FANUC Series 16i/160i/160is-MB, Series 18i/180i/180is-MB5, Series 18i/180i/180is-MB. Operator's Manual

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

NOTE

When the specified direction is reversed by decrease as shown in the figure below, the tool

moves in the opposite direction.

Movement of the tool

Program command

Start

Example

End

position

G46 X2.50 ;

position

Tool offset value

Equivalent command

+3.70

X-1.20 ;

Tool offset value

Tool offset can be applied to circular interpolation (G02, G03) with the G45 to G48 commands

only for 1/4 and 3/4 circles using addresses I, J and K by the parameter setting, providing that

the coordinate rotation be not specified at the same time. This function is provided for

compatibility with the conventional CNC tape without any cutter compensation. The function

should not be used when a new CNC program is prepared.

Tool offset for circular interpolation

Program

ÇÇ

N1 G46 G00 X_ Y_ D_ ;

N2 G45 G01 Y_ F_ ;

ÇÇN3ÇÇ

N3 G45 G03 X_ Y_ I_ ;

N4 G01 X_ ;

ÇÇÇ

Programmed tool path

ÇÇ

Actual tool path

ÇÇ

ÇÇÇ

D code should be used in tool offset mode (G45 to G48). However, H code can be used by

setting the parameter TPH (No. 5001#5) because of compatibility with conventional CNC tape

format. The H code must be used under tool length offset cancel (G49).

G45 to G48 are ignored in canned cycle mode. Perform tool offset by specifying G45 to G48

before entering canned cycle mode and cancel the offset after releasing the canned cycle

mode.

280

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

Examples

Program using tool offset

N12

N11

30R

N10

N13

30R

ÇÇÇ

N14

ÇÇÇ

OriginÇÇ

Y axis

Tool diameter

20φ

Offset No.

Tool offset value

+10.0

X axis

Program

N1 G91 G46 G00 X80.0 Y50.0 D01 ;

N2 G47 G01 X50.0 F120.0 ;

N3 Y40.0 ;

N4 G48 X40.0 ;

N5 Y-40.0 ;

N6 G45 X30.0 ;

N7 G45 G03 X30.0 Y30.0 J30.0 ;

N8 G45 G01 Y20.0 ;

N9 G46 X0 ;

Decreases toward the positive direction for

movement amount “0”. The tool moves in the -X

direction by theoffset value.

N10 G46 G02 X-30.0 Y30.0 J30.0 ;

N11 G45 G01 Y0 ; Increase toward the positive direction for movement

amount “0”. The tool moves in the +Y direction by

the offset value.

N12 G47 X-120.0 ;

N13 G47 Y-80.0 ;

N14 G46 G00 X80.0 Y-50.0 ;

281

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

When the tool is moved, the tool path can be shifted by the radius of the

14.4

tool (Fig. 14.4).

CUTTER

To make an offset as large as the radius of the tool, first create an offset

COMPENSATION B

vector with a length equal to the radius of the tool (start-up). The offset

vector is perpendicular to the tool path. The tail of the vector is on the

(G39-G42)

workpiece side and the head points to the center of the tool.

If a linear interpolation, corner offset, or circular interpolation command

is specified after start-up, the tool path can be shifted by the length of the

offset vector during machining.

To return the tool to the start point at the end of machining, cancel the

cutter compensation mode.

Corner offset

Circular interpolation

Circular

interpolation

Linear interpolation

Corner offset

Circular

interpolation

Linear

interpolation

Offset vector

Start up

Circular

Linear

interpolation

Cutter

Programmed path

ÇÇ

compensation

ÇÇ

cancel

Y axis

Tool center path

ÇÇ

Start position

X axis

Fig. 14.4 Outline of Cutter Compensation B

282

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

Format

D Start up

G00 (or G01) G41 (or G42)

IP_ IR_

H_ ;

(Cutter compensation

G41

: Cutter compensation left (Group 07)

start)

: Cutter compensation right (Group 07)

G42

: Command for axis movement

IR_

: Incremental value from the end position. Perpendicular to the offset

vector at the end position.

: Code for specifying the cutter compensation value (1 to 3 digits)

D Corner offset circular

G39

(or

IR_)

;

interpolation

G39 : Corner offset circular interposition (Group 00)

: Incremental value from the end position. Perpendicular to

IP_ (or) IR_

the offset vector at the end position.

