Fiber Laser Engraver Safety

Just a few words about using a fiber laser engraver safely (with Balor or other software.)

Your default inexpensive fiber laser engraver from Aliexpress or eBay does not have any kind of safety enclosure or interlock. (Mine did at least come with some laser safety goggles, though they were not of a brand I recognized.) Yet, the 20W+ average power, 1064 nm light it produces is both invisible and not eye-safe. Near IR lasers like this have absolutely caused vision loss, and they usually do so insidiously.

The optical system involved in a laser engraver focuses the beam onto a surface. The beam will be diverging after passing through the focal point, so it’s unlikely to burn you or set anything on fire. (Especially as humans are fairly transparent to 1064nm, so the laser’s power will be distributed over a much greater volume of flesh than, say, metal.) However, it is still incredibly bright, even though it’s invisible! Using a cell phone camera, I can actually observe the diffuse reflection of the beam when marking with my machine, and it mostly winds up at about eye level if you are standing and the machine is at table height.

While the design of the optical system makes catastrophic (=instant blindness) eye damage unlikely, it could leave your vision field looking like a shotgun blast over many small accidents you probably won’t notice, or cause more subtle degradation. You should get IR protective goggles with an OD (optical density) rating appropriate to your machine. The OD rating and wavelength should be marked on the goggles. Make sure to get them from a reputable source. I tested various no-name laser goggles from overseas manufacturers in the lab and found about 1/3rd of them were grossly failing to meet their claimed rating - not good odds to bet your eyesight on.

Better yet, consider building an enclosure for your laser. You can get laser safety acrylic panels if you want to see what it is doing in there. This will also help to prevent danger to bystanders or pets who may not be wearing laser goggles.

You should consider fume extraction as well, especially if you are going to be marking plastics or metals that can cause metal fume fever, e.g. zinc or galvanized materials. This would include cutting PCB material, FR-4 base material is basically fiberglass held together with epoxy, a thermoset polymer.

Also, while we normally think of these lasers as ablating / disintegrating material rather than burning it, with the wrong settings, they can still set flammable things on fire. Be careful.

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I would use much stronger words: Operating any type of laser cutter, even if it “only” outputs a few hundred milliwatts. without an enclosure is wildly irresponsible.

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