First Material Test

Getting recommendations directly from your laser's manufacturer is usually the best option for finding cut settings, but if those recommendations aren't available or aren't yielding great results, there's another option.

LightBurn has a built-in Material Test that you can use to test different combinations of Speed, Power, Passes, Line Interval, and other settings. The Material Test works by automatically setting up a grid of boxes that will be cut or engraved at a range of different settings.

We'll walk you through the process of setting up a Material Test grid to test both engraving and cut settings.

What You'll Need¶

LightBurn installed on your computer.
A laser added to LightBurn.
A spare piece of material you want to test, placed in your laser's work area. Proper settings differ between materials, so you'll need to peform the test again if you change material.

Material Test Positioning¶

Note for Galvo laser users

Galvo lasers always use Absolute Coordinates positioning, and, by default, the test grid will output in the center of your laser's work area. You can adjust its location by using the nudge hotkeys while Framing, or manually changing the Y Center and X Center values in the Material Test Generator window.

The output location of the test grid in your laser's work area is determined by the Start From mode you select before opening the Material Test Generator window. If you choose Absolute Coords, you'll have additional controls within the Material Test Generator window, but we'll be using Current Position in this guide.

In the Start From drop down menu in the Laser Window, select Current Position.
In the 9-dot Job Origin selector beneath the drop down menu, select the center position.
Selecting Current Position and the center Job Origin location means the Material Test grid will be centered wherever the laser head is located when you press the Start button later on.

Click here to learn more about Current Postion and other Start From modes

With Current Position selected, your job outputs relative to wherever the laser head is located when you press the Start button. The Job Origin control in the Laser Window tells LightBurn how to orient output relative to the laser head.

In this image, we're starting from the Current Position, with the Job Origin set to the lower left:

Notice that the green Job Origin indicator is positioned to the lower left of our graphics. This represents the position of the laser when you start the job, so the laser is going to move slightly up and to the right from wherever it is, cut the four hexagons, and go back to where it started.

Now imagine that you want to etch this four hexagon pattern onto a coaster or a phone case. Lining it up from the lower left is not easy. If you change the Job Origin setting to center, you get this instead:

The job will be centered around the current position of the laser head. If you position the laser head directly over the center of the item you want to etch, the output will be centered on the item.
Jog your laser over the material. Make sure there is enough room around your laser's head to accomodate an approximately 80 mm x 95 mm rectangle — the default size of the Material Test grid.

If your laser has a controller display and keypad, you can use the buttons there to jog. If not, use the buttons in the Move Window.

Click here to learn more about jogging your laser

LightBurn has a few tools for adjusting the location of your laser's head within its work area — the most straightfoward option for beginners is to use the arrow keys in the Move Window. By default, the Move Window is hidden behind the Cuts / Layers Window — click the Move tab to expose it.

The arrow keys move your laser up, down, right, or left. You can set the amount the laser travels with each click in the Distance field, and the rate at which it travels in the Speed field.

Focusing the Laser¶

Lasers need to be focused correctly to achieve good results.

Place the material in the laser and move the head over the material. LightBurn has jog controls in the Move Window to make this easier. You can ignore this step if you've got a Galvo laser.

Click here to learn more about jogging your laser

LightBurn has a few tools for adjusting the location of your laser's head within its work area — the most straightfoward option for beginners is to use the arrow keys in the Move Window. By default, the Move Window is hidden behind the Cuts / Layers Window — click the Move tab to expose it.

The arrow keys move your laser up, down, right, or left. You can set the amount the laser travels with each click in the Distance field, and the rate at which it travels in the Speed field.
Focus the laser according to your laser's user guide:
- GCode-based Diode lasers usually have a focusing spacer to set the distance between the laser and the material.
- DSP-type CO₂ lasers may require manual focusing with a focusing spacer or may support auto-focus, either through the controller, or with the Focus Z button.
- Galvo lasers require manual focusing. Many galvo lenses are marked with their optimal focal distance, and you can use a ruler to set the correct distane between the lens (or mirrors) and your material. Some are equipped with a two red dot focusing system — adjust the height of the scan head until the dots meet, then the laser is focused. Finally, see our guide on Galvo Laser Focusing for a manual method of determining optimal focus.

