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Reference & ToolsModule 7.5~3 min read

LightBurn Material Test

LightBurn builds test grids for you: Laser Tools → Material Test. It gives every box its own settings, labels the rows and columns, and runs the grid straight from the dialog, so there is nothing to import. KERF's part is knowing what to test. Pick your material and goal, then type the numbers into the dialog.

THE GRIDmore powerslowerEvery box gets its own speed andpower. Energy climbs toward theslow, high-power corner.READING A BOXtoo lightcleanoverburnedfaint, patchyeven, crispchar and haloRead it under a daylight LED atabout 45 degrees, the way acustomer will see the piece.WHICH BOX TO PICKmore powerslowerSeveral boxes usually work. Pickfrom the middle of the good zone,so small drift still lands inside.
Your grid may run in either direction, so go by the labels LightBurn burns beside it. What matters is the pattern: a band of boxes that work, and picking from the middle of it.

Run it in LightBurn, step by step

  1. Set where it runs. Choose Start From in the Laser window before you open the tool. Current Position and User Origin work like any other job; Absolute Coordinates places the grid at the X Center / Y Center values. Put scrap from the same batch as the real job under the laser.
  2. Open it: Laser Tools → Material Test.
  3. Vertical / Rows: enter Count, Param, Min, Max and Height from the helper above.
  4. Horizontal / Columns: enter Count, Param, Min, Max and Width.
  5. Edit Material Setting: the base layer for every box. The two Params vary across the grid; everything else you set here (mode, interval, frequency, passes) applies to every box. Use the helper's line.
  6. Labels and border: turn on Enable Text so the rows and columns are labeled on the part itself. Edit Text Setting sets how the labels burn. Enable Border adds an outline around the grid (LightBurn 1.5 and newer).
  7. Preview, then Frame. Preview shows the grid on screen; Frame traces its outline on the material so you know it fits.
  8. Start, or on controllers that support it, Send it to the laser or Save RD file (Ruida). LightBurn runs the least risky boxes first: highest speed, lowest power, lowest interval, fewest passes.
  9. Read it under daylight LED at about 45°. Pick the box that hits your goal with margin on both sides, not the one on the edge of failing.
  10. Keep it. Save the winning settings to your Material Library, and save the dialog setup as a Preset so the next test is one click.
Check your speed units first
LightBurn can show speed in mm/s or mm/min (Device Settings → Dimensions / Units). KERF's numbers are mm/s. Typed into a mm/min setup, 2000 means about 33 mm/s: far too slow, which over-burns and can start a fire.

Fiber and diode notes

  • Fiber (galvo): Material Test can also vary Frequency, and Q-Pulse width on MOPA sources, if your device supports them. Use pulse widths your source actually offers.
  • Diode: LightBurn ships four built-in Material Test presets for diode and CO2 lasers in the Presets dropdown. Run one as your first grid, then narrow it with the settings in the Diode tab.

What to test, and when

GoalRowsColumnsWhy
Black on stainlessSpeed 2000-5000 mm/sPower 10-30%Find the safe margin where black is solid but not over-driven
Color anneal bluesSpeed 200-1400 mm/sFrequency 40-100 kHzMap the color spectrum across speed × frequency
Color anneal, finePower 10-40%Q-Pulse 100-400 nsMOPA-specific tuning for dialed-in colors
Deep engrave depthPasses 5-25Power 60-100%Find the sweet spot of depth per minute
Photo contrastSpeed 2000-4500 mm/sPower 8-20%Find the contrast range before the image goes flat or burned
Anodized AL white popQ-Pulse 8-30 nsPower 25-55%Find the pure white before burning into bare aluminum
Cutting (CO2)Speed 3-16 mm/sPasses 1-3Pick the fastest speed and fewest passes that cut cleanly through
Test grid hygiene
Run grids on a single material lot, write the lot/supplier on the back of the sample plate, store grids in a binder by material. Six months from now when you re-order from a new supplier, you'll re-run the grid. Five lots later you'll know which suppliers are consistent.