Lazrit
Material

Laser-Cut Acrylic Files: Cast vs Extruded, Bridges, Edge Polish

Acrylic looks forgiving until you try to cut sharp small detail or peel hot, brittle off-cuts off the bed. Cast acrylic gives the cleanest flame-polished edge. Extruded melts more, prone to gummy edges and stress fractures. Lazrit's acrylic profile defaults to a 1 mm minimum detail and a 2.5 mm minimum bridge — slightly wider than wood, because the cooled cuts are more brittle.

3 lifetime exports — no credit card.

Recommended cut settings

SettingDefault
Default thickness3 mm
Minimum bridge width2.5 mm
Minimum detail1 mm

Cast vs extruded — pick before you cut

Cast acrylic (e.g., Plexiglas G) has a glassy flame-polished edge straight off the laser. It engraves white-frost-on-clear. Extruded acrylic is cheaper, often comes off the bed gummy, and engraves clear-on-clear (no contrast). For laser work, cast is almost always worth the upcharge.

Recommended settings

3 mm cast acrylic on a 60 W CO2: ~7 mm/s at 80% power for cut, ~200 mm/s at 30% power for engrave. Keep air assist on — pooling smoke contaminates the edge polish. Lazrit's profile won't let you ship a part with bridges under 2.5 mm because cooled acrylic snaps where it shouldn't.

How Lazrit prepares acrylic files

Trace → topology check → auto-bridge → review. The bridges are placed where they're least visible (in concave corners, along straight runs) and can be polished off with a quick deburr or torch pass after the cut.

Common pitfalls

Tiny pointed shapes melt and lose tip definition. Anything below 1 mm should be rounded or removed. Avoid sharp inner corners on thin sections — they're stress concentrators that crack in shipping.

Frequently asked questions

Does Lazrit prevent thin cracks on acrylic?

Indirectly — by enforcing minimum bridge widths and minimum detail. It can't fix stress-concentration design choices like sharp inner corners on thin sections; the topology check will warn but it's your call to redesign.

Can I engrave acrylic with Lazrit?

Yes — mark any path as the engrave layer in the workspace. The export keeps cut and engrave on separate layers so LightBurn can apply different power/speed settings.

Does Lazrit support clear edge polishing?

We produce the cut file. Edge polish is a function of cast vs extruded stock, air assist, and laser tuning — Lazrit doesn't currently rewrite paths to compensate for kerf.

What thickness of acrylic does Lazrit assume?

3 mm is the default. Change the thickness in the workspace; the minimum bridge width scales with it.

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