Material Test Setup¶

LightBurn has a handful of Built-In Presets that make setting up your first Material Test straightforward.

Note for Galvo laser users

The range of reasonable settings for Galvo lasers is too great for LightBurn to include Galvo presets. Consult your laser's manufacturer, or search our forum for guidance from other users. Visit our Material Test reference page for information on configuring a test grid manually.

To open the Material Test, go to Lasers Tools → Material Test.
You'll see fields to select from a list of parameters to test, adjust the range of tested values, and change the size, position, and number of test boxes.
Instead of adjusting those fields manually, select a preset from the dropdown menu. You'll see two Built-In Presets each for Diode and CO₂ lasers, one Cut test, and one Engrave test. Select the appropriate Engrave preset for your type of laser.
LightBurn will automatically populate the Material Test fields with a range of values that should provide a good starting point for almost all lasers of your selected type.

Previewing¶

LightBurn has automatically applied all of the important settings for you, but checking the Preview window before you start any job is still a good habit to get into.

Click the Preview button to open the Preview window.
You'll see a still image of what the final test grid will look like. Press Play to see a simulation of the order in which the grid will be engraved.

Click here to learn more about the Preview window

When you first open the Preview window, you'll see a still image of the final result of your project — the contours to be scored or cut by Line Mode will be indicated by black lines, and the areas to be etched or engraved by Fill Mode will be shown as solid black areas, or, if your Line Interval is relatively large (or you zoom in close enough) as parallel lines running across the filled shapes.

You'll also see red lines — these lines indicate the path your laser will travel while not firing. You can toggle Show traversal moves at the bottom of the Preview window to switch between showing these moves or not.

Press Play to see a simulation of the movements and lasering operations your laser will perform when you start the job. In addition to making sure the laser will outline or engrave the correct graphics and areas, you'll be able to make sure it performs those actions in the order you want.

By default, the simulation will play in a close approximation of the job's real runtime, and Total time estimated is shown in the bottom right. You can adjust the Playback Speed slider to speed up or slow down the simulation.
The order in which test boxes are cut or engraved is determined according to an ascending list of potential risk of burning or charring material.

In other words, boxes with the highest Speed and lowest Power will run first, followed by the next highest, lowest, and so on.

Framing¶

The final check before you run the Material Test is to make sure that it will output in the location you're expecting.

Click the Frame button to tell your laser to trace a box around the area the test grid will be engraved.

Click here to learn more about Framing

Bounding Box Frame

Bounding Box framing commands the laser to trace a path defined as the smallest possible rectangle that will fully contain all graphics you're sending to the laser.

Here's a representation of that path in LightBurn:

And here's the laser following that same path during Framing:

Framing with Current Position

Here we've selected Current Position as the Start From mode, and the top right Job Origin position, so the laser moves down and to the left from its starting position:

Here's Current Position again, but with the center Job Origin position selected — now the laser moves out from where it's sitting, and traces a rectangle centered on the location where it began:

Note for Galvo laser users

If you have a Galvo laser, the grid will be outlined by your laser's red dot light instead. See Galvo Framing for more information.
If the area your laser frames is correct, you're ready to start the job. If not, what you do next depends on how far off it is.
Having trouble seeing where your laser is Framing? Click here for tips
Click here to learn how to fire your laser at low power during Framing (diode lasers only)

If your laser has a red dot pointer, it makes framing easier to see. Otherwise, your laser will travel around with the laser turned off. LightBurn does offer the ability to run diode lasers at a very low power to aid in Framing. To do so:
1. Go to Edit → Device Settings to open the Device Settings window.
2. In the Basic Settings tab, toggle on the Enable laser fire button and Laser on when framing settings. Click OK to apply.
3. The Move Window should now have a Fire button and a box to enter a power level. Keep this value very low to avoid burning the material — start at 0.25%, and only increase that value only if the beam is not visible.
4. The Fire button will toggle the laser on and off. Now you can use the Frame command with the laser visible.
5. Adjust the position of the material and/or the laser head until you're happy with the layout of the design.
  
  Danger
  
  The Fire button should only be used for diode lasers, which generally don't have a red dot pointer for Framing.
  
