Contents
A beam combiner laser is a single machine with two distinct cutting modes. Understanding that distinction — and setting up each mode correctly — is the starting point for getting consistent results on both metal and acrylic.
The parameters in this guide come from Yongli 280W CO₂ tube production tests. They are starting-point reference values; your specific material grade, surface condition, gas purity, and optical alignment will all influence where the optimal settings land. Always verify on test pieces before running production.
What Is a Beam Combiner Laser?
A beam combiner laser integrates two separate laser sources into one cutting head. A dichroic mirror inside the head aligns both beams coaxially — they exit through the same nozzle, focused to the same point on the workpiece. The two sources are:
CO₂ Tube (280W)
Infrared, 10,640 nm wavelength. Efficiently absorbed by acrylic, wood, MDF, leather and other non-metals. Not well absorbed by bare metal surfaces.
λ = 10,640 nmcoaxially
Fiber Laser Component
Near-infrared, ~1,064 nm wavelength. Well absorbed by metals. Used with oxygen assist for cutting stainless steel and carbon steel.
λ = ~1,064 nmOne cutting head — two materials
Switching between metal mode and acrylic mode requires changing the assist gas supply and loading the corresponding parameter file. No physical cutting head change is needed — the same head handles both materials.
The "280W" label refers to the CO₂ tube power. This is what determines acrylic cutting depth and speed. The metal cutting capability depends on the fiber laser component's specifications — and that component typically delivers much lower peak power than a dedicated fiber laser machine, which is why metal cutting speed on a beam combiner is lower than on a dedicated fiber system. This is not a defect; it is the nature of a versatility machine.
Two Modes, Two Setups
Every time you switch materials from metal to acrylic or vice versa, five things change. Missing any one of them produces poor results — most commonly, acrylic cut with O₂ settings (fire risk and blown edges) or metal that won't cut because air can't assist the process.
Acrylic Mode
Metal Cutting Parameters (O₂ Assist)
The following parameters apply to stainless steel and carbon steel in the range 0.4–2.0mm using oxygen assist gas. These are starting-point reference values from Yongli 280W production tests. Material grade, surface condition, and gas purity all affect results — verify on a test piece before production.
↔ Swipe to view full table
| Thickness | Speed (mm/s) | Power (%) | Open delay (ms) | Dot interval (ms) | O₂ pressure (MPa) |
|---|---|---|---|---|---|
| 0.4 mm | 120–150 | 85–95% | 400–600 | 400–600 | 0.2–0.4 |
| 0.6 mm | 100–130 | 85–95% | 400–600 | 400–600 | 0.4–0.6 |
| 0.8 mm | 80–100 | 85–95% | 400–600 | 400–600 | 0.4–0.6 |
| 1.0 mm | 40–60 | 85–95% | 400–600 | 400–600 | 0.6–0.8 |
| 1.2 mm | 30–50 | 85–95% | 400–600 | 400–600 | 0.6–0.8 |
| 1.5 mm | 20–30 | 85–95% | 800 | 800 | 0.8–1.0 |
| 2.0 mm | 10–20 | 85–95% | 800 | 800 | 0.8–1.0 |
Note: The 0.8mm O₂ pressure in the source data shows "0.406" — this is a formatting issue in the original file. The intended value is 0.4–0.6 MPa, consistent with adjacent entries. Do not use 0.406 as a literal pressure value.
Open Delay and Dot Interval — What They Are and Why They Matter
These two parameters appear in the metal cutting table and are absent from acrylic cutting. Operators who are used to standard CO₂ acrylic cutting often set these to zero by habit when switching to metal — this is one of the most common causes of incomplete cuts and rough cut starts.
Open delay
Open delay is the time in milliseconds that the laser fires at the start position before the cutting head begins moving. When cutting metal, the laser needs to fully pierce through the sheet at the entry point before the cut path starts. Without sufficient open delay, the head begins moving before penetration is complete — the start of every cut line will be incompletely pierced, leaving a tab or a tear instead of a clean entry.
Dot interval
Dot interval controls the time between the end of the pierce sequence and the start of cut motion. It allows the molten pierce material to clear from the kerf before the head begins moving, reducing the risk of blowback contaminating the lens or causing a rough start. In practice for this system, dot interval is set to the same value as open delay.
Thin to mid steel (0.4–1.2 mm)
400–600 msShorter pierce time needed — material is thinner and the laser punches through more quickly. Use the lower end (400ms) for 0.4mm, the upper end (600ms) for 1.2mm.
Thicker steel (1.5–2.0 mm)
800 msNear the practical limit of this system's fiber component. Full 800ms pierce time ensures complete penetration before cut motion starts. Do not reduce this value — incomplete pierce at 1.5–2.0mm produces poor cut entry quality.
Acrylic Cutting Parameters (Air Assist)
The 280W CO₂ component gives this system a genuine thickness advantage over standard 150W CO₂ machines. At 30–35mm acrylic, the higher tube power provides the additional energy needed to reach a depth that a 150W machine typically cannot achieve reliably in a single pass. At 35mm, cutting speed is 1 mm/s — plan production time accordingly for thick sections.
