In this article, we write CNC program example for rotational and linear copy commands (G72.1 and G72.2 codes) in CNC Milling machines.
Programming Notes
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, alarm PS0900 will occur).
- G72.2 cannot be specified more than once in a subprogram for making a linear copy (If this is attempted, alarm PS0901 will occur).
- In a subprogram that specifies rotational copy, however, linear copy can be specified. Similarly, in a subprogram that specifies linear copy, rotational copy can be specified.
Technical Drawing
Fanuc G72.1 G72.2 Figure Copy Program Example (Bolt Hole Circle)
CNC Program
Main program
O4000 ;
N10 G90 G00 G17 X240. Y230. Z100. ; (P0)
N20 G72.1 P4100 X120. Y120. L8 R45. ;
N30 G80 G00 X240. Y230. ; (P0)
N40 M30 ;
Sub program – Rotation copy (G72.1)
O4100 N100 G72.2 P4200 I0 J20. L3 ;
N200 M99 ;
Sub program – Linear copy (G72.2)
O4200 N110 G90 G81 X120. Y180. R60. Z10. F200. ; (P1)
N210 M99 ;