Contour approach and departure

With the G26 and G27 NC functions, you can approach or depart the contour smoothly using a circle segment.

NC programs contained in this User's Manual are suggestions for solutions. The NC programs or individual NC blocks must be adapted before being used on a machine.

  • Change the following contents as needed:
  • Tools
  • Cutting parameters
  • Feed rates
  • Clearance height or safe position
  • Machine-specific positions, e.g. with M91
  • Paths of program calls

Some NC programs depend on the machine kinematics. Adapt these NC programs to your machine kinematics before the first test run.

In addition, test the NC programs using the simulation before the actual program run.

 
Tip

With a program test you determine whether the NC program can be used with the available software options, the active machine kinematics and the current machine configuration.

N110 G01 G40 G90 X-30 Y+50

; Starting point

N120 G01 G41 X+0 Y+50 F350

; First contour point

N130 G26 R5

; Tangential approach

* - ...

N210 G27 R5

; Tangential exit

N220 G00 G40 X-30 Y+50

; End point

HEIDENHAIN recommends the use of the more powerful APPR and DEP NC functions. In some cases, these NC functions combine multiple NC blocks for approaching and departing the contour.

G41 and G42 correspond to the RL and RR Klartext syntax.

Approach and departure functions with Cartesian coordinates

You can also use polar coordinates when programming the APPR and DEP NC functions.

Approach and departure functions with polar coordinates