But what about a laser engraver without the laser ... He mentions adding a shutter to douse the cutting beam to allow raster patterns, but even better might be a servo-controlled iris diaphragm ...

Laser cutting and engraving machines have been around for ... which will help keep you safe from the invisible blindness beam your K40 puts out when your other safety measures fail.

where the beam is directed via mirrors and a lens. Unlike larger machines, where the laser module moves parallel to the work surface. For engraved designs, this isn't an issue. However ...