Laser cutting

Laser cutting operation

Programming a toolpath for laser cut basically generates a cutting cycle, i.e. an operation, that consists of three sections:

approach (off-process)

cutting process (in-process)

retraction (off-process)

The cutting cycle is calculated and controlled by the programming attributes and events.

Cutting cycles

Besides having the global programming attributes and events determining the calculated toolpath, there are some additional features and routines that can be applied for maximum optimization, efficiency and performance of the laser cut cycle.

Regular shapes	Geometrical base contours, like circles, rectangles, triangles and such are programmed with predefined cycles for that particular base shape. These cycles may overrule some other attributes.
Process orientation	Works only in situations where an 1- or 2-rotary axis positioner carries the workpiece and the positioner (motion) is connected to the controller. On each toolpath position the positioner axis are manipulated in such way that the laser head is kept in a predefined (usually down-) position. As an example this predefined position is for security reasons to have the laser beam always pointing down.
Side tangent	Contour cutting cycle, where the cutting direction is determined by the tangent surface.

Tool angles

In general there are three tool angles to define the laser head orientation starting from its nominal position.

Work	Travel	Tool

Tool alignment

Each tool has a tool frame that is used to place it at the toolpath in its correct position and orientation. It is essential that this frame has been aligned with the orientation of the process geometry in order to get a correct result. This alignment is the mapping between the tool frame and the process geometry.

When creating the process geometry, a normal direction (purple arrows) and tangent or travel direction (red arrow) have been defined.

With the Alignment attributes, the tool frame axes have to be mapped with these directions

Programming attributes

The display of the programming attributes in the Programming defaults and Active program dashboards is defined in a Settings.xml file. With a standard installation, a default file is located at the path <install>\E2Plugin\Technologies\LaserCuttingTechnology\Standard\ControllerSettings.

For the standard controller the following attributes are defined.

Tech tab	Container	Attribute	Description
Program base
Tool data
Manufacturing geometry
Toolpath calculation
Technology base
Contour
Regular shape
Tangential cutting
Operation linking
For automatic link path generation
Toolpath quality
Automatic path optimization

	The program reference information.
Base frame	The reference frame of the program.

	Tool information.
Tool resource	The name of the tool.
Technology	The applied technology.
Automatic tool change
Tool frame	The tool frame that runs the toolpath.

	The mapping of the tool frame axes with the corresponding vectors on the process geometry.
Normal direction	The alignment of the tool frame Z axis with the normal direction of the process geometry.
Tangent direction	The alignment of the tool frame X axis with the tangent direction of the process geometry.

	The global transformation of the manufacturing geometry.
Translation in X,Y,Z	The global translation in X,Y or Z direction.
Rotation around X,Y,Z	The global rotation around the X,Y or Z axis.

	The boundary conditions on the manufacturing geometry to calculate the toolpath.
Distance start point	The distance of the first in-process point from the process geometry start position.
Distance end point	The distance of the last in-process point to the process geometry end position.
Opposite approach side	To reverse the approach side at the manufacturing start position.
Reverse process direction	To reverse the manufacturing process direction, i.e. changes start to end position and vice verse.

	The approximation of the manufacturing contour to calculate the toolpath.
Mode	The mode to approximate the contour.
Max. sag	The maximum allowed deviation between the geometry and calculated toolpath.
Max. distance	The maximum distance between two in-process toolpath elements along the contour.
Event relink tolerance	The tolerance to find the nearest TPE after a toolpath re-computation, to assign the existing event to. This attribute is hidden by default.

	The offset of the toolpath element from its original location on the manufacturing geometry.
Contour offset	The offset in bi-tangent direction.
Sheet offset	The offset in (surface) normal direction.

	Machine singularity attributes that are applied when calculating the toolpath, i.e. the algorithms are applied before any further manual enhancement, like teach.
Enforce singularity	Enforced singularity optimization of the A and B axis (also named C and A axis) of an NC machine.
Deviation cone	Axis with values within the specified cone angle are being optimized.
Fixed axis control	Method how both axis are being optimized.

	Laser cutting recipes.
Use regshape	Switch to convert (closed) contours in predefined regular shapes, like circles, rectangles, hexagons, etc.

	Additional (optimization) conditions to calculate the toolpath.
Process orientation	A switch to optimize each toolpath element with use of the positioner axis to maintain the tool axes in down-hand direction. The condition is only available when a 1-2 axis positioner, carrying the workpiece, is connected to the controller.
Ext. axis backprop. (External axis values in approach)	The axis values of an external resource, like a positioner, as been set at the first position of the in-process path, will be propagated backwards up to the approach of that in-process path.
CTS backpropagation	The configuration, turn and singularity state of the manufacturing resource, like a laser machine, as been set at the first position of the in-process path, will be propagated backwards up to the approach of that in-process path.

