enter G28 with X = 1, Y = 0

B

To reflect the Y co-ordinate with X unchanged: Enter G28 with X = 0, Y = 1

C

To reflect both the X and the Y co-ordinates: Enter G28 with X = 1, Y = 1

D

To cancel the mirror facility: Enter G28 WITH X = 0, Y =0 Note: For mirror image programming incremental co-ordinates must be used.


Boxford DUET

Example

C

D

15

A

20

30

10

50

D' C' A' B'

B

10 30 50 80 Material: 15mm thick Plastic Slots: 5 wide x 3 deep Tool change at: X 0, Y 0

In the program for the above illustration, note that blocks S10 to S80 onwards are typed into the system immediately after block N40. 1.

Study the program.

2.


3.

Simulate the machining process and compare the cutter movements with the program.

Boxford DUET

DRAWING NUMBER

NOTES


DUET PROGRAMMING SHEET-MILLING TITLE

TUT 7

N

G

N10

90

METRIC UNITS

N20

71

TOOL CHANGE

N30

M

SPINDLE ON POINT A

N40

03

CALL SUBROUTINE

N50

45

POINT B

N60

MIRROR IMAGE REFLECT X CO-ORDINATE Y UNCHANGED CALL SUBROUTINE

N70

91

N80

28

N90

CO-ORDINATES

X

Y

Z

0

0

25

30

20

1

J

I

50

20

1

0 7

S20 TI S80 REPEAT N100

28


N110

90

START OF SHAPE C

N120


N130

91

MIRROR IMAGE REFLECT Y CO-ORDINATE X UNCHANGED CALL SUBROUTINE

N140

28

N150

0

0

30

30

0

1

45

7 S20 TO S80 REPEATS

CANCEL MIRROR IMAGE

N160

28


N170

90

START OF SHAPE D

N180


N190

91

MIRROR IMAGE REFLECT BOTH X AND Y CO-ORDINATES

N200

28

2

0

0

50

30

1

1

FEED RATE

SPINDLE SPEED

F

S

2000 7

45

CANCEL MIRROR IMAGE

1 OF

PROGRAMMED BY



SHEET No.

Tutorial 7 CNC Tutorials andTutorial Exercises 7

Boxford DUET

DRAWING NUMBER

NOTES


G

N210

M

2 OF

CO-ORDINATES

X

Y

Z

45

J

I

FEED RATE

SPINDLE SPEED

F

S

7 S20 TO S80 REPEATS

CANCEL MIRROR IMAGE

N220

28


N230

90

TOOL CHANGE

N240

05

END OF PROGRAM

N250

30

SUBROUTINE CREATE

S10

43

FEED TO DEPTH

S20

01

0

0

–3

100

SUBROUTINE SHAPE A INCREMENTAL

S30

01

– 10

0

0

100

S40

01

0

– 10

0

100

S50

01

10

–5

0

100

S60

01

0

15

0

100

0

0

3

S70 SUBROUTINE TERMINATE

S80

44

2

PROGRAMMED BY


N

CALL SUB ROUTINE

TUT 7

TITLE

SHEET No.

0

0

0

0

25

7

Boxford DUET


20

15

30

50

Exercise 7: Mirror Images

20 30 50 80 Material: 15mm thick Plastic Slots: 5 wide x 2 deep Tool change at: X 0, Y 0


Write a program to machine the grooved triangles using the mirror image technique.

2.

Enter your program on the computer and simulate the cutting action.

3.

Edit your program if necessary. The manufacture of the component shown below uses the G86 and G87 canned cycles.


Boxford DUET

Further Canned Cycles Pitch Circle Drilling and Dish Milling The manufacture of the component shown below uses the G86 and G87 canned cycles.

80

6 x Ø 5 holes 5 deep on 40mm PCD 50

Tutorial 8:

Dished pocket Ø30, 5 deep Ø10 at bottom


G86 Canned Cycle Pitch Circle Diameter Drilling This code produces a series of holes on a circular pitch. The tool is positioned at a 2mm stand off point above the centre of a hole on the PCD on the previous line. Enter: X

number of holes to be drilled (must not be less than two)

Z

incremental distance from the face of the workpiece to the bottom of the hole the distance from the circle centre (incremental) to the first hole measured along the X axis