↔ Swipe to view full table
| Thickness | Speed (mm/s) | Min Power (%) | Max Power (%) | Open delay (ms) | Dot interval (ms) | Air pressure (MPa) |
|---|---|---|---|---|---|---|
| 3 mm | 40–60 | 60–70% | 70–75% | 0 | 0 | 0.2–0.4 |
| 8 mm | 10–15 | 60–70% | 70–75% | 0 | 0 | 0.2–0.4 |
| 12 mm | 8–12 | 60–70% | 70–75% | 0 | 0 | 0.2–0.4 |
| 20 mm | 3–5 | 60–70% | 70–75% | 0 | 0 | 0.2–0.4 |
| 30 mm | 2 | 60–70% | 70–75% | 0 | 0 | 0.2–0.4 |
| 35 mm | 1 | 60–70% | 70–75% | 0 | 0 | 0.2–0.4 |
Intermediate thicknesses (5mm, 6mm, 10mm, 15mm, 25mm) are not in the source data. For these, interpolate between the nearest two entries and verify on test material. Edge quality at 30–35mm depends heavily on bottom ventilation and air flow direction — reduce top-surface air pressure and ensure adequate airflow beneath the sheet.
Min/Max Power for Acrylic — Why Two Values and Not One
If you have cut acrylic on a standard CO₂ machine, you may be used to setting a single power percentage. The beam combiner's CO₂ tube uses a different control method — you set both a minimum and a maximum power, and the controller modulates between them during the cut.
The key guidance from the Yongli source data: the difference between Min and Max power should be approximately 5 percentage points. For example:
Min/Max power pairing — recommended 5% difference
The Min/Max range given in the parameter table is 60–70% (Min) and 70–75% (Max). These represent the tested operating window, not a single fixed pair. Choose a starting pair within these bounds and keep the difference at 5%.
Why the 5% difference matters
CO₂ glass tubes modulate power by varying the duty cycle of the discharge. At corners, curves, and deceleration points in the cut path, the controller automatically reduces the power output to avoid overheating. If Min and Max are set to the same value, the tube fires at constant power through these transitions — acrylic corners typically show char marks, melting, or a wider kerf at the entry and exit of each curve.
With a 5% Min/Max gap, the controller has room to reduce to the minimum value at slow-motion points while maintaining the maximum at full-speed straight runs. The result is more consistent edge quality across the full cut path, including complex shapes and tight radii.
Performance vs Dedicated Machines — Honest Comparison
A beam combiner is a versatility tool, not a performance tool. Understanding where it is competitive and where it falls short helps you set accurate expectations and use the right machine for each job.
↔ Swipe to view full table
| Criterion | BC 280W (this guide) | Standard CO₂ 150W | Dedicated 1KW fiber |
|---|---|---|---|
| 3mm acrylic speed | 40–60 mm/s | 35–40 mm/s | Not suitable (fiber ≠ acrylic) |
| 20mm acrylic speed | 3–5 mm/s | ~3–4 mm/s | Not suitable |
| 35mm acrylic | 1 mm/s (achievable) | Not achievable reliably | Not suitable |
| 0.4mm SS speed | 120–150 mm/s | Not suitable (CO₂ ≠ metal) | ~200+ mm/s |
| 1.0mm SS speed | 40–60 mm/s | Not suitable | ~200 mm/s (3–4× faster) |
| 2.0mm SS speed | 10–20 mm/s | Not suitable | ~70–80 mm/s (4× faster) |
| Metal above 2mm | Not achievable | Not suitable | Up to 60KW / 200mm |
| Wood / MDF | Yes (CO₂ component) | Yes | Not suitable |
| Single machine for both | Yes — key advantage | No | No |
The metal cutting speed gap is significant. On 1mm stainless steel, a dedicated 1KW fiber laser is roughly three to four times faster than this beam combiner system. For shops running metal cutting as their primary production activity, this gap translates directly to throughput and cost per part. The beam combiner is not the right tool for that scenario.
Where the beam combiner genuinely excels: thick acrylic above 30mm, where a 150W CO₂ machine cannot reliably achieve single-pass cuts, and mixed-material jobs that would otherwise require two separate machines and setups.
When a Beam Combiner Is and Isn't the Right Tool
Good fit for a beam combiner
- You cut both thin metal (≤2mm) and acrylic/non-metals regularly from a single machine
- Your metal cutting volume is low or batch-size-one — speed is less critical than versatility
- You make products that combine acrylic and metal (trophies, signage, awards, nameplates)
- You need to cut thick acrylic (20–35mm) that a standard 150W CO₂ machine cannot reach
- Budget or space constraints rule out two separate machines
- Prototype and sample production across mixed materials
Not the right tool — consider a dedicated machine
- Metal cutting is your primary business and throughput matters — a dedicated fiber laser is significantly faster
- You need to cut metal thicker than 2mm — this system cannot do it
- Your acrylic volume justifies a dedicated CO₂ machine optimized for that material
- You require consistent high-speed metal cutting on a production line
- Edge quality on metal is critical — dedicated fiber gives better results on thin SS at speed
Troubleshooting
Metal cut start has a rough entry — incomplete pierce at the beginning
Likely cause: Open delay too short. The cut head began moving before the laser fully penetrated the sheet at the entry point.
