Laser & Production

Common causes

• Focus is off
• Material is warped
• Lens or mirrors are dirty
• Power is too low
• Speed is too fast
• Air assist is weak or blocked
• Material has glue pockets or inconsistent density
• CO₂ laser mirrors are misaligned
• Diode laser is underpowered for the material thickness

Fix it

• Clean the lens before testing again.
• Check focus at the material surface.
• Pin or weigh down warped material.
• Slow speed by 10-20% and test again.
• Add one extra pass instead of forcing one extremely slow pass.
• Check that air assist is actually blowing at the cut point.
• For CO₂ lasers, check mirror alignment and lens condition.
• For diode lasers, use thinner material if production time becomes unreasonable.

Quick test: Cut a 1-inch square in each corner and the center of the sheet. If some cut and some do not, the issue is usually material flatness, bed level, focus, or inconsistent wood.

Common causes

• Speed is too slow
• Power is too high
• Air assist is too weak
• Smoke is trapped under the wood
• Honeycomb bed is dirty
• Material is resin-heavy or glue-heavy

Fix it

• Increase air assist.
• Raise the material slightly off the honeycomb.
• Clean the honeycomb bed.
• Use masking or transfer tape.
• Try faster speed with more passes.
• Use better-quality MDF, birch, or basswood.

Production tip: For diode lasers, multiple faster passes often give cleaner edges than one very slow pass.

Why it happens

Smoke, heat, and flashback from the honeycomb bed mark the back side of the material.

Fix it

• Clean the honeycomb bed.
• Lift the wood using pins, magnets, or risers.
• Improve exhaust airflow.
• Use masking on the back side.
• Use a sacrificial board for small pieces.
• Reduce power slightly and add another pass if needed.

Common causes

• MDF sheet is warped
• Laser bed is not level
• Focus changes across the sheet
• MDF has dense glue pockets
• Air assist is not reaching the cut evenly

Fix it

• Pin down all corners and edges.
• Use smaller sheet sections.
• Check bed level.
• Run a test square in several areas.
• Try a different MDF supplier if the issue repeats.
• Add a cleanup pass after the main cut.

Common causes

• The image was auto-traced incorrectly
• The design uses hollow lettering
• There are duplicate layers
• Objects are stacked on top of each other
• There are hidden cut paths

Fix it

• Use Preview before cutting.
• Delete duplicate layers.
• Check for hidden objects.
• Use one clean closed cut path per piece.
• Avoid hollow fonts unless they are intentional.
• Use node edit to remove messy traced areas.

Possible file problems

• Open paths
• Duplicate cut lines
• Too many nodes
• Overlapping objects
• Unjoined shapes
• Hidden layers
• Score lines accidentally set to cut

Fix it in LightBurn

• Preview the entire job before cutting.
• Use Optimize Cut Path.
• Simplify overly complex paths.
• Check all layer colors and settings.
• Zoom in and inspect problem areas.
• Make sure every cut piece is one clean closed shape.

Common causes

• Too much engraving
• Too many tiny details
• Too many layers
• Material is too thick
• File has excessive nodes
• Diode laser is being used for CO₂-style production

Fix it

• Use 1/8" material for paint party production when possible.
• Remove unnecessary engraving.
• Use score lines only where they help painters.
• Simplify decorative fonts and artwork.
• Choose designs with larger paintable pieces.
• Batch similar pieces together.

Paint party rule: If one project takes too long to cut repeatedly, it is probably too detailed for class production.

Common causes

• Thin script fonts
• Fragile swirls
• Tiny detail pieces
• Weak plywood grain
• Design was scaled too small

Fix it

• Use thicker fonts.
• Increase connection points.
• Remove tiny details.
• Use MDF for fragile lettering.
• Make small pieces larger before cutting.
• Avoid delicate tails, thin vines, and skinny outlines.

Common causes

• Pieces were not test-fit before class
• Paint buildup changed the fit
• Layer pieces are too small
• Cut file has alignment issues
• Glue areas are too narrow

Fix it

• Test assemble one full sample before selling the project.
• Make tabs and overlays slightly more forgiving.
• Use larger glue surfaces.
• Avoid extremely tight slots for beginner paint parties.
• Keep assembly simple enough for first-time painters.

Common causes

• Focus is off
• Material is not flat
• Speed is too high
• Lens is dirty
• Artwork resolution is poor
• CO₂ mirrors may be slightly misaligned

Fix it

• Re-focus carefully.
• Secure material flat.
• Clean lens and mirrors.
• Use higher-quality artwork.
• Reduce speed slightly.
• Run a small engraving test before the full project.

Important note

CO₂ lasers are usually the better choice for acrylic. Most blue diode lasers cannot cut clear acrylic well because the beam passes through it.

Fix it

• Use CO₂ for clear acrylic when possible.
• Use cast acrylic for cleaner engraving.
• Check that the material is laser-safe acrylic.
• Use proper ventilation.
• Reduce power or increase speed if edges are melting too much.
• Never cut PVC or unknown plastic.

Check these first

• Dirty lens
• Dirty mirrors
• Weak air assist
• Loose belts
• Material changed suppliers
• Focus tool or bed height changed
• CO₂ tube may be weakening
• Diode lens may be contaminated by smoke residue

Fix it

• Clean optics.
• Check air assist tubing.
• Check belt tension.
• Run the same test file on the same material.
• Compare current results to your known good settings.

Common causes

• Loose belts
• Material shifted
• Cut order caused pieces to move
• Small pieces fell into honeycomb
• Machine lost steps
• File was moved between layers incorrectly

Fix it

• Check belt tension.
• Secure material before cutting.
• Cut inner details before outer shapes.
• Use tabs if needed.
• Do not bump the machine during a job.
• Preview cut order before starting.

• Lens is clean
• Mirrors are clean and aligned, for CO₂ lasers
• Air assist is working
• Exhaust is working
• Material is flat
• Correct material thickness is selected
• Correct LightBurn layers are set to cut, score, or engrave
• Preview looks correct
• One sample has been test cut and assembled
• Small pieces are not too fragile for beginners