This page describes a laser engraving setting published for Acrylique transparent (PMMA) at 3 mm, tested on a Glowforge Plus fitted with a CO2 40W source (10,600 nm CO2, 40 W). It states the exact machine, source, material, thickness and operation of the test; power, speed and number of passes are shown with a Premium pass.
Why those four facts matter: a engraving setting that works on Acrylique transparent (PMMA) at 3 mm does not transfer to another thickness, nor to another source. A 10,600 nm CO2 rated 40 W does not deposit the same energy as a stronger module, and the speed has to be adjusted accordingly. Copying a number without checking those four points is the first cause of a ruined part.
Published by LaserSettings (estimation). No other workshop has confirmed it yet: treat it as a starting point, and confirm it from your account if you reproduce it.
No photo comes with this setting yet. If you reproduce it, publish yours from your account: a picture of the result is worth more than a line of numbers.
Recommended routine before running the part: clean the lens, redo the focus, engrave a small test grid on an offcut of the same Acrylique transparent (PMMA), then adjust the speed rather than the power. Work with fume extraction and air assist, wear glasses rated for 10,600 nm CO2, and never leave the machine unattended.
Glowforge is an enclosed CO2 machine driven from a browser, with a framing camera and automatic material recognition. Its software often expresses power and speed in its own units: before reusing a setting from elsewhere, check the conversion, otherwise the numbers do not mean the same thing.
Cast acrylic is the material that gives the most beautiful CO2 laser results: a clear, glass-like polished edge with no finishing at all. But it demands the right source — and it does not cut with a blue diode.
Clear acrylic lets a diode's blue light straight through: the beam crosses the sheet without being absorbed and nothing cuts. The source is at fault, not your settings — raising power will not help. Only CO2 sources (10.6 µm) cut clear PMMA cleanly.
Black or coloured acrylic does absorb blue light: it cuts with a diode, but with a matt, unpolished edge.
Grade matters too: cast PMMA gives a clear edge, extruded (XT) gives a milky edge and distorts more. For a visible part, choose cast.
For a polished edge you need the opposite of what most people assume: a single, slow pass at high power. The material must melt through the whole thickness at once. Several fast passes give a striped, matt edge.
Turn air assist off (or way down) when cutting: the airflow cools the molten material and clouds the edge. It is the one material where you deliberately disable it.
When engraving, cut acrylic appears opaque white. Stay at low power and high speed: too much energy melts the edges of the path and the artwork smears.