I J F

as the I value but measured along the Y axis Feed rate

Boxford DUET


G87 Canned Cycle Dish Milling This code will mill out a circular dish-shaped pocket. The dish is produced by cutting a series of concentric circular pockets starting at X diameter, with successive circles getting deeper as they reduce in diameter, until the last circle is at Y diameter and depth Z. The total number of circles is J. Increasing the number of cuts will produce a better dish but the time taken will be greater. Enter X Y Z I

the top diameter the bottom diameter of the dish The incremental distance from the face of the workpiece to the bottom of the dish

J

For a complete dish enter zero, or for hollow circles (an outline around the edge) enter a value is the number of cuts to produce the dish

F

the feed rate at which the dish is to be milled

The cycle is best used in two stages. For the first stage enter I = 0; this will rough out a pocket, leaving a stepped profile. On calling the code again for the second stage enter a value for I = 1; this will mill around the circumference of the circles, thus smoothing the profile. The program for the illustration shown earlier is shown on the following page. 1.

Study the program.

2.


3.

Simulate the machining process and compare the cutter movement with the program.

4.

View the component in 3D.


Boxford DUET

DRAWING NUMBER

NOTES


TITLE

N

G

N10

90

METRIC UNITS

N20

71

X

03

N30

SPINDLE ON, Move to Centre of P.C.D. DRILL HOLES ON P.C.D.

N40

TOOL CHANGE

N60

05

TOOL CHANGE SPINDLE ON, Move to Centre of Pocket ROUGH MILL DISH

N70

06

N80

03

N90

FINISH MILL DISH

N100

PARK POSITION

N110

05

END OF PROGRAM

N120

30

N50

CO-ORDINATES

M

TOOL CHANGE ø5 DRILL

86

1 OF 1

PROGRAMMED BY



SHEET No.

Y

Z

0

0

25

40

25

2

6

5

I

J

FEED RATE

SPINDLE SPEED

F

S

2000 0

20

2

5

80

0

0

25

40

25

2

87

30

10

5

0

5

80

87

30

10

5

1

5

80

0

0

25

2000

Boxford DUET


Exercise 8: Use of Canned Cycles Pitch Circle Drilling and Dish Milling

80

50

8 x Ø 5 holes 5 deep on 40mm PCD

25

Dished pocket Ø25, 5 deep Ø10 at bottom



Write a program to machine

the holes on the P.C.D.

the dished pocket.

2.

Enter your program on the computer and simulate the cutting action.

3.



Boxford DUET

Tutorial 9:

Subroutines, Mirror Images and Circular Interpolation

4

2

50 45

3

1 7

30

5 8

5

20

6

All grooves 15 radius 2 deep 5 wide

20 35 45 60 80 Tool change at: X 0, Y 0

The following program uses a subroutine which will mill a 90° arc of radius 15mm counter-clockwise and 2mm deep. It then uses the G28 Mirror Image routine to mill the other three arcs. The program is shown on the following page. 1.

Study the program.

2.

Key in the program and run the simulation.

3.

Compare the cutter movements with the program.

Boxford DUET

DRAWING NUMBER

NOTES



TITLE

G

M


N10

90

METRIC UNITS

N20

71

TOOL CHANGE POSITION

N30

SPINDLE START

N40

OVER POINT 1

N50

SUBROUTINE CREATE

S10

FEED TO DEPTH

S20

01

MILL QUADRANT

S30

03

WITHDRAW TOOL

S40

SUBROUTINE TERMINATE

S50

44

SUBROUTINE CALL

N60

45

POINT 2

N70

ABOVE POINT 3

N80

CO-ORDINATES

X

0

Y

0

Z

J

I

SPINDLE SPEED

F

S

25 1500

60

30

1

43

9 -3 -15

15

125 15

3

90

9 45

45

20

30

1

0

N90

91

MIRROR IMAGE REFLECT X, Y UNCHANGED SUBROUTINE CALL

N100

28

CANCEL MIRROR IMAGE

N120

28

0

0

POINT 4

N130

90

35

45

ABOVE POINT 5

N140

20

20

INCREMENTAL PROGRAM

N150

91

MIRROR IMAGE REFLECT BOTH X AND Y SUBROUTINE CALL

N160

28

1

1

N110

1

45

45

2

FEED RATE

03

INCREMENTAL PROGRAM

N170

1 OF

PROGRAMMED BY


N

SHEET No.

