Laser 101 · Troubleshooting
Why your laser is not cutting through.
A laser that scores the surface but will not cut through is one of the most common problems. Here are the causes, in the order worth checking.
When the laser stops cutting through
A laser that used to cut a material cleanly and now leaves it partly attached — or does not separate it at all — is one of the most common problems we are called about. It is almost always one of a few causes, and they are worth checking in order before assuming the worst.
Power, speed and focus
Start with the basics. Too little power or too much speed simply will not deliver enough energy to cut through — check your settings against the material and thickness.
Focus is the quiet culprit. The beam has to be focused to a fine point at the material surface; if the focus is off — the bed moved, the material is thicker than expected, the focus was never reset — the beam arrives wide and weak and only scorches. Re-set the focus and many ‘weak laser’ problems disappear.
Dirty or misaligned optics
Every mirror and the focusing lens has to be clean. A film of smoke residue on a lens absorbs energy instead of passing it, and that lost power shows up as a cut that no longer goes through. Inspect and gently clean the optics.
Alignment matters too — if the beam is not striking the centre of each mirror and the lens, power is lost at every bounce. A laser that cuts fine in one corner of the bed but not another is often telling you the alignment has drifted.
Material and an aging tube
Sometimes it is the material: stock thicker or denser than what the machine is set for, warped sheet lifting away from focus, or plywood with internal voids and glue that the beam cannot get through consistently.
And tubes age. A CO₂ laser tube slowly loses output over its working life — a tube near the end of its life cuts noticeably weaker than a new one, even at the same settings. If focus, optics, and alignment all check out and cuts are still weak across the whole bed, a tired tube is the likely answer.
When to call for help
Work through it in order — settings, focus, optics, alignment, material, tube. If you have checked them and the machine still will not cut through, that is exactly what our repair service is for. We diagnose CO₂ lasers on-site across Southern California and remotely by Zoom anywhere in the US, and we will tell you honestly whether it is a quick fix or a part.
Common questions
Why won't my laser cut all the way through?
Usually one of: too little power or too much speed, incorrect focus, dirty or misaligned optics, material thicker or denser than expected, or an aging tube. Check them in that order.
Could it just be the focus?
Very often, yes. If the beam is not focused to a point at the material surface it arrives wide and weak. Re-setting focus fixes many 'weak laser' complaints.
How do dirty optics affect cutting?
Smoke residue on a lens or mirror absorbs energy instead of passing it. That lost power shows up directly as a cut that no longer goes through. Clean optics restore it.
How do I know if my laser tube is worn out?
If focus, optics, and alignment all check out and cuts are weak across the entire bed, an aging CO₂ tube losing output is the likely cause.
Can you help diagnose it?
Yes — we repair CO₂ lasers on-site across Southern California and diagnose remotely by Zoom anywhere in the US. We will tell you whether it is a quick fix or a part.
Need it cut right?
Industrial CO₂ lasers and a repair team, in downtown Los Angeles. A real person checks every job.