loading

Perhaps you've bought one? They usually cost $80-$150, are advertised as something like "Laser Engraver Printer Cutter Carver DIY Engraving Machine," and have names like NEJE and SuperCarver. They're quite cute, with a laser module that looks like a little laser pointer wrapped in a heat sink. However, that cute little laser is most commonly 300mW, 500mW, or 1000mW. That's plenty of power to quickly burn designs into wood -- also more than enough to cause serious injury almost immediately if used in unsafe ways.

In the US, I think many people have gotten used to the danger of low-power lasers being overstated. Looking directly into the beam from a Class IIIa laser device, such as laser pointer or laser scanner, could be hazardous to the eyes, but they are otherwise quite safe. The catch is that those devices only deliver between 1mW and 5mW. The laser in your cheap engraver might look like a laser pointer, but it delivers enough power to require very different handling to be safe.

Avoid the temptation to try things first and read instructions after a serious problem has surfaced: I didn't even plug-in my laser's power supply until after I had built an enclosure for the unit.

I'm not an expert in the law, nor in laser safety. I'm just a maker who sees the potential, both good and bad, of these little engravers. You bear all responsibility for safe configuration and operation of your laser. I'm writing this Instructable to try to make folks more aware of the potential for serious bad... and to describe what I did with the intent of reducing the risk and improving functionality. In sum, when you saw "DIY" in the advertising of these engravers, you probably wondered what was left for you to "Do It Yourself" -- the units seem fully assembled. The answer is mount the laser and add safety features.

Actually, this Instructable not only overviews the safety issues and suggests fixes, but also applies improvements that make the machine more consistent and easier to use. There are other ways it could be done, but I took advantage of 3D-printing to make custom parts upgrading the laser engraver -- and I've made my designs for those parts freely available so you can too. Never forget that you can use your tools to make better tools.

Step 1: What's The Worst That Could Happen?

Before going into the details of how we'll make the device safer, it's useful to get a quick understanding of how much damage misuse of one of these laser engravers could cause.

  • Eye injury: even 1/4 second accidental direct exposure to the beam of one of these lasers is not considered "eye safe" unless you are literally at least hundreds of feet away from the laser. It is quite possible to cause severe temporary or permanent vision defects by direct exposure, and even short-term exposure to a scattered (diffuse reflection) of the beam is hazardous. Of course, this also implies that trying to cut anything shiny is a bad idea, because shiny things will scatter a lot of laser light.
  • Burning: eyes aren't the only body part you can damage. A 1000mW laser will burn your skin just as easily as it burns wood or leather, and it burns them just about instantaneously.
  • Smoke: the material removed by a laser is burned and, to a great extent, released into the air. There are plenty of things you might think about engraving that you really don't want to be inhaling -- like any material containing chlorine (e.g., Vinyl or PVC). Also don't engrave Polycarbonate, Lexan, nor resin/coated materials like Fiberglass (e.g., circuit boards). Even ABS, which isn't all that bad when 3D-printing, produces nasty fumes when laser cut. Venting and/or filtering helps, but making good material choices is the best way to minimize problems. There are lots of lists of good and bad materials online: ATX HackerSpace, FabLab Devon, Pololu Robotics & Electronics, JR Laser Solutions, etc.

You can get more gory details about what damage lasers can do from many web sites, including the wikipedia article on laser safety, the laser safety facts web site, and OSHA's guidelines. These little semiconductor lasers definitely can hurt you, but.... DON'T PANIC! Think of it this way: using these lasers is truly dangerous if they are handled incorrectly, but so is improperly using many power tools or driving a car. Use reasonable care, and everything should be fine.

By the way, the sticker design above is the label I made to warn of the danger. I know it looks scary, and your laser probably didn't come with any such sticker, but it really should have. Put an appropriate warning sticker on your unit! At least print-out and fill-in the blank sticker above. The key elements for an appropriate warning are:

  • Show appropriate danger or warning markings, such as the triangular laser radiation symbol
  • Specify the laser class, maximum power, and wavelength -- give details
  • Indicate the primary dangers, which for these lasers is exposure of eyes to direct or indirect laser light or direct exposure of skin to the laser beam
  • State basic safety procedures, such as wearing protective eyewear or only operating the laser when the light is fully enclosed

It should go without saying that kids, and adults unaware of basic laser safety issues, should never be using this type of laser without supervision.

