Add Tabs

Tabs are small sections of cuts that the laser is commanded to skip, used to prevent objects that you are cutting from immediately falling out of the base material. When sized appropriately, the tabs can be broken with minimal force and the objects removed from the material after the job is finished cutting.

You can create tabs manually using the Add Tabs tool, or LightBurn can generate them automatically. Options controlling the size of Manual tabs, and spacing, number, and positioning of Automatic tabs, are available in the Cut Settings Editor.

In the example below, the left square has no tabs applied, while the right has a single 1 mm wide tab on each side.

Adding Tabs Manually

To manually add tabs, select Add Tabs from the Tools Toolbar (or press Ctrl / Cmd+Tab), then hover over a shape in your Workspace that's assigned to a layer set to Line Mode.

If you are hovering over a valid shape, you'll see the Insert Tab cursor (). Click to insert a tab at that location. A red dot will appear on the shape, indicating that the tab has been placed.

Click and drag the red dot to move its location on the shape, or even to another valid shape in your Workspace.

The default width of manually placed tabs is .5 mm. Tabs cannot be placed closer together than is allowed by their width. See the next section for information on adjusting tab width.

To remove an existing tab, double-click the red dot, or hold the Shift key while clicking it.

Automatic Tab Generation and Tab Settings

To adjust the settings for Manual tabs, or enable and adjust settings for Automatic tabs, double-click a layer set to Line Mode in the Cuts / Layers Window, to open the Cut Settings Editor.

Tab settings are available in the lower half of the Cut Settings Editor.

Global Enable / Disable

The switch next to Tabs / Bridges controls whether tabs are enabled for the layer. If you have manually added tabs to a shape, this will automatically be switched on for the layer the shape is assigned to.

Switch Tabs / Bridges off to disable tabs. Tab settings and placement are not lost when this switch is turned off, and are restored exactly as they were if it is switched on again.

Tab Generation

Manual: all tabs must be manually placed using the methods described above.
Automatic: tabs will be placed on shapes assigned to the layer, based on the values of Even Spacing, Tabs Per Shape, and Skip Inner Shapes.

Tab Size

This setting affects both Manual and Automatic tabs.

Tab Size defines the total length of all tabs, in the currently configured system unit type (mm or inch). The laser will skip cutting for this distance, if possible.

Even Spacing

With Even Spacing selected, each contiguous path section will have at least one tab applied at the very start of the path and then again at the distance interval set in the Spacing field.

Spacing is set in the currently configured system unit type (mm or inch).

Limit Max Tabs

Enable Limit Max Tabs to set an upper bound on how many tabs can be automatically generated for each path, when using Even Spacing.

Tabs Per Shape

Select the Tabs Per Shape option to specify the number of tabs to create on each path assigned to the layer. Tabs will be automatically spaced evenly along the path.

Tab Cut Power

This setting affects both Manual and Automatic tabs.

If Tab Cut Power is set to any value other than 0%, the laser will make pulsed cuts across the width of the tabs instead of skipping them completely.

Increasing the percentage increases the amount the laser pulses on during tabs, resulting in tabs that are more weakly connected to the base material.

In the example below, the top tab is set to 25%, while the bottom tab is set to 75%. The black lines represent areas along the path where the laser is on, and the red lines represent areas where the laser is off.

Skip Inner Shapes

When enabled, any shapes that are completely contained by another shape in the same cut layer will not have Automatic tabs applied. This does not affect Manual tab placement.

Warning

Containing shapes must be closed, continuous loops in order for LightBurn to identify shapes within them. See Open vs. Closed Shapes for more information.

Clear Tabs

Deletes all tabs (Manual or Automatic) from every shape on this cut layer.

Troubleshooting

Tabs functions are not available if you are using Beginner Mode. You can disable Beginner Mode in Settings/Preferences.

For more help using LightBurn, please visit our forum to talk with LightBurn staff and users, or email support.