G78 Rough Contour Example (G78UnFnPn)
See also G74: Box Roughing and G75: Box Contour Roughing

The Rough Contour cycle starts at the current position, then makes a cutting pass parallel to the final contour, but away from the part at a distance Un. At the end of the cycle, the tool is returned to the start point.

The location of the contour code:

• If the P code is present, the contour is defined in a subroutine.
• If the P code is not present, the contour is defined in the following blocks until a block with an "RF" code is encountered.

Worked external example for G78

Above is a part that can be roughed. The code that can be used to generate the contour could be: The program code for the contour can be placed immediately after the G78 (inline as shown above) or it can be placed in a sub-routine.