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There are multiple articles/cnc program examples about G code circular interpolation, here is the list of few articles so that cnc machinists can easily navigate through different cnc programming articles.


Manual Part Programming

 

Lathe

 

G02 G03 G Code Circular Interpolation

 

G02 G Code Clock wise Circular Interpolation.

 

G03 G Code Counter Clock wise Circular Interpolation.

 

There are multiple articles/cnc program examples about G code circular interpolation, here is the list of few articles so that cnc machinists can easily navigate through different cnc programming articles.

 

G02 G03 G Code Example CNC Programs (G code Arc Examples) o CNC Circular Interpolation Tutorial G02 G03

o  Fanuc CNC Lathe Programming Example

 

o CNC Programming Example G Code G02 Circular Interpolation Clockwise o Fanuc G20 Measuring in Inches with CNC Program Example

o  CNC Arc Programming Exercise

 

o CNC Programming for Beginners a CNC Programming Example o CNC Lathe Programming Example

 

Here is a new CNC programming examples which shows the use of G02 G03 G code circular interpolation.

 

G02 G03 G Code Example Program



G02 G03 G Code Circular Interpolation Example Program


N20 G50 S2000 T0300

G96 S200 M03


G42 G00 X35.0 Z5.0 T0303 M08

G01 Z-20.0 F0.2

G02 X67.0 Z-36.0 R16.0

G01 X68.0 :

G03 X100.0 Z-52.0 R16.0

G01 Z-82.0

G40 G00 X200.0 Z200.0 M09 T0300


M30



G Code G02 G03 I & K Example Program

 

G02 G03 G Code Circular Interpolation can be programmed in two ways,


G02 X... Z... R...


G02 X... Z... I... K...


The below is the same cnc program but this version uses I & K with G02 G03 G code.

N20 G50 S2000 T0300
G96 S200 M03

G42 G00 X35.0 Z5.0 T0303 M08
G01 Z-20.0 F0.2
G02 X67.0 Z-36.0 I16.0 K0
G01 X68.0 :
G03 X100.0 Z-52.0 I0 K-16.0
G01 Z-82.0

G40 G00 X200.0 Z200.0 M09 T0300
M30


G20 Turning Cycle Format for Straight Turning

G20 X Z F…

or

 

G20 U… W… F…

 

X Diameter to be cut (absolute).

Z End point in z-axis (absolute).

F Feed-rate.

 

U Diameter to be cut (incremental).

 

W End point in z-axis (incremental).




G20 Turning Cycle CNC Lathe Fanuc 21 TB

G20 Turning Cycle Format for Taper Turning

 

G20 X Z… R… F…

or

G20 U… W… R… F…

 

X Diameter to be cut (absolute).

Z End point in z-axis (absolute).

R Incremental taper dimension in X with direction (+/-)

F Feed-rate.

U Diameter to be cut (incremental).

 

W End point in z-axis (incremental).

 

As cnc machinists can use X or U value for the contour value, same way Z or W can be used or you can even mix both absolute (X, Z) and incremental (U, W) values.

 

G20 Turning Cycle Example CNC Program Code

G96 S200 M03

G00 X56.0 Z2.0

 

G20 X51.0 W-20.0 F0.25

X46.0

X41.0

X36.0

X31.0

X30.0

G00 X100 Z100

 

M30

 

CNC Program Code Explanation

 

As you can see in the above cnc program code, Tool is at X56 Z2 point,

 

First cut is made at X51 and tool travels W-20 in Z-axis. Second cut is made at X46

Third cut is made at X41

 

Last cut is made at X30

 

G20 Turning Cycle Function

 

 As if you study the above cnc program code you will notice that, 1  with G20 both absolute (X51.0) and incremental (W-20.0) values are used to make cuts. 2  If above code also shows a very powerful functionality of G20 turning cycle which is that a cnc machinist can control depth-of-cut of every pass of G20 turning cycle which is impossible to achieve with other Turning Canned Cycle like G71 Rough Turning Cycle. So you will notice first five-cuts are of 5mm deep but the last one is just 1mm deep.



Cancellation of G20 Turning Cycle

 

G20 turning cycle is a modal G-code.

“Modal” G-code meaning that they stay in effect until they are cancelled or replaced by a contradictory G code.


It means G20 turning cycle remains active until another motion command is given like G00, G01 etc. As in above cnc program example G20 G code is cancelled with G00 G code.

 

 

Milling

 

Programming

G72.1 P... L... X... Y... R...


Parameters

Parameter Description

P Subprogram number

L Number of times the operation is repeated

X Center of rotation on the X axis

Y Center of rotation on Y axis

R Angular  displacement  (a  positive  value  indicates a  counter  clockwise angular displacement. Specify an incremental value.)

 

G-Code Data

Modal/Non-Modal : G-Code Group

Non-Modal : 00

 

Programming Notes

Notes

1.    In the G72.1 block, addresses other than P, L, X, Y and R are ignored.

2.    P, X, Y and R must always be specified.

3.    If L is not specified, the figure is copied once.

 

4.    The coordinate of the center of rotation is handled as an absolute value even if it is specified in the incremental mode.

 

5.    Specify an increment in the angular displacement at address R. The angular displacement (degree) for the Nth figure is calculated as follows: Rx(N-1).

 

First block of the subprogram

 

Always specify a move command in the first block of a subprogram that performs a rotational copy. If the first block contains only the program number such as O00001234; and

 

does not have a move command, movement may stop at the start point of the figure made by the n-th (n = 1,2, 3, …) copying.


Example of an incorrect program


O00001234 ;

G00 G90 X100.0 Y200.0 ;


;

;


M99 ;

Example of a correct program


O00001000 G00 G90 X100.0 Y200.0 ;

;

;


M99 ;


Limitation

Specifying two or more commands to copy a figure

 

G72.1 cannot be specified more than once in a subprogram for making a rotational copy (If this is attempted, alarmPS0900 will occur).

 

In a subprogram that specifies rotational copy, however, linear copy (G72.2) can

 

be specified. Similarly, in a subprogram that specifies linear copy, rotational copy can be specified.

 

Commands that must not be specified Within a program that performs a rotational copy, the following must not be specified: Command for changing the selected plane (G17 to G19) Command for specifying polar coordinates (G16)

Reference position return command(G28) Axis switching

Coordinate system rotation (G68) scaling (G51)

programmable mirror image (G51.1)

The command for rotational copying can be specified after a command for coordinate system rotation, scaling, or programm able mirror image is executed.

 

 

Single block

Single-block stops are not performed in a block with G721.1 or G72.2.

 

 

G72.1 Programming Example


Main program

O1000 ;                         

N10 G90 G00 X80. Y100. ;                       (P1)

N20 Y50. ;  ( P2) 

N30 G01 G17 G42 X43.301             Y25. D01 F100 ;(P3)

N40 G72.1 P1100 L3 X0 Y0  R120. ;

N50 G90 G40 G01 X80. Y50 . ;       (P2)

N60 G00 X80. Y100. ;                     (P1)

N70 M30 ;                    

O1100 G91 G03 X-18.301 Y18.301 R50. ; (P4)

N100

G01   X-5.   Y50. ;         (P5)

N200 G03   X-40. I-20. ;         (P6)

N300 G01   X-5.   Y-50. ;        (P7)

N400 G03   X-18.301 Y-18.301 R50. ;   (P8)

 

N500 M99 ;


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