  Always wear proper eye protection when Firing your laser. Consult your laser's manufacturer for information on the proper eye protection required for your laser.
  
  This should never be used for a CO₂ laser, which has an invisble beam that could blind you or start a fire.
Click here to learn how to run Framing repeatedly, until you tell it to stop

Frame Continuously is an option in the Device Settings window that tells your laser to repeatedly Frame the same path until you tell it to stop.

Sometimes you won't get the positioning just right on your first try, but a little nudge of your material will do the trick. Other times, you'll just want to want to double or triple check the position. In either case, Frame Continuously will be a big help.

To enable it:
1. Go to Edit → Device Settings to open the Device Settings window.
2. In the Basic Settings tab, toggle on the Frame Continuously setting. Click OK to apply.
3. Now when you click either of the Frame buttons, a dialog window will open, letting you know that continuous Framing is active, and to press OK when you're ready to stop.
If it's close, but a little bit off the material, try nudging the material (if you have room) to align it to the framed area. If you don't have room, you'll need to exit the Material Test Generator window and jog your laser to a better position.
If it's very far off, it's likely you didn't select the correct Start From mode or Job Origin position. Revisit the Material Test Positioning step, or see Coordinates and Origin.
After making corrections, be sure to Frame again. Repeat as many times as necessary, until you've got everything lined up properly.

Running the Job¶

It's time to start your laser — this is the fun part!

Press the Start button in the Material Test Generator window to tell your laser to begin engraving the test grid.

Warning

Never leave a Material Test or any other job running unattended. If you are working with a relatively flammable piece of material such as cardboard, pay special attention when the job reaches the test boxes with the lowest Speeds and highest Powers. Be ready to stop the job and use fire supression equipment.
When it's finished, examine the results — find the box that achieves the nicest engraving and make note of them, apply those settings to a Fill layer in the Cuts / Layers Window, or create and save an entry in the Material Library.

Repeating for Cuts¶

Note for Galvo laser users

If you have a Galvo laser, its cutting capability is most likely extremely limited. We recommend skipping this test.

Once you've identified optimal engrave settings, you may want to test again for cuts.

Avoid damaging your work area

Since you'll be cutting through the material, make sure that whatever is underneath your material is either scrap that you don't mind burning into or won't be damaged by lasering. This might be a thin sheet of aluminum, a honeycomb bed, or a piece of scrap wood.

Re-position your laser over an un-used section of your material, or place a new piece of material in your laser's work area.
Go to Lasers Tools → Material Test to open the Material Test Generator again.
Select the appropriate Cut test preset for your type of laser from the Presets dropdown menu.
Preview and Frame the job.
Run the job.

Warning

Never leave a Material Test or any other job running unattended. If you are working with a relatively flammable piece of material such as cardboard, pay special attention when the job reaches the test boxes with the lowest Speeds and highest Powers. Be ready to stop the job and use fire supression equipment.
When it's finished, examine the results. You're looking for the box that cuts through the most cleanly, without charring. If several cut through with similar amounts (or lack of) charring, you can select the one that achieved a clean cut at the fastest speed.

Make note of those settings, apply them settings to a layer set to Line Mode in the Cuts / Layers Window, or create and save an entry in the Material Library.
If none cut through, you'll need to make some manual adjustments.
In the second column, open the dropdown menu to replace the Power parameter with Passes.
In the same column, set Count to 9, and Min to 2.
Click Edit Material Setting in the lower left to open the Cut Settings Editor, and set the Max Power to 100.0%.
After Previewing and Framing, run the test again.

Warning

Never leave a Material Test or any other job running unattended. If you are working with a relatively flammable piece of material such as cardboard, pay special attention when the job reaches the test boxes with the lowest Speeds and highest Powers. Be ready to stop the job and use fire supression equipment.
Select the box that cut through with the fewest Passes and highest Speed. Make note of those settings, and, along with the 100% Max Power setting, apply them to a Line layer in the Cuts / Layers Window, or create and save an entry in the Material Library.

If none of the boxes cut through, your laser most likely isn't capable of cutting through the material you're testing.

Framing

Next: First Project

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