9

1

9

125


Boxford DUET

DRAWING NUMBER

NOTES


TITLE

N N180

G 28

POINT 6

N190

90

ABOVE POINT 7

N200

INCREMENTAL PROGRAM

N210

91

MIRROR IMAGE REFLECT X, Y UNCHANGED SUBROUTINE CALL

N220

28

CANCEL MIRROR IMAGE

N240

POINT 8

N250

SPINDLE STOP. TOOL CHANGE

N260

END OF PROGRAM

N270

CO-ORDINATES

Y 0

Z

35

5

1

60

20

0

1

28

0

0

90

45

5

1

0

0

25

N230

M

X 0

45

05 30

2 OF

2

PROGRAMMED BY


CANCEL MIRROR IMAGE

SHEET No.

J

I

9

FEED RATE

SPINDLE SPEED

F

S

Boxford DUET


Exercise 9: Subroutines and Mirror Images

6

21

29

44

60

All grooves 15 radius 2 deep 5 wide

21 36 44 59 80 15mm thick Plastic Material: Tool change at: X 0, Y 0 5mm Slot Drill Tool used:


Write a program to mill the curved slots using a subroutine and mirror images.

2.


3.



Boxford DUET

Tutorial 10:

Datum Shift and Jump to Line For programs with repetitive elements, and as an alternative to creating a subroutine (M43), a datum shift (G57) can be used in conjunction with Jump to Block (G25) and Return from Jump (G26). Details of the above codes are: G25 Jump to Block This code enables a section of a program to be executed again. There are two restrictions on the use of G25: (a)

a G25 loop must not be called from within a subroutine,

(b)

a subroutine must not be called from within a G25 loop.

Enter in the S column the line number to which the jump is to be made. G26 Return from Jump After using a G25 the program executes from the line specified in the S column until a G26 is encountered. The program then reverts to the line following that from where the G25 call was made. The G26 is only operative after a G25 loop has been called. At all other times it is transparent. G57 Datum Shift This code enables the X Y datum to be altered by an amount specified in the X and Y columns. Enter X value - new absolute X datum Enter Y value - new absolute Y datum Note: The Z datum cannot be altered with G57. G53 Cancel Datum Shift This code is used to cancel a G57 datum shift, i.e. it makes X and Y shift equal to zero. The above techniques are illustrated in the following example.


15

10

20

15

50

15

Boxford DUET

15 20 50 Material: Slots: Tool change at: Tool used:

80 15mm thick Plastic 5 wide x 2 deep X 0, Y 0 5mm Slot Drill

The program is shown on the following page. 1.

Study the program.

2.


3.

Compare the cutter movements with the program.


Boxford DUET

DRAWING NUMBER

NOTES


TITLE

N

G

N10

90

METRIC UNITS

N20

71

TOOLPARK POSITION

N30

M

DATUM SHIFT TO X20 Y10

N40

SPINDLE START MOVE OVER NEW DATUM INCREMENTAL PROGRAMMING

N50

57

N60

91

FEED TO DEPTH

N70

01

CUT FIRST L SHAPE

N80

01

CUT FIRST L SHAPE

N90

01

RAPID TO CLEAR

N100

RAPID TO NEW POSITION

N110


N120

90

RETURN FROM JUMP

N130

26

CANCEL DATUM SHIFT

N140

53

DATUM SHIFT TO X50 Y20

N150

57

JUMP TO BLOCK N60

N160

25

CANCEL DATUM SHIFT

N170

53

TOOL PARK

N180

STOP SPINDLE

N190

05

END OF PROGRAM

N200

30

03

1 OF 1

PROGRAMMED BY



SHEET No.

CO-ORDINATES

X

Y

0

0

20

10

0

0

Z

I

J

FEED RATE

SPINDLE SPEED

F

S

25

2

-4 15

1500

125 125

15

125 4

-15

-15

-15

-15

50

20 60

0

0

25

Boxford DUET


25

50

25

Exercise 10: Datum Shift and Jump to Line

10

20

20 20 10 45 Material: Slots: Tool change at: Tool used:

80 15mm thick Plastic 5 wide x 2 deep X 0, Y 0 5mm Slot Drill


Write a program to mill the L-shaped slots using the Datum Shift and Jump to Line codes.

2.


3.


OPERATIONS SHEET

DRAWING NUMBER OPERATIONS NUMBER

DUET OPERATIONS SHEET - MILLING TITLE OPERATION

SHEET No.

OF

MATERIAL SPINDLE FEED

TOOL FEED

TOOL REQUIRED

PROGRAMMING SHEET

DRAWING NUMBER

NOTES


OF

PROGRAMMED BY

TITLE SEQUENCE PREP MISC No. FUNCTION FUNCTION

N

SHEET No.

G

M

CO-ORDINATES

X

Y

Z

I

J

FEED RATE

SPINDLE SPEED

F

S

Cnc Exercises

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