Automatic tool liftoff with FUNCTION LIFTOFF

Application

The tool retracts from the contour by up to 2 mm. The control calculates the liftoff direction based on the input in the FUNCTION LIFTOFF block.

The LIFTOFF function is effective in the following situations:

  • In case of an NC stop triggered by you
  • In case of an NC stop triggered by the software (e.g., if an error has occurred in the drive system)
  • In case of a power interruption

Requirements

  • Function enabled by the machine manufacturer
  • In machine parameter on (no. 201401), the machine manufacturer defines whether automatic liftoff is active.

  • LIFTOFF activated for the tool
  • You must define the value Y in the LIFTOFF column of the tool management.

Description of function

You have the following options for programming the LIFTOFF function:

  • FUNCTION LIFTOFF TCS X Y Z: Liftoff in the tool coordinate system (T-CS) with the vector resulting from X, Y and Z
  • FUNCTION LIFTOFF ANGLE TCS SPB: Liftoff in the tool coordinate system (T-CS) with a defined spatial angle
  • FUNCTION LIFTOFF RESET: NC function reset

Tool coordinate system T-CS

The control automatically resets the FUNCTION LIFTOFF function at the end of a program.

Input

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.

11 FUNCTION LIFTOFF TCS X+0 Y+0.5 Z+0.5

; Liftoff with the defined vector upon NC stop or power failure

12 FUNCTION LIFTOFF ANGLE TCS SPB+20

; Liftoff with spatial angle SPB +20 upon NC stop or power failure

To navigate to this function:

Insert NC function All functions Special functions Functions Tool retraction LIFTOFF

The NC function includes the following syntax elements:

Syntax element

Meaning

FUNCTION LIFTOFF

Syntax initiator for an automatic liftoff

TCS, ANGLE or RESET

Define the liftoff direction as a vector or a spatial angle or reset liftoff

X, Y, Z

Vector components in the tool coordinate system T-CS

Only if TCS has been selected

SPB

Spatial angle in T-CS

Only if ANGLE has been selected

When entering 0, the control liftoff in the direction of the active tool axis.

Notes

  • The control uses the M149 function to deactivate the FUNCTION LIFTOFF function without resetting the liftoff direction. If you program M148, the control will automatically liftoff the tool in the direction defined by the FUNCTION LIFTOFF function.
  • In case of an emergency stop, the control will not liftoff the tool.
  • The liftoff movement will not be monitored by Dynamic Collision Monitoring (DCM) (#40 / #5-03-1)
  • Dynamic Collision Monitoring (DCM) (#40 / #5-03-1)

  • In machine parameter distance (no. 201402), the machine manufacturer defines the maximum liftoff height.
  • In machine parameter feed (no. 201405), the machine manufacturer defines the speed of liftoff movement.