ComMarker B4 Fiber Laser Complete Setup Guide: Focus Alignment, EZCad2, and Your First Mark

Fiber laser galvo marking has gotten dramatically cheaper over the last few years, and the ComMarker B4 is one of the machines that made a 20-60 W fiber marker a realistic desktop purchase instead of a used-industrial-equipment hunt. Unlike the general galvo fiber marking content already on this site, this guide is specifically about getting a B4 unboxed, aligned, and making its first clean mark — the model has a few setup quirks (lens swapping, beam alignment, software licensing) that trip people up on their first week with the machine.

What's in the Box and What It's For

The B4 ships as a desktop galvo fiber marker with a fixed bed, available in 20, 30, and 60 W configurations, and includes two interchangeable lenses: a 110 x 110 mm lens for high-accuracy, fine-detail work, and a 200 x 200 mm lens that trades some precision for a larger field. Most units also include a rotary attachment and a handheld marking frame, and ComMarker sells a separate enclosure for shops that want fully enclosed operation. Rated accuracy is around 0.01 mm, with speeds up to 15,000 mm/s and a quoted laser source life around 100,000 hours — numbers that are typical for this class of fiber source, not unique to ComMarker.

This is a marking and engraving tool, not a cutter. On metals (stainless steel, aluminum, brass, titanium, coated and anodized parts) it does deep, permanent marks and can anneal stainless to produce color marking; on plastics and some coated materials it can mark without engraving; on wood it generally needs to be pre-painted black first, since bare wood doesn't absorb the fiber wavelength efficiently the way it absorbs a CO2 or diode beam.

SpecValue Power options20 W, 30 W, 60 W fiber Lenses included110 x 110 mm (precision) and 200 x 200 mm (wider field) Accuracy~0.01 mm Max speedUp to 15,000 mm/s Max engraving depth~0.3 mm SoftwareLightBurn (Galvo module, paid add-on) or EZCad2 Focus methodManual height adjustment via front panel buttons, aligned using a 3-beam projection Safety featuresFront emergency stop; automatic shutdown on movement/tilt

Focusing: The 3-Beam Alignment

Unlike a CO2 or diode laser where focus is a single distance measurement, the B4 (like most galvo marking heads) projects three visible alignment beams onto the work surface. Before any job, you raise or lower the head using the front panel buttons until all three beams converge into a single point on the material — that convergence is your correct focus height, not a ruler measurement from a focus gauge. Getting this wrong is the single most common reason for a blurry, double-struck, or faint first mark, and it's worth testing the convergence on a piece of scrap after every lens swap, since the 110 mm and 200 mm lenses sit at different focal heights.

Software: EZCad2 vs. LightBurn

The B4 ships with EZCad2 (or a ComMarker-branded equivalent), the standard, free, if dated-looking, control software that most Chinese galvo fiber lasers use. It's capable and the fastest path to your first mark, but its UI, file import, and job-array handling are clunky compared to what diode and CO2 users are used to. ComMarker also supports LightBurn through LightBurn's paid Galvo add-on (roughly $80–90 on top of a LightBurn license) — if you already own LightBurn for a diode or CO2 machine, the Galvo module gets you a consistent interface across all your lasers, proper array/indexing tools for marking parts in batches, and far better text and barcode handling than EZCad2's. For one-off hobby marking, EZCad2 alone is fine; for any kind of batch or production work, the LightBurn Galvo license pays for itself quickly in time saved.

Dialing In Settings

Fiber marking parameters (power %, speed, frequency, and for MOPA-capable units, pulse width) behave very differently from CO2/diode power-and-speed settings, and published "starting point" tables for stainless steel, aluminum, brass, and anodized aluminum are a much better starting point than trial and error. Always run a small test grid — a 3x3 or 4x4 array varying speed and power on scrap material of the exact type and finish you'll be marking — before committing to a real part, since finish (brushed vs. polished vs. anodized) changes the correct settings more than the base metal does.

Safety Notes

Fiber lasers operate in the near-infrared (around 1064 nm), which is invisible and far more dangerous to eyesight than a visible diode beam, because your blink reflex won't protect you — you can suffer permanent retinal damage from a reflected or stray beam without ever seeing it coming. Correct, laser-rated (OD rated for 1064 nm specifically, not generic "laser glasses") safety eyewear is non-negotiable any time the machine is running outside a fully interlocked enclosure, even during setup and focus alignment. The B4's front emergency stop and tip/movement shutdown are useful safeguards, but they protect against gross failures, not against someone standing over an open bed without eyewear during normal operation. Keep hands and reflective jewelry out of the beam path, and treat the machine the same way you'd treat any industrial marking laser, not like a diode engraver.

For makers who outgrow CO2/diode metal marking workarounds (CerMark paste, annealing tricks, sacrificial coatings) the B4 is a genuinely different tool, not just a more expensive diode laser — it's worth the learning curve on focus and software if metal marking and jewelry/tool engraving is a real part of what you make.