	The overrun (extrapolation) at the contour end when programming an operation.
Overrun	The value of the overrun length. A negative value is possible.
Keep original point	Switch to define if the original path element (position) is being moved to the overrun position or remains at its original position. In the last case a new path element is created at the overrun position.

	To define an approach motion towards the in-process toolpath.
Approach	The number of approach steps.
Motion	The motion type for the approach.
Offset reference	The reference to determine the offset directions.
Offset tangential / bitangential / normal	The local offset of the approach step from the in-process toolpath start element.

	To define a retraction motion away from the in-process toolpath.
Retract	The number of retraction steps.
Speed	The velocity of the retract.
Flyby	Allow the motion to make use of the flyby accuracy (On distance) or force the motion to the retract position (Off).
Flyby distance	The motion accuracy on the retract path.
Offset tangential / bitangential / normal	To local offset of the retract step from the in-process toolpath end element.

	To define an approach motion towards the in-process toolpath.
Approach rule	The predefined approach.

	To define a retraction motion away from the in-process toolpath.
Retract rule	The predefined retraction motion.

	The definition of the tangential cutting.
Cutting strategy	The strategy to compute the side tangent toolpath.
Tool radius	The number of stitch seams..
Maximum angle step	The maximum allowed change of the tool angles along the computed toolpath.
Minimize rotation	Switch to activate the computation with minimum tool angle rotation.
Cutting speed	The velocity along the toolpath..

	To define an approach motion towards the in-process toolpath.
Approach	The number of steps or method of approach.
Final motion type	The motion type for the approach step to the in-process start position.
Approach radius	The radius of the above approach step. Applies when the Final motion type is circular.
Offset tangential / bitangential / normal	To local offset of the approach step(s) from the in-process toolpath start element.

	To define a retraction motion away from the in-process toolpath.
Retract rule	The number of steps or method of retraction.
Offset tangential / bitangential / normal	To local offset of the retract step from the in-process toolpath end element.
Feedrate to retract	The velocity of the retraction step.

	The way how to move to the next operation.
Link type	The motion type to link the operations.
Circular height	The height of the via point to calculate a circular link.

	The way how to move to the next operation for automatic link path generation.
Link type	The motion type has been set to Automatic linking.
Motion	The motion type along the path.
Collision tolerance	Defines the safety distance when generating the link path.
Unlock external axis	Use of the entire range of the external axis values for the link path generation. Off: The external axis value can only be changed within the interval given by start and end point of the link path. On: The external axis values are to be considered within the full range of each axis (i.e. are unlocked).
Max. #iterations	Defines the maximum number of iterations that the path finding algorithm will run.

	The way how to move to the next operation. Only valid for automatic link path generation.
Speed mode	The motion speed.
Speed value	The speed value of the motion.
Flyby mode	The flyby motion, i.e. the accuracy to move along the link path positions.
Flyby value	The value of the flyby accuracy (when applicable).

	The toolpath quality evaluation criteria. The exact content may vary per technology.
Unreachability	Evaluates unreachable situations of the robot or machine.
Collision	Evaluates collision situations.
Singularity	Evaluates singularity situations of the robot or machine.
Process angle deviation	Evaluates the process angle deviation from its reference value.
Axis limit proximity	Evaluates the proximity to the limits of the driven axis. Separated evaluation value range for linear and circular joint axis.
Axis speed	Evaluates the axis speed of all driven axis as a (absolute) difference between the start and the end motion between positions.

	The automatic path optimization parameters.
Variation space	Defines what modifications can be made to the toolpath elements to search for the optimal solution, i.e. minimal costs.
Optimization control	Attributes to manage the optimization process.

Program events

The generic arc welding technology has the following programming events:

Motion events
Speed	Sets the velocity for the subsequent motions.
Accuracy	Sets the accuracy for the subsequent motions.
Dwell	Sets a waiting time at the path element for the tool to remain position until moving further.
Acceleration	Sets the acceleration for the subsequent motions.

IO signal events
Wait for signal	Adds a wait for an input signal event of the active controller.
Set signal	Adds a set output signal event of the active controller.
Synchronize robots	Sets an event to synchronize cooperating robots.
Set resource port	Sets a port of a resource.
Wait for resource port	Waits for a port of a resource.
Adapter actor	Sets a signal of a mechanical parent adapter to create or delete a mechanical connection during simulation.

Technology event
Text	Inserts a comment.

Laser on	Powers on the laser beam.
Laser off	Powers off the laser beam.
Inspection data	Sets an inspection position.
Micro tab	Builds a micro tab at the position.

Auxiliary commands

The default arc welding technology delivers a few auxiliary commands that can be executed on the program id, as listed in the Program manager dashboard.

More information