Align your laser so the beam hits square every time
On a CO₂ machine the beam bounces off mirrors on its way to the lens. If those mirrors are off, power drops and cuts go inconsistent across the bed — alignment fixes it.
⚡ Rule of thumb
Align the mirrors so the beam lands in the same spot at the near and far end of each axis — use a tape target and low power to walk it in.
Starting point
Beam hits the same point near & far on every mirror
Measured
Burn-mark position at near vs. far travel
Confidence
Process-dependent
▶ Source video — How To Align Your Laser Perfectly EVERY TIME — Laser 101watch on YouTube ↗
Applies to
- Process
- CO₂ lasers with mirror-and-lens beam paths
- When
- Weak/inconsistent cuts, after a knock or a move
- Tools
- Masking tape target, low-power test pulses, safety glasses
Why it matters
Every mirror the beam misses costs power and moves the focused spot, so a part cuts fine in one corner and won’t cut through in another.
Aligning so the beam strikes the same point near and far on each axis keeps power and focus consistent across the whole bed.
What good looks like
- A low-power pulse lands in the same spot at both ends of travel
- Cut quality is even across the whole work area
- The dot enters each mirror and the lens centred, not clipped at an edge
How to apply it
- Put safety glasses on and drop power to a safe test level.
- Tape a target over a mirror and pulse the beam at the near and far positions of that axis.
- Adjust the previous mirror until the near and far marks overlap.
- Work mirror by mirror down the path to the lens, re-checking as you go.
Laser 101Source & visual reference
Walking the beam in with a tape target so it hits square near and far — How To Align Your Laser Perfectly EVERY TIME! (For Beginners) ↗.
Summarized and independently edited by Start Here. Starting values and cautions are our editorial notes, not a quotation from the creator.