AtomStack A5 Pro 40W Complete Setup Guide: Assembly, LightBurn, and Your First Cut

The AtomStack A5 Pro is a budget-tier open-frame diode laser with a 410x400mm work area and a 40W-rated diode module — on paper, double the headline power of this site's usual reference machine, the Longer Ray5 20W. In practice, the gap in real cutting performance is much smaller than the wattage numbers suggest, and this guide covers assembly, LightBurn setup, and a sane first cut, with an honest look at what that power rating actually buys you.

What's in the Box and Frame Assembly

Like most open-frame diode machines in this price class, the A5 Pro ships as a kit: two X-axis rails, a Y-axis gantry, the laser module itself, belts, a controller box, and the honeycomb or slat work surface. Assembly follows the same sequence as every other GRBL-based open-frame kit on this site: square the two rails to each other before tightening any frame bolts down, check belt tension on both axes by hand (snug with a slight give, not guitar-string tight), and mount the laser module last so you're not fighting its cable routing while the frame is still loose. Run the gantry to both ends of travel by hand before powering on to confirm nothing binds.

Connecting and Configuring Software

The A5 Pro supports USB and WiFi connectivity and works with the AtomStack App, LaserGRBL, or LightBurn — LightBurn is the better choice for anyone planning serious production work, the same recommendation this site gives for every GRBL machine. Add it as a new device in LightBurn, select the GRBL device profile, and connect over USB for your first session (WiFi is convenient once you trust the machine, but a wired connection removes a variable while you're still troubleshooting). Pull the machine's current GRBL settings into LightBurn and confirm your travel limits match the 410x400mm work area before running anything.

Homing and Origin

Check whether your unit shipped with limit switches wired and enabled, since budget open-frame kits in this tier sometimes ship without them active by default. If there's no working homing cycle, treat the current head position as your origin at the start of every session exactly as you would on the Ray5, and don't rely on power-cycling to restore a known position.

Focus and Air Assist

Focus by whatever means the included focus tool provides — typically a fixed-distance block you rest the module on at the material surface before locking the module height. Fine material thickness variation calls for a quick focus re-check, the same rule that applies to every diode laser on this site. Connect air assist before your first cut, not after; clean cuts and reduced flare-up risk depend on it from the very first test, not just on "real" jobs.

First Cut Settings

MaterialSpeedPowerPasses Cardboard (test cut)400mm/min40%1 3mm plywood120mm/min90%2 3mm acrylic (cast)80mm/min90%2–3 2mm leather (engrave)300mm/min35%1 Stainless steel (mark only)200mm/min90%1

Treat this table as a starting point and run a proper power/speed test grid before committing good material, the same as you would with any new laser — individual module output and focus accuracy vary enough between units of the same model that a published setting sheet is never the last word.

The Honest Power Comparison

A 40W-rated diode module doesn't cut twice as deep or twice as fast as a 20W-rated module like the Ray5 in real use. Diode "wattage" ratings on budget machines are frequently combined-diode input power figures rather than measured optical output at the work surface, and actual cutting performance between 20W and 40W-class open-frame diode machines in this price tier is often closer than the spec sheet implies. Expect a real, noticeable improvement in cut-through thickness and speed over a 20W unit — especially on darker, harder-to-cut materials — but don't expect the number on the box to translate one-to-one into capability.

Safety

This is still a Class 4 laser once the enclosure is open or absent, same as every other diode machine covered here: wear OD-rated laser safety glasses matched to the module's wavelength any time the beam could be exposed, run it in a ventilated area, keep a fire watch during cuts (especially on anything you haven't test-cut before), and never leave it running unattended.

As a second machine alongside a Ray5 or similar unit, the A5 Pro's larger bed and higher rated power make it a reasonable choice for bigger sheet goods and thicker material, while keeping the smaller machine dedicated to detail engraving work.