Fill Mode
Fill Mode tells your laser to etch parallel lines within the boundaries of vector graphics.
The distance between each line is determined by the Line Interval setting, and the Speed and Power settings control the darkness or depth of the etch. Use low Intervals, low Speeds, and high Powers for deep engravings or dark marks, or tell your laser to move quickly at low Power to lightly etch or mark the surface.
If you have two shapes set to the same layer, and one is inside of the other, the area between the two outlines will be filled.
Fill Mode Settings¶
There are several specialized options available in the Cut Settings Editor for layers set to Fill 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 specific kinds of lasers, but most are shared between all types of lasers.
Right: Advanced Fill Mode settings tab
Common Settings¶
Bi-directional Fill¶
When enabled, the laser will engrave in a side-to-side sweeping motion with the laser on and engraving in both directions.
When disabled, the laser will engrave while traveling in one direction, then return to the start of the next line without engraving the return pass. Depending on the type of laser, enabling this can save significant time on long engraving jobs.
Bi-directional vs. Uni-directional Fill Comparison
Cross-Hatch¶
When enabled, the laser will run a second engraving pass 90 degrees rotated from the first, to ensure a consistent and thorough fill.
Cross-Hatch Demonstration
Overscanning¶
Note
This switch is not available for DSP controllers or Galvo lasers. DSP controllers handle Overscanning automatically, while Galvo lasers compensate for extra burning at edges with Delay settings.
When enabled, adds extra moves to the beginning and end of each line to give the laser time to speed up before firing, and slow down afterward. Overscanning distance is calculated as a percentage of Speed.
When Overscanning is not used or not set correctly, engraved jobs appear more burned at the edges and lighter in the middle, due to the laser slowing down to change scanning direction, while firing.
LightBurn can compensate for this by running the laser head outside the boundaries of the engraving, but with the laser off. This maintains an even speed on the engraving itself to provide a consistent engrave. You need a little more space on either side of the engraving to accommodate this Overscanning.
Excessive Overscanning: GCode
If Overscanning is enabled on a GCode laser and there isn't enough room at the edge of the job to accommodate the extra travel distance, you may see LightBurn's Cut May Be Out Of Bounds error, or your laser's controller may return an ALARM:2 error.
To correct the error, reduce Speed or Overscanning distance, or move your graphics in toward the center of your Workspace, if you are using Absolute Coordinates positioning. If you are using Current Position or User Origin to set a custom Origin, set it closer to the center of your laser's work area.
Excessive Overscanning: DSP
DSP controllers handle Overscanning in hardware, but the Speed value you enter affects the amount of distance required. If a job on a DSP laser requires Overscanning and there isn't enough room at the edge of the job to accommodate it, your DSP controller may return the Not Enough Extend Space error.
To correct the error, reduce Speed or move your graphics in toward the center of your Workspace, if you are using Absolute Coordinates positioning. If you are using Current Position or User Origin to set a custom Origin, set it closer to the center of your laser's work area.
Overscanning Demonstration
Line Interval¶
Controls the spacing between scanned lines, and indirectly controls Lines per Inch.
Optimizing Line Interval
Lower Line Interval values lead to a greater density of lines. The ideal Line Interval will produce lines that just touch, without overlapping.
Increasing Line Interval to the maximum amount that doesn't leave gaps between lines will lead to reduced runtimes for your projects, with no loss in quality, but you may also need to increase Power to achieve dark engravings.
Use the Interval Test or Material Test to find the optimal Line Interval for your laser and material.
Lines Per Inch¶
A different, often more intuitive way of controlling the Line Interval, or spacing between rows.
Scan Angle¶
Scan Angle defaults to 0, meaning the laser will scan back and forth horizontally across the image, progressing from the bottom of the image to the top. If you set this to 180, the laser will scan the image from top to bottom. Setting this to 90 will scan the laser vertically over the image, progressing from left to right.
DSP Scan Angle Warning
If you have a DSP controller, we advise only using scan angles that are a multiple of 90 degrees. Horizontal and Vertical scanning is supported natively by the hardware, and it will automatically handle Overscanning beyond the sides of the image to get the head to full speed before engraving starts. Scanning at non-90 degree angles is "emulated" using normal cutting moves. It works, but it's mostly useful as a style option, and not recommended for general use.
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,
Fill Grouping¶
These options control which shapes are engraved at the same time by the laser. If you run your laser fast, or your laser accelerates slowly, it is often most efficient to scan things all at once, so the laser spends most of its time moving at the speed you've chosen, and less time changing direction. If you are engraving slowly, your laser accelerates fast, or the design contains a lot of blank space, it can be more efficient to fill clusters of close shapes, or to fill the shapes one by one.
Tip
If you aren't sure, try different options and use Preview to estimate the time.
- Fill all shapes at once: the default, this setting means that everything on this layer will be filled at the same time, sweeping back and forth across the whole job. If you are running the laser fast (300 mm/sec or more) this is usually the most efficient option, with some exceptions.
- Fill groups together: this setting will fill all shapes in a Group at the same time.
- Fill shapes individually: this setting fills all shapes one by one.
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.
Ramp Length¶
Use this setting to slope the sides of an engraving by varying the laser power. The ramp length controls how far from the design the slope will extend.
This setting is useful if you create rubber stamps, particularly if the designs have thin regions that need extra support.
Enable Ramp Outer Edge to slope the outer sides of an engraving, and not just the inner sides (it's usually best to leave this setting disabled for stamp-making).
Note
On a DSP controller, the Ramp varies the laser power from Min Power to Max Power, so you must set these differently to get a ramped side. Typically, you should set Min Power to be just above the firing threshold of your laser.
Flood Fill¶
Flood Fill calculates an engraving path that attempts to reduce or eliminate travel moves across blank space. It's useful for engraving things like large, empty rectangles, where the blank area in the middle would consume most of the time spent.
For Galvo lasers, Flood Fill is presented in the Common settings tab.
Warning
Flood Fill is very sensitive to machine tuning and backlash, and can cause gaps in your engraving if the design is too complex and/or your machine is not set up optimally. Use it sparingly, and use Preview to see how the option will engrave your design, so you aren't surprised by the path it takes.
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.
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.