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How I got my laser eye injury

funraniumlabs.com

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Re: How I got my laser eye injury

#351

Post by eru »

ljf wrote: post #311
eru wrote: post #298

Earlier quoted context omitted.

> This seemed like a wild claim (2500 watts for a tea kettle!? As much as a microwave oven in full blast?) so I looked it up. Wow. Almost all household appliances that heat (and specifically heat food or water) will operate at the limit of what your house can supply. So that's about 1800 Watt in the US and about 3500 Watt in most of the rest of the world. It's only natural that you see almost any (heating) appliance…

I found it odd that in the US most home brewers don't use electric, but as you say they are limited by the elements they can use. Here in the UK, my home brew beer set up has