Laser Sheet Cutting
Laser sheet cutting uses a focused laser beam to melt, burn, or vaporise sheet material along a programmed path.
Laser Sheet Cutting uses a laser beam to cut sheet metal into the required shape. It is the most common cutting method for sheet metal parts in WSi and is typically the first operation applied to a Sheet node.
Laser Sheet Cutting is an automatic workstep — it runs automatically after the Sheet node is created during import. WSi creates the Laser Sheet Cutting node as part of the import workflow.
When to use this process
Laser Sheet Cutting is available automatically when:
- You import a DXF or GEO file as a sheet metal part
- You create a rectangular sheet using File → Create → Create rectangular cut
- You need to cut a flat sheet into a specific shape
WSi also supports plasma and waterjet cutting; laser is the default and most widely used.
Editing Laser Sheet Cutting Parameters
To change the nesting mode after the node is created, right-click the Laser Sheet Cutting node in the Graph View and select Edit Nesting Mode.
You can also edit deburring parameters and engraving settings from the same context menu:
Deburring Parameters — right-click → Edit Deburring Parameters to configure deburring speed and pass count. Deburring is typically applied after laser cutting to remove sharp edges from cut contours.
Engraving Config — right-click → Edit Engraving Config to set laser engraving speed and power for marking operations. Engraving uses the same laser source as cutting but at different power/speed settings.
TIP
Engraving and deburring parameters are also accessible from the Details panel when a Laser Sheet Cutting node is selected.
2D rep rotations
The 2D representation of a part — the flat drawing shown in the Graph View and exported in 2D files like DXF — can be rotated to a specific orientation. Right-click the Laser Sheet Cutting node and select Edit 2D Rep Rotations to set the rotation.
The dialog offers two settings:
- Rotation — the angle at which the 2D representation is displayed: 0°, 90°, 180°, or 270°. The correct orientation depends on how your downstream CNC equipment expects the drawing.
- Fixed rotations — a preset configuration that applies a predefined set of rotation steps. Select a preset from the list, or leave it on the default.
The 2D rep rotation setting affects the orientation of DXF and SVG exports from this node, the display of the part thumbnail in the Graph View, and any 2D output files generated from this workstep.
TIP
If your exported DXF files appear upside-down or at a wrong angle in your CAM software, adjust the 2D Rep Rotation on the relevant Sheet Cutting node before exporting.
Result
After Laser Sheet Cutting runs:
- A Sheet Cutting node appears in the Graph View, connected from the Sheet node
- The Tree View shows the cutting parameters and results (contour count, scrap, utilisation)
- Cut geometry is available as output for the next process (typically Bending)
WARNING
If the cut parts do not fit on the sheet in Actual nesting mode, WSi shows an error. Switch to Virtual nesting or adjust the sheet dimensions.
Parameters
The parameters for this process are configured in the database — see the Sheet cutting page.
Technical Background
A focused laser beam — generated by a CO₂ or fiber laser source — is directed at the metal surface through a system of mirrors or a flexible optical fiber and a focusing lens. The beam is concentrated to a very small spot, typically 0.1–0.5 mm in diameter, delivering extremely high power density.
The metal surface absorbs the laser radiation, rapidly heating the material to its melting point. Simultaneously, a jet of assist gas — oxygen or nitrogen — is coaxially blown through the welding nozzle onto the cut zone. The gas serves two purposes: it blows the molten material out of the narrow cut kerf, and it participates chemically in the cutting process.
When oxygen is used on mild steel, the exothermic reaction between the oxygen and the hot steel releases additional heat energy, significantly accelerating the cut. This is why oxygen cutting is faster on carbon steel. Nitrogen, by contrast, is chemically inert — it produces a clean, oxide-free edge that requires no post-processing. Nitrogen is the preferred gas for stainless steel and aluminium.
Because the laser beam does not physically touch the workpiece, there is no tool wear on the cutting element itself during the cut. The CNC system moves the laser head along the programmed contour, following the 2D geometry.
Cut quality — including surface roughness, presence of dross on the bottom edge, and the width of the heat-affected zone — depends on the combination of laser power, cutting speed, gas pressure, and standoff height (the distance between the nozzle and the workpiece). These parameters are stored in the database and mapped to material, gas, and thickness combinations.