Fix: Increase open delay by 100–200ms increments and test. For 1.5mm and 2.0mm steel, ensure open delay is set to 800ms — do not use the 400–600ms values from thinner material entries. Also check dot interval matches open delay. If the problem persists after correcting delay values, check O₂ pressure is within the table range and the lens is clean.
Acrylic has burn marks or charring at corners and curve entry/exit points
Likely cause: Min and Max power are set to the same value, or the difference is too large. The tube fires at constant power through deceleration zones, depositing excess energy at corners.
Fix: Set Min and Max power with a difference of approximately 5%. For example, Min 65% / Max 70%. If charring is severe, reduce Max power by 5% first, keeping the same difference. Do not reduce speed as the primary response — corner burning is primarily a Min/Max power issue, not a speed issue. Also verify the gas is air, not O₂, before changing power settings.
Switching from acrylic to metal — laser fires but does not cut through
Likely cause: Gas line not switched from air to oxygen, or O₂ pressure too low. Air assist cannot drive the exothermic cutting reaction needed for metal.
Fix: Verify the gas supply valve is switched to O₂ and the pressure is set to the table value for your material thickness (minimum 0.2 MPa for 0.4mm, up to 1.0 MPa for 2mm). Also confirm that open delay and dot interval are set per the metal table — not left at 0 from an acrylic session. If the machine is otherwise correctly configured and still not cutting through, check O₂ purity and regulator calibration.
Acrylic edge is cloudy or has a rough surface — not the expected smooth finish
Likely cause: Top-surface air pressure too high, or speed too slow for the current power setting causing excess heat to the edge face.
Fix: Reduce top-surface air pressure. For acrylic, directed airflow from the side or reduced top-blow is preferable to strong downward pressure, which cools the molten edge unevenly. If speed is already at best speed, try reducing Max power by 5% before reducing speed further. Ensure bottom ventilation is clear — trapped heat beneath the material contributes to edge quality degradation, especially on thicker sections.
Thick acrylic (20–35mm) shows tapered kerf — wider at top than bottom
Likely cause: Standard focal length lens being used at a depth that exceeds its focal depth. The beam diverges significantly below the focal point, widening the bottom of the kerf.
Fix: Switch to a longer focal length lens (100mm or longer). This extends the focal depth, keeping the beam narrower throughout the full thickness of the cut. Also set the focal point approximately at the mid-depth of the material — for 20mm acrylic, focus at approximately 10mm below the surface — and compare kerf width at the top and bottom of a test cut before running full parts.
Questions about your beam combiner setup?
The parameters in this guide are reference starting points from Yongli 280W production tests. If you are seeing results that differ significantly from these values, material grade, gas purity, optical alignment, or tube condition may be the variable. Our applications team can help diagnose and recommend adjustments for your specific setup.
When you contact us, it helps to include: material type and grade, thickness, current parameter settings, gas type and pressure being used, and a description of the cut result you are seeing.
FAQ
What is a beam combiner laser?
A beam combiner laser integrates two laser sources — a CO₂ tube and a fiber laser — into a single cutting head using a dichroic mirror. The CO₂ component handles non-metals such as acrylic, wood and leather. The fiber component handles thin metals with oxygen assist. One machine switches between both modes by changing the assist gas and parameter file — no physical head change is required.
How thick can a 280W beam combiner cut acrylic?
In production tests, 35mm acrylic is achievable at 1 mm/s. This is a genuine advantage over standard 150W CO₂ machines, which typically reach around 25mm. At 30–35mm, cutting speed is very slow — 1–2 mm/s — so plan production time accordingly. Ensure full ventilation and extraction are running at these slow speeds, as the laser dwells longer in any given area.
What is open delay in laser cutting?
Open delay is the time in milliseconds the laser fires at the entry point before the cutting head begins moving. For metal, this allows full penetration of the sheet before cut motion starts. Without it, cut starts will be incomplete. Acrylic requires zero open delay — the CO₂ beam enters immediately without a pierce sequence. Setting metal-mode open delay values on an acrylic job causes burn marks at the start of each cut line.
Why does acrylic use Min and Max power settings?
CO₂ glass tubes use a Min/Max power range to modulate output through corners, curves, and speed changes in the cut path. Setting them approximately 5% apart — for example, Min 65% / Max 70% — gives the controller room to reduce power at deceleration points, preventing char marks and overheating at corners. Setting Min and Max to the same value produces constant-power output that tends to burn acrylic at tight radii and direction changes.
Can a beam combiner replace a dedicated fiber laser for metal cutting?
Not for production-volume metal work. On 1mm stainless steel, a dedicated 1KW fiber laser cuts at roughly 200 mm/s — three to four times faster than the 40–60 mm/s this beam combiner achieves. The beam combiner is appropriate for low-volume metal work, samples, and mixed-material jobs. For regular high-throughput metal cutting, a dedicated fiber laser is typically the more appropriate choice. See the fiber laser cutting parameters guide for dedicated machine data.