I spliced a computer fan so it's powered by USB, the enclosure; a Lego &quot;wind tunnel&quot; XD<br>Actually works quite well. Now I just need to construct the safety panels. I got the NEJE DK - 8 - KZ 1000mW laser engraver from Gearbest.com
<p>Very similar unit, but it has the X axis on the back rather than the top, so there are five open areas to enclose -- four sides plus the top. It's also a little harder to get a good placement of a webcam inside. The interesting thing is that unit uses a laser cut frame and if they had just not cut holes in four of the five sides, you'd have it almost enclosed....</p>
<p>Nice to see someone who has safety in mind for a change.</p>
<p>I have a suggestion for side-panel material:<br>Oxy/acet welding face shield lenses, in shade 5.<br>These<br> block UV and IR and are made to be optically clear, the other good <br>thing about these sort of lenses is that you can cut them to size/shape <br>with strong scissors or tinsnips.<br>Something like Cigweld part No. 454486 - Shade 5 Polycarbonate</p>
<p>Interesting. Welding has a much broader spectral profile than laser light, so it's not clear how effective the filters would be. The meaning of &quot;Shade 5&quot; is apparently governed by two formulas: OD = -log T and SN = 1 + (7/3) OD, where T = fraction of light transmitted by the material, OD = optical density, and SN = shade number. If so, Shade 5 is OD=1.7, which sounds feasible for laser light if it blocks the right wavelengths... but does it?</p>
<p>I used to use a 8031 to run a packaging machine and had 30 on off relays, a 360 degree encoder, and 3 heat encoders back in 1982. 8051 should be able today run a 7 axis machine not 2!</p>
<p>It's not quite just 2 axis. It does speed control on the fan and power control on the laser while talking via USB (well, serial converted to USB) and watching the 6 user buttons. It's rather memory starved -- apparently only 2KB RAM and the 520x520 image to carve goes into EEPROM. Anyway, I agree that it should be more than sufficient hardware to also run a standard G-code interpreter....</p>
<p>printing to metal... Is this setup possible?</p>
<p>The answer should be &quot;No.&quot; I suspect it could mark some metals, especially by burning coatings on them, but it isn't intended for that. In fact, it takes fairly high settings on my 1000mW to cleanly engrave the acrylic dice -- power 7/10, dwell time 150ms.</p>
Are you not worried that you will contaminate the lens if you enclose the unit?
<p>I do worry about the balancing of good filtration vs. sufficient airflow. For wood, I think the activated carbon filter is very viable with the tiny fan supplied with the unit; there is a reasonable flow through it with the fan at speed 10 and the burning wood odor is in the &quot;distant campfire&quot; range. I'm less confident I'm at a good filtering level for acrylic, but the little fan can handle a much better filter. I'm still looking at various upgrade options.</p><p>As for the lens per se, well, it's enough above the workpiece so that the fan has time to divert the smoke pretty well. I've done about 120 engravings so far without any obvious signs of that type of trouble....</p>
I always unplug and store the laser carver when it is not in use. I also put an opaque cardboard piece around it when carving.<br>But agree you need some semiopaque layer to quickly detect if the carved piece is on fire. <br>I carve next to the window, but the idea of an extractor sounds nice. I'm just afraid of forced venting increasing the risk of fire. <br>There is also another issue with loudness. I tried to make a foam base for my laser carver, but it is still loud. I don't know if the full enclosure you suggest will reduce the loudness, also.<br>
<p><em>&quot;Never forget that you can use your tools to make better tools.&quot;</em></p><p>Worthy of being cast in bronze and hung in every workshop. ☺</p>
<p>Kudos to you for bringing up laser safety! I have been cringing looking at some of these DIY laser projects because even though safety is mentioned it never seems to be stressed. ANY exposure of laser light to the retina causes damage be it direct or reflected, high powered or low powered. The small laser pointers, small little bit of damage but the kicker is it is permanent damage and accumulates over time. It may take a hundred hits to the eyeball to notice, but it is still there.</p>
<p>Fully Agree!!!</p><p>Never be passive or careless with any kind of laser device. They may appear to be harmless, but nothing could be farther from the truth. Always use the proper safety glasses that are not expensive.</p>
<p>Excellent cautions. Most also don't know vinyl is also a material that should not be burned it is a variant of PVC and will emit Chlorine gas. GOOD WORK!</p>

About This Instructable

47,517views

265favorites

License:

Bio: I'm an Electrical and Computer Engineering Professor at the University of Kentucky. I'm probably best known for things I've done involving Linux ... More »
More by ProfHankD:Making Your Mini Laser Engraver Safer And Better 3D-Printed Focusing E-Mount Adapter For Ultra-Fast Lenses This Old TARDIS 
Add instructable to: