Safety Concerns: Is the Pro right for me?


I have kids who are 4 and 6 years old. I plan to set up our Glowforge in a spare room in our home. I’m currently deciding whether to downgrade my order from a Pro to a Basic due to concerns about safety.

The room that the GF will live in has a standard household lock, and I’m open to installing a keyed lock on the door instead of the existing lock.

I do plan to supervise the GF when it is running, to put up a sign, and to provide appropriate eyewear for anyone who is in the room with it when it is running with the pass through slot open (or all the time, depending on how secure the pass through slot is).

I would really like to see images of the Pro that show:
The pass through slot in action, close up
The pass through slot at rest, close up, with any locks, etc. that will be included or available when the GF ships.
Some sample aftermarket devices that would dependably disable the pass through slot when it is not in use. (Would these be sufficient to make safety eyewear unnecessary?)

I would also like to see a video that shows a “high risk” activity from the standpoint of the laser beam’s leaking into the room, such that safety eyewear is actually protecting users.

I appreciate any/all help in sorting out the actual risk of having a Pro in my home, versus a Basic GlowForge.



I can’t say for sure without seeing one in person, but it might be pretty easy to essentially lock out the pass-through slot in a childproof way.


I would also advise pulling the power plug and putting it up on a high shelf. That alone makes safety go a long ways.

With a 4 year old, your primary concern will likely be making sure to pull all the coins and whatever else the tyke jammed through the hole out of the tray before any cuts.

Glowforge official won’t be able to say too much to reassure you on the passthrough and laser safety. Lawyers would only allow them to scare the crap out of you.

The beam can only get out if it reflects off of something. If you do not put anything reflective in the machine, the beam cannot possibly do anything to anyone outside of the machine.

If the beam DOES reflect and fire out of the machine, it will be a straight line path from whatever you had in there which is reflective, through the passthrough, and further on. So unless the reflection happens RIGHT at the passthrough, it will be a beam in a very narrow band, staying at essentially the same height as the passthrough opening.

So, place your machine so that the passthrough opening is not anywhere between lip and top of head height for anyone, and you are likely well set for non-goggled safety.

Even if you accidentally put something reflective in the bed, short of a hard drive disk, you are looking at a very poor reflector, so the beam power will be greatly diminished. The laser is also very likely moving along at a decent speed, so only reflecting for a very short period of time.

In summary: The danger is real. But minor. If you are paying attention to what you are doing, you have nothing to worry about. This is not a saw blade spinning out in the open where having a kid in the vicinity is tragedy waiting to happen.


Great points about the power supply and table height.

I do get that the GF folks have to err on the side of extreme caution in everything that they tell us about the device. And I’ve read up a bit on the rules and regs for Class IV lasers in workplaces, which have scared me thoroughly.

My gut says to get the Pro, and my anxiety says to get the Basic.

I really appreciate your taking the time to offer some practical precautions and some real world experience. Super helpful.


Is your spare room big enough to actually use a pass-thro. You would need space front and back and for the materials. (I’m in the UK and there are not many rooms here that would work!)


@sqw makes a good point about checking for practical measures as well.

The passthrough slots are pictured in my Maker Faire thread

The openings are about 3/8" wide, so kid fingers could fit through. My assumption is that the holes you can see inside the casing above the front passthrough are where the flap would attach. You could wedge a piece of thin metal between the flap and honeycomb and make it impossible to push through at all. And a larger chunk of metal/wood on the back side would secure that one as well (though having the whole Forge backed up against a wall also locks that one down nicely. Just relocate when actually using the pass through)


Remember, when jacobturner discusses the reflective surface that is reflective to the wavelength of the laser which is not the same wavelength as visible light. Just because it’s shiny doesn’t mean it will reflect and vice versa for dull objects in visible light.

A secure table is never a bad idea. If they climb or pull on stuff, the glowforge falling on them may be the biggest risk.

They have to login to your glowforge account to send a file to the glowforge. It’s my understanding you cannot just “turn on” the laser…but kids are awesome at ferreting out passwords.

Something I don’t remember posted in any safety related threads is the “familiarity breeds complacency which leads to poor safety practices.” The reason refrigerators in areas that handle blood and bio-hazards have signs on them saying “don’t place food in here” is because people put their lunch in them. People with years and years in college and who technically know better. Now take a teenager who has been using this tool since they were four or six. Personally, I’d be more concerned about a teenager circumventing the lid’s cutoff switch to laser with the lid open than the series of events that have to occur to blind themselves via the pass through slot, but I’m not a parent. And even then, the laser would be orders of magnitude safer than traditional power tools. Or the Internet.


When you’re talking about kids (and grownups) it’s not just the IR that’s a concern. The burn spot is a point source of really intense visible (and probably some UV) light that’s going to be no fun if you stare at if for a long time. Probably not actually damaging, but really long afterimages.


I know that any torch that consumes oxygen produces UV, so even though atmospheric oxygen content is low, I would expect the laser to generate a degree of UV.
If I am not mistaken, it is the UV exposure over a lifetime that produces cataracts, so it takes a lot of exposure.
Nothing to be afraid of, just be aware that the effects are cumulative and irreversible.
I’m pretty sure the glass lid on the laser eliminates any UV exposure, but as @paulw pointed out, probably wouldn’t hurt to view through sunglasses if staring at the focal point for an extended period (as I’m sure I will be).

What about it @smcgathyfay? Do you see little residual green dots after watching a file print?


There won’t be any aftermarket devices until after the GF ships. From looking at some of the pictures and reading some of the descriptions, it sounds like there will be no locks built in to the GF for the passthrough slot.

That being said, I wouldn’t be surprised if passthrough locks show up on the Catalog really quickly.

If all you are worried about is blocking the potential reflections, that shouldn’t be too difficult. Heck, all you really need is a slot on the table your Glowforge is on to place a plank of wood that can cover the passthrough.


Nope…after 16 years, my eyes are just fine.:grinning:


I say treat it like the knives in your kitchen drawer, or the hatchet in the tool shed. Educate them on the dangers and proper use, keep it out of reach to tiny ones, let them use it under supervision a whole bunch in the beginning so they lose interest quickly.


We’re hard at work determining the right warnings and cautions for the Pro, so I’m not going to speak out of turn and say something that may be proven incorrect or inadequate. I will say that I have twin 7-year-olds at home and am planning similar precautions as you describe for our home Glowforge Pro.

I will note that UV is blocked by the glass.