Line Mode
Line Mode tells your laser to trace a path around the contours of vector graphics.
If you command the laser to move quickly, or with low Power, it will likely just etch the surface (sometimes called scoring). If you move slowly and with high power, especially with a CO2 laser, the laser will cut deeper, or even completely through the material. The only difference between surface marking and cutting with Line Mode is the Power and Speed you set.
Line Mode Settings¶
There are several specialized options available in the Cut Settings Editor for layers set to Line Mode, split into two tabs, Common and Advanced.
Note
See Main / Shared Settings for information on applying essential settings like Speed and Power.
See Additional Options for information on specialized settings not covered on this page.
Click any option in the images below to jump directly to the relevant section for that option, or scroll down for a list of options and descriptions.
Many of the settings presented in the images below are available for users with DSP lasers only, but most are shared between all types of lasers.
Right: Advanced Line Mode settings tab
Common Settings¶
Number of Passes¶
How many times the laser will repeat the shapes on this layer. Sometimes, when cutting thick material, trying to engrave very deep, or using a lower power laser, more than one pass may be necessary.
Z Offset¶
If you have Z movement enabled, and your controller supports it, you can use the Z offset setting to move the laser head closer to the material (inward) or farther away from it (outward). Positive values move the Z Axis inward, and negative values move it outward.
Focusing deeper into the material can sometimes help to cut thicker material, and lifting the laser away from the material can produce a thicker line.
Warning for Z Moves
Z moves have the potential to physically damage your laser by crashing the head into the material.
If your system uses auto-focus, you may not be able to push the focus point lower, because most systems treat the auto-focus height as the lowest possible height (Z limit) to avoid crashing the laser head.
Z Step per Pass¶
When doing more than a single pass over a shape, the Z step per pass setting allows you to tell LightBurn to raise or lower the laser with each pass by the same amount.
By allowing you to shift the focus point deeper with each pass, this is often useful for cutting thick materials or achieving deep engravings,
Kerf Offset¶
Closed Shapes Only
Because LightBurn must determine the inside and outside of a shape in order to apply a Kerf Offset, this setting will only work with closed shapes.
Kerf refers to the thickness or width of a cut made by a cutting tool. The kerf of a laser is much narrower than that of a saw blade, but the extra material removed can interfere with close-fitting parts such as tabbed boxes or inlays.
Kerf Offset compensates for the extra material removed by offsetting the path of the laser to the outside of closed shapes (for positive values) or the inside (for negative values). This doesn't modify the underlying shape, so you can use your design on lasers with different kerfs by adjusting the Kerf Offset value.
The image below shows how Kerf Offset (dashed lines) relates to the original shape (solid lines).
Perforation Mode¶
Enable Perforation Mode to specify a distance to Cut, followed by a distance to Skip.
As the laser traces the contours of shapes assigned to this layer, it will turn on over the specified Cut distance, and off over the specified Skip distance.
Perforation mode is useful if you're trying to cut fold lines in card stock, stitch holes in leather, or make dashed lines.
Use Perforation Mode to reduce effective power output
This can also help when using delicate materials with a powerful laser. With very low cut and skip values, the beam is rapidly switched on and off, reducing the effective power output. Try starting with cut and skip values of 0.1 mm each, and adjust the ratio between cut and skip to tune it further.
Tabs / Bridges¶
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.
See Add Tabs for information on creating and adjusting Tabs / Bridges settings.
Advanced Settings¶
Under the Advanced tab you'll find several less frequently-used options. Many of the options presented here are available only for particular types of lasers.
Note
The Advanced tab is not available if you're using a Galvo laser. See Galvo-Specific Cut Settings for information on advanced settings for Galvo lasers.
Start / End Pause Time¶
Use these options to add a delay, in milliseconds, at the beginning of a cut, the end, or both.
If you also enable the Cut Through option, the beam will be turned on during this pause, which can be used to prime the cut and help pierce through thick material. The Power % value sets the power of the laser during this pause.
Without the Cut Through toggle enabled, it can add a delay to let the gantry settle down after a rapid move, or allow time for an air assist solenoid to engage.
Note
This setting is not available for lasers with TopWisdom controllers. Dwelling without Cut Through enabled is not available for lasers with Trocen controllers.
Overcut¶
Enable Overcut to tell your laser to extend a cut by a specified amount past the end of closed shapes, on the final Pass.
Override PWM Frequency¶
If you have an RF Excited tube, this setting allows you to control the PWM frequency of the pulses sent to the laser, and can change the edge finish on certain materials.
Note
This setting is only available for lasers with Ruida controllers.
Enable PPI¶
The PPI setting (Pulses Per Inch) lets you tell the laser to send an exact number of pulses per inch of travel, instead of varying the beam power directly. This is useful for delicate materials like paper, and is similar to using Perforation Mode, but is handled by the hardware itself.
Note
This setting is only available for lasers with Trocen controllers.
Lead In / Lead Out¶
Lead-In and Lead-Out are optional lines or curves added to the start or end of a cut. You can toggle each on or off individually, and specify their Length, Angle and Style.
When cutting thick material, particularly if using Cut Through delays, or cutting metal, there is often a mark left at the start of the cut that is slightly thicker than the rest, and can leave an indent on an otherwise smooth edge. With this setting, you can add a small line to the start or end of a cut, so that mark happens off the cut line itself.
The Angle value controls the placement of the lead line — a positive number tells LightBurn to put the lead line outside the shape, and a negative number means to put it inside. You can choose to make the lead a straight Line, or a short Arc.
The shape above on the left is using an Arc set to +45 degrees, so it starts outside the shape. The one on the right is a Line set to -20 degrees, so it appears inside the shape.
Dot Mode¶
When enabled, the laser will pause and pulse at regular intervals along the path, instead of cutting continuously. The Time value specifies the pause delay in milliseconds, and the spacing parameter sets how far apart the pulses are.
This can be an effective way to do stitching holes, or cut very thin or delicate materials, but the constant pausing can shake the machine - using Perforation Mode is often preferable for this reason.
Note
This setting is only available for lasers with Ruida controllers.
U Offset¶
Enter a distance here to set a per-layer U Axis offset. To use this setting, your laser must support U Axis control, and you must enable the U Axis in Device Settings.
Note
This setting is only available for lasers with Ruida controllers.
Additional Options¶
The settings presented in the Cut Settings Editor depend on the selected Layer Mode and the type of laser you're working with. Select an option below to learn more about different groups of settings.
Note
Some options in the Cut Settings Editor are hidden if you have Beginner Mode enabled.
For more help using LightBurn, please visit our forum to talk with LightBurn staff and users, or email support.