D Cutter compensation

G40IP_ ;

cancel

G40 : Cutter compensation cancel (Group 07)

IP_

: Command for axis movement

D Selection of the offset

Offset plane

Command of the plane selection

IR_

plane

XpYp

G17 ;

Xp_Yp_

I_J_

ZpXp

G18 ;

Xp_Zp_

I_K_

YpZp

G19 ;

Yp_Zp_

J_K_

Explanations

D H code

Specify the number assigned to a cutter compensation value with a 1- to

3-digit number after address H (H code) in the program. The H code can

be specified in any position before the offset cancel mode is first switched

to the cutter compensation mode. The H code need not be specified again

unless the cutter compensation value needs to be changed.

Assign cutter compensation values to the H codes on the MDI panel. For

the specification of the cutter compensation value, see III-11.4.1 in the

section on operation.

The table below shows the range in which the cutter compensation values

can be specified.

Table 14.4 Valid range of cutter compensation values

Metric input

inch input

Cutter compensation value

0 to ±999.999mm

0 to ±99.9999inch

NOTE

The cutter compensation value corresponding to offset

No.0, that is, H0 always gets 0. It is impossible to set H0 to

any other cutter compensation value.

283

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

D Offset plane selection

Cutter compensation is carried out in the plane determined by G17, G18

and offset vector

and G19 (G codes for plane selection.). This plane is called the offset

plane. If the offset plane is not specified, G17 is assumed to be

programmed.

Compensation is not executed for the coordinates of a position which is

not in the specified plane. The programmed values are used as they are.

In the sequel, what vector is created, what offset calculation is made, by

an offset command, will be discussed on assumption that an XY plane is

selected. This discussion applies also when another plane is selected.

The offset vector is cleared by reset.

After the power is turned on, the length of the offset vector is set to zero

and the cutter compensation cancel mode is selected.

Notes

D Transition from the offset

cancel mode to the

cutter compensation

NOTE

mode (Start up)

A move command mode at the time of change from the

offset cancel mode to the cutter compensation mode, is

positioning (G00) or linear interpolation (G01). The circular

interpolation (G02, G03) cannot be used.

284

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

14.4.1

G41 offsets the tool towards the left of the workpiece as you see when you

face in the same direction as the movement of the cutting tool.

Cutter Compensation

Left (G41)

Explanations

D G00 (positioning) or

G41 X_ Y_ I_ J_ H_ ;

G01 (linear interpolation)

specifies a new vector to be created at right angles with the direction of

(I, J) on the end point, and the tool center moves toward the point of the

new vector from that of the old vector on the start point.(I, J) is expressed

in an incremental value from the end point, and is significant only as a

direction, and its amount is arbitrary.

ÇÇÇ

Tool center path

ÇÇÇÇÇ

Old vector

New vector ÇÇÇÇ

ÇÇÇÇÇ

ÇÇÇ

Start

position

(X, Y)

(I, J)

Programmed path

In case the old vector is 0, this command specifies the equipment to enter

from the cancel mode into the cutter compensation mode. At this time,

the offset number is specified by the H code.

ÇÇ

ÇÇÇ

Tool center path

ÇStart position

ÇÇÇÇÇ

New vector

ÇÇÇ

(X, Y)

(I, J)

Old vector=0

Programmed path

Unless otherwise specified, (I, J) are assumed to be equal to (X, Y). When

the following command is specified, a vector perpendicular to a line

connecting the start position and position (X, Y) is created.

G41 X_ Y_ ;

If, however, G00 is specified, each axis moves independently at the rapid

traverse rate.

ÇÇÇ

Tool center path

ÇÇÇÇÇ

Old vector

ÇÇÇÇÇ

New vector

ÇÇÇ

Start position

(X, Y)

Programmed path

285

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

D G02, G03

G41… ;

(Circular interpolation)

G02 (or G03) X_ Y_ R_ ;

Above command specifies a new vector to be created to the left looking

toward the direction in which an arc advances on a line connecting the arc

center and the arc end point, and the tool center to move along the arc

advancing from the point of the old vector on the arc start point toward

that of the new vector. This is, however, established on assumption the

old vector is created correctly.

The offset vector is created toward the arc center or opposite direction

against the arc center.

