Automatic tool liftoff with FUNCTION LIFTOFF

Application

The tool retracts from the contour by up to 2 mm. The control calculates the lift off 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 lift-off 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 can program the LIFTOFF function in the following ways:
  • FUNCTION LIFTOFF TCS X Y Z: Lift-off in the tool coordinate system (T-CS) with the vector resulting from X, Y and Z
  • FUNCTION LIFTOFF ANGLE TCS SPB: Lift-off in the tool coordinate system (T-CS) with a defined spatial angle
  • This makes sense for turning (option 50)

  • 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.

FUNCTION LIFTOFF in turning mode (option 50)

 
Notice
Caution: Danger to the tool and workpiece!
Undesired movements of the axes can occur if you use the FUNCTION LIFTOFF ANGLE TCS function in turning mode. The behavior of the control depends on the kinematics description and Cycle 800 (Q498 = 1).
  1. Carefully test the NC program or program section in Program run, single block operating mode.
  2. If necessary, change the algebraic sign of the defined angle

If parameter Q498 has been set to 1, the control will reverse the tool for machining.

  • In conjunction with the LIFTOFF function, the control behaves as follows:
  • If the tool spindle has been defined as an axis, the LIFTOFF direction will be reversed.
  • If the tool spindle has been defined as a kinematic transformation, the LIFTOFF direction will not be reversed.

Cycle 800 ADJUST XZ SYSTEM

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

; Lift off with the defined vector upon NC stop or power failure

12 FUNCTION LIFTOFF ANGLE TCS SPB+20

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

To navigate to this function:

Insert NC function All functions Special functions Functions FUNCTION 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 lifts off in the direction of the active tool axis.

Notes

  • The control uses the M149 function to deactivate the FUNCTION LIFTOFF function without resetting the lift-off direction. If you program M148, the control will activate the automatic lift-off of the tool in the lift-off direction defined by the FUNCTION LIFTOFF function.
  • In case of an emergency stop, the control will not lift off the tool.
  • The lift-off movement will not be monitored by Dynamic Collision Monitoring (DCM, option 40)
  • Dynamic Collision Monitoring (DCM, option 40)

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