New vector

ÇÇÇÇ

Tool center path

ÇÇÇÇ

(X, Y)

Programmed path

ÇÇÇ

ÇÇÇÇÇ

Start position

ÇÇÇÇÇ

Old vector

ÇÇÇ

New vector

ÇÇÇÇ

(X, Y)

ÇÇÇÇÇ

ÇÇÇÇ

Tool center path

ÇÇÇÇ

Old vector

ÇÇÇÇ

Programmed path

ÇÇÇÇ

Start positionÇÇ

286

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

14.4.2

G42, contrary to G41, specifies a tool to be offset to the right of work piece

looking toward the direction in which the tool advances.

Cutter Compensation

G42 has the same function as G41, except that the directions of the vectors

Right (G42)

created by the commands are the opposite.

Explanations

D G00 (positioning) or

G42 X_ Y_ I_ J_ H_ ;

G01 (linear interpolation)

Programmed path

(I, J)

Start position

(X, Y)

ÇÇÇ

ÇÇÇÇ

Old vector

New vector

ÇÇÇÇÇ

ÇÇÇÇ

ÇÇÇÇÇ

ÇÇÇÇ

ÇÇÇÇÇ

Tool center path

ÇÇÇÇ

ÇÇÇ

ÇÇ

G42 X_ Y_ ;

Programmed path

(X, Y)

Start position

ÇÇÇ

Old vector New vector

ÇÇÇÇÇ

Tool center path

ÇÇÇÇÇ

ÇÇÇ

In the case of G00, however, each axis moves independently at the rapid

traverse rate.

287

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

D G02 or G03

G42… ;

(Circular interpolation)

G02 (or G03) X_ Y_ R_;

(X, Y)

ÇÇÇÇ

Programmed path

ÇÇÇÇ

New vector

ÇÇÇÇ

Tool center path

ÇÇÇ

ÇÇÇÇÇ

Start position

ÇÇÇÇÇ

Old vectorÇÇÇ

New vector

ÇÇÇÇ

(X, Y)ÇÇÇÇÇ

ÇÇÇÇÇ

Programmed path

Start position ÇÇ

Tool center path

ÇÇÇÇ

Old vector

ÇÇÇ

288

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

14.4.3

When the following command is specified in the G01, G02, or G03 mode,

corner offset circular interpolation can be executed with respect to the

Corner Offset Circular

radius of the tool.

Interpolation (G39)

Format

In offset mode

X_Y_

G39

X_Z_

;

Y_Z_

I_J_

G39

I_K_

;

J_K_

A new vector is created to the left (G41) or to the right (G42) looking

toward (X, Y) from the end point at right angles therewith, and the tool

moves along the arc from the point of the old vector toward that of the new

vector.

(X, Y, Z) is expressed in a value according to the G90/G91

respectively.

(I, J, K) is expressed in an incremental value from the end

point.

Case of G41

Old vector

New vector

Tool center path

(X, Y)or(I, J)

ÇÇÇ

ÇÇÇÇ

Programmed path

ÇÇÇÇ

ÇÇÇ

Case of G42

New vector

Old vector

Tool center path

(X, Y)or(I, J)

ÇÇÇ

ÇÇÇÇÇ

Programmed path

ÇÇÇÇÇ

ÇÇÇ

This command can be given in offset mode, that is, only when G41 or G42

has already been specified. Whether the arc is to turn clockwise or

counterclockwise, is defined by G41 or G42, respectively. This command

is not modal, and executes circular interpolation, whatever the G function

of group 01 may be. The G function of group 01 remains even though this

command is specified.

289

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

14.4.4

When the following command is specified in the G00 or G01 mode, the

tool moves from the head of the old vector at the start position to the end

Cutter Compensation

position (X, Y). In the G01 mode, the tool moves linearly. In the G00

Cancel (G40)

mode, rapid traverse is carried out along each axis.

G40 X_ Y_ ;

Tool center path

ÇÇÇÇÇ ÇÇÇÇÇ

(X, Y)

ÇÇÇÇÇ ÇÇ

Old vector

ÇÇÇÇ

Start position

Programmed path

This command changes the mode of the equipment from the cutter

compensation mode to the cancel mode.

When only G40; is specified, and X _ Y _ is not specified, the tool moves

by the old vector amount in the opposite direction.

NOTE

Cutter compensation cannot be canceled in the circular

interpolation (G02, G03) mode.

290

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

14.4.5

The offset direction is switched from left to right, or from right to left

generally through the offset cancel mode, but can be switched not through

Switch between Cutter

it only in positioning (G00) or linear interpolation (G01). In this case, the

Compensation Left and

tool path is as shown in Fig 14.4.5.

Cutter Compensation

Right

G41……… ;

G00 G42 X_ Y_ ;

ÇÇÇÇ

Tool center path

(normally, it is not straight.)

ÇÇÇÇÇ

Old vector

(X, Y)

ÇÇÇÇ

New

vector

Programmed path

ÇÇÇÇ

G42……… ;

G00 G41 X_ Y_ ( or I_ J_) F_ ;

ÇÇ

ÇÇÇÇ

Tool center path

ÇÇÇÇ

New

ÇÇÇÇ

vector

ÇÇÇÇ

(X, Y)or(I, J)

Old vector

ÇÇÇÇ

Programmed path

ÇÇÇÇÇ

ÇÇÇÇ

ÇÇ

Fig. 14.4.5 Switching the Direction of Cutter Compensation

291

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

14.4.6

The offset amount is changed generally when the tool is changed in the

offset cancel mode, but can be changed in the offset mode only in

Change of the Cutter

positioning (G00) or linear interpolation (G01).

Compensation Value

Program as described below:

G00 (or G01) X_ Y_ H_ ; (H_ indicates the number of a new cutter

compensation value.)

Fig.

14.4.6 shows how the tool is moved when the change in

compensation is specified.

ÇÇÇ

ÇÇÇÇÇ

Tool center path

ÇÇÇ

ÇÇÇÇÇ

New vector

ÇÇÇÇÇ

ÇÇÇ

Old vector

ÇÇÇÇÇ

Start position

Programmed path

(X, Y)

ÇÇÇÇ

ÇÇÇÇÇ

ÇÇÇÇ

ÇÇÇÇÇ

New vector

Old vector

ÇÇÇÇÇ

ÇÇÇÇ

Programmed path

Start position

(X, Y)

Fig 14.4.6 Change of the cutter compensation value in offset mode

292

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

14.4.7

If the tool compensation value is made negative (-), it is equal that G41

and G42 are replaced with each other in the process sheet. Consequently,

Positive/Negative

if the tool center is passing around the outside of the workbench it will

Cutter Compensation

pass around the inside thereof, and vice versa.

Value and Tool Center

Fig.

14.4.7 shows one example. Generally speaking, the cutter

Path

compensation value shall be programmed to be positive (+). When a tool

path is programmed as shown in (1), if the cutter compensation value is

made negative (-), the tool center moves as shown in (2).

If the cutter compensation value is changed to a negative value when tool

path (2) shown in Fig. 14.4.7 is programmed, the tool follows tool path

(1) shown in the same figure.

(1)

(2)

ÇÇÇ

Tool center path

ÇÇÇ

ÇÇ

Programmed path

Fig. 14.4.7 Tool Center Paths when Positive and Negative

Cutter Compensation Values are Specified

For a cornered figure (involved in corner circular interpolation) in

general, the cutter compensation value naturally cannot be made negative

(-) to cut the inside. In order to cut the inside corner of a cornered figure,

an arc with an appropriate radius must be inserted there to provide smooth

cutting.

WARNING

If the tool length offset is commanded during cutter

compensation, the offset amount of cutter compensation is

also regarded to have been changed.

293

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

Examples

20.0

40.0

R1=40.0

40.0

R2=20.0

20.0

N10

20.0

Y axis

ÇÇ

N11

ÇÇ

20.0

X axis

Unit : mm

N1 G91 G17 G00 G41 J1 X20.0 Y20.0 H08 ;

N2 G01 Z-25.0 F100 ;

N3 Y40.0 F250 ;

N4 G39 I40.0 J20.0 ;

N5 X40.0 Y20.0 ;

N6 G39 I40.0 ;

N7 G02 X40.0 Y-40.0 R40.0 ;

N8 X-20.0 Y-20.0 R20.0 ;

N9 G01 X-60.0 ;

N10 G00 Z25.0 ;

N11 G40 X-20.0 Y-20.0 M02 ;

(H08 is a tool offset number, and the cutter radius value should be stored in the

memory corresponding to this number).

294

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

When the tool is moved, the tool path can be shifted by the radius of the

14.5

tool (Fig. 14.5 (a)).

OVERVIEW OF

To make an offset as large as the radius of the tool, CNC first creates an

CUTTER

offset vector with a length equal to the radius of the tool (start-up). The

offset vector is perpendicular to the tool path. The tail of the vector is on

COMPENSATION C

the workpiece side and the head positions to the center of the tool.

(G40-G42)

If a linear interpolation or circular interpolation command is specified

after start-up, the tool path can be shifted by the length of the offset vector

during machining.

To return the tool to the start position at the end of machining, cancel the

cutter compensation mode.

Cutter

compensation

cancel

Start-up

ÇÇÇ

Fig. 14.5 (a) Outline of Cutter Compensation C

295

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

Format

D Start up

G00(or G01)G41(or G42)

IP_ D_ ;

(Tool compensation

G41

: Cutter compensation left (Group07)

start)

G42

: Cutter compensation right (Group07)

IP_

: Command for axis movement

: Code for specifying as the cutter compensation value(1-3digits)

(D code)

D Cutter compensation

;

G40

cancel

(offset mode cancel)

G40 : Cutter compensation cancel(Group 07)

(Offset mode cancel)

IP_

: Command for axis movement

D Selection of the offset

Offset plane

Command for plane selection

IP_

plane

XpYp

G17 ;

Xp_Yp_

ZpXp

G18 ;

Xp_Zp_

YpZp

G19 ;

Yp_Zp_

Explanations

D Offset cancel mode

At the beginning when power is applied the control is in the cancel mode.

In the cancel mode, the vector is always 0, and the tool center path

coincides with the programmed path.

D Start Up

When a cutter compensation command (G41 or G42, nonzero dimension

words in the offset plane, and D code other than D0) is specified in the

offset cancel mode, the CNC enters the offset mode.

Moving the tool with this command is called start-up.

Specify positioning (G00) or linear interpolation (G01) for start-up. If

circular interpolation (G02, G03) is specified, P/S alarm 34 occurs.

When processing the start-up block and subsequent blocks, the CNC

prereads two blocks.

D Offset mode

In the offset mode, compensation is accomplished by positioning (G00),

linear interpolation (G01), or circular interpolation (G02, G03). If two or

more blocks that do not move the tool (miscellaneous function, dwell,

etc.) are processed in the offset mode, the tool will make either an

excessive or insufficient cut. If the offset plane is switched in the offset

mode, P/S alarm 37 occurs and the tool is stopped.

296

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

D Offset mode cancel

In the offset mode, when a block which satisfies any one of the following

conditions is executed, the CNC enters the offset cancel mode, and the

action of this block is called the offset cancel.

1. G40 has been commanded.

2. 0 has been commanded as the offset number for cutter

compensation.

When performing offset cancel, circular arc commands (G02 and G03) are

not available. If a circular arc is commanded, an P/S alarm (No. 034) is

generated and the tool stops.

In the offset cancel, the control executes the instructions in that block and

the block in the cutter compensation buffer. In the meantime, in the case

of a single block mode, after reading one block, the control executes it and

stops. By pushing the cycle start button once more, one block is executed

without reading the next block.

Then the control is in the cancel mode, and normally, the block to be

executed next will be stored in the buffer register and the next block is not

read into the buffer for cutter compensation.

Start up

(G41/G42)

Offset cancel mode

Offset mode

Offset modecancel

(G40/D0)

Fig. 14.5 (b) Changing the offset mode

D Change of the Cutter

In general, the cutter compensation value shall be changed in the cancel

compensation value

mode, when changing tools. If the cutter compensation value is changed

in offset mode, the vector at the end point of the block is calculated for

the new cutter compensation value.

Calculated from the cutter

compensation value in the block

compensation value in the block N7

Programmed path

Fig. 14.5 (c) Changing the Cutter Compensation Value

297

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

D Positive/negative cutter

If the offset amount is negative (-), distribution is made for a figure in

compensation value and

which G41’s and G42’s are all replaced with each other on the program.

tool center path

Consequently, if the tool center is passing around the outside of the

workpiece, it will pass around the inside, and vice versa.

The figure below shows one example. Generally, the offset amount is

programmed to be positive (+).

When a tool path is programmed as in ((1)), if the offset amount is made

negative

(-), the tool center moves as in

((2)), and vice versa.

Consequently, the same tape permits cutting both male and female

shapes, and any gap between them can be adjusted by the selection of the

offset amount. Applicable if start-up and cancel is A type. (See II- 14.6.2

and 14.6.4)

(1)

(2)

ÇÇÇ

Tool center path

ÇÇÇ

ÇÇ

Programmed path

Fig. 14.5 (d) Tool Center Paths when Positive and Negative

Cutter Compensation Values are Specified

D Cutter compensation

Assign a cutter compensation values to the D codes on the MDI panel.

value setting

The table below shows the range in which cutter compensation values can

be specified.

mm input

inch input

Cutter compensation value

0 to ±999.999mm

0 to ±99.9999inch

NOTE

The cutter compensation value corresponding to offset No.

0, that is, D0 always means 0. It is impossible to set D0 to

any other offset amount.

Cutter compensation C can be specified by H code with

parameter OFH (No. 5001 #2) set to 1.

D Offset vector

The offset vector is the two dimensional vector that is equal to the cutter

compensation value assigned by D code. It is calculated inside the control

unit, and its direction is up-dated in accordance with the progress of the

tool in each block.

The offset vector is deleted by reset.

D Specifying a cutter

Specify a cutter compensation value with a number assigned to it. The

compensation value

number consists of 1 to 3 digits after address D (D code). The D code is

valid until another D code is specified. The D code is used to specify the

tool offset value as well as the cutter compensation value.

298

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

D Plane selection and

Offset calculation is carried out in the plane determined by G17, G18 and

vector

G19, (G codes for plane selection). This plane is called the offset plane.

Compensation is not executed for the coordinate of a position which is not

in the specified plane. The programmed values are used as they are.

In simultaneous 3 axes control, the tool path projected on the offset plane

is compensated.

The offset plane is changed during the offset cancel mode. If it is

performed during the offset mode, a P/S alarm (No. 37) is displayed and

the machine is stopped.

299

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

Examples

250R

C1(700,1300)

C3 (-150,1150)

P4(500,1150) P5(900,1150)

C2 (1550,1550)

650R

P3(450,900)

P6(950,900)

(1150,900)

(250,900)

P9(700,650)

(1150,550)

(250,550)

N10

Y axis

N11

ÇÇ

Unit : mm

X axis

ÇÇÇ

Start position

ÇÇÇ

G92 X0 Y0 Z0 ;

Specifies absolute coordinates.

The tool is positioned at the start position (X0, Y0, Z0).

N1 G90 G17 G00 G41 D07 X250.0 Y550.0 ; Starts cutter compensation (start-up). The tool is shifted to the

left of the programmed path by the distance specified in D07.

In other words the tool path is shifted by the radius of the tool

(offset mode) because D07 is set to 15 beforehand (the radius of

the tool is 15 mm).

N2 G01 Y900.0 F150 ;

Specifies machining from P1 to P2.

N3 X450.0 ;

Specifies machining from P2 to P3.

N4 G03 X500.0 Y1150.0 R650.0 :

Specifies machining from P3 to P4.

N5 G02 X900.0 R-250.0 ;

Specifies machining from P4 to P5.

N6 G03 X950.0 Y900.0 R650.0 ;

Specifies machining from P5 to P6.

N7 G01 X1150.0 ;

Specifies machining from P6 to P7.

N8 Y550.0 ;

Specifies machining from P7 to P8.

N9 X700.0 Y650.0 ;

Specifies machining from P8 to P9.

N10 X250.0 Y550.0 ;

Specifies machining from P9 to P1.

N11 G00 G40 X0 Y0 ;

Cancels the offset mode.

The tool is returned to the start position (X0, Y0, Z0).

300

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

This section provides a detailed explanation of the movement of the tool

14.6

for cutter compensation C outlined in Section 14.5.

DETAILS OF CUTTER

This section consists of the following subsections:

COMPENSATION C

14.6.1

General

14.6.2 Tool Movement in Start-up

14.6.3 Tool Movement in Offset Mode

14.6.4 Tool Movement in Offset Mode Cancel

14.6.5 Interference Check

14.6.6 Over cutting by Cutter Compensation

14.6.7

Input command from MDI

14.6.8

G53,G28,G30 and G29 commands in cutter

compensation C mode

14.6.9

Corner Circular Interpolation (G39)

14.6.1

General

D Inner side and outer side

When an angle of intersection created by tool paths specified with move

commands for two blocks is over 180°, it is referred to as “inner side.”

When the angle is between 0° and 180°, it is referred to as “outer side.”

Inner side

Outer side

Programmed path

Workpiece

Programmed path

180°xα

0°xα<180°

D Meaning of symbols

The following symbols are used in subsequent figures:

- S indicates a position at which a single block is executed once.

- SS indicates a position at which a single block is executed twice.

- SSS indicates a position at which a single block is executed three times.

- L indicates that the tool moves along a straight line.

- C indicates that the tool moves along an arc.

- r indicates the cutter compensation value.

- An intersection is a position at which the programmed paths of two

blocks intersect with each other after they are shifted by r.

- indicates the center of the tool.

301

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

14.6.2

When the offset cancel mode is changed to offset mode, the tool moves

as illustrated below (start-up):

Tool Movement in

Start-up

Explanations

D Tool movement around

an inner side of a corner

Linear→Linear

(180°xα)

Workpiece

Programmed path

G42

Tool center path

Start position

Linear→Circular

Work-

G42

piece

Start

position

Tool center path

302

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

D Tool movement around

Tool path in start-up has two types A and B, and they are selected by

the outside of a corner at

parameter SUP (No. 5003#0).

an obtuse angle

(90°xα<180°)

Linear→Linear

Start position

G42

Workpiece

Programmed path

Tool center path

Type

Linear→Circular

Start position

G42

Work-

piece

Tool center path

Programmed path

Linear→Linear

Start position

G42

Workpiece

Programmed path

Tool center path

Intersection

Type

Linear→Circular

Start position

G42

Work-

piece

Intersection

Tool center path

Programmed path

303

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

D Tool movement around

Tool path in start-up has two types A and B, and they are selected by

the outside of an acute

parameter SUP (No.5003#0).

angle (α<90°)

Linear→Linear

Start position

G42

Workpiece

α L

Programmed path

Tool center path

Type

Linear→Circular

Start position

G42

Work-

piece

Tool center path

Programmed path

Linear→Linear

Start position

G42

Workpiece

Programmed path

Tool center path

Type

Linear→Circular

Start position

G42

Work-

piece

Tool center path

Programmed path

D Tool movement around

the outside linear→linear

Tool center path

at an acute angle less

than 1 degree

(α<1°)

Programmed path

G41

Start position

Less than 1 deg

304

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

14.6.3

In the offset mode, the tool moves as illustrated below:

Tool Movement in

Offset Mode

Explanations

D Tool movement around

the inside of a corner

Linear→Linear

(180°xα)

Workpiece

Programmed path

Tool center path

Intersection

Linear→Circular

Work-

piece

Intersection

Programmed path

Tool center path

Circular→Linear

Workpiece

Programmed path

Tool center path

Intersection

Circular→Circular

Work-

Intersection

piece

Programmed path

Tool center path

306

14. COMPENSATION FUNCTION

PROGRAMMING

B-63534EN/02

D Tool movement around

the outside corner at an

Linear→Linear

obtuse angle

(90°xα<180°)

Workpiece

Programmed path

Intersection

Tool center path

Linear→Circular

Work-

piece

Intersection

Programmed path

Tool center path

Circular→Linear

Workpiece

Programmed path

IntersectionSL

Tool center path

Circular→Circular

Programmed path

Work-

piece

Tool center path

Intersection

308

PROGRAMMING

14. COMPENSATION FUNCTION

B-63534EN/02

D Tool movement around

the outside corner at an

acute angle

Linear→Linear

(α<90°)

Workpiece

Programmed path

Tool center path

Linear→Circular

Work-

piece

Programmed path

Tool center path

Circular→Linear

Workpiece

Programmed path

Tool center path

Circular→Circular

Work-

piece

Tool center path Programmed path

309

FANUC Series 16i/160i/160is-MB, Series 18i/180i/180is-MB5, Series 18i/180i/180is-MB. Operator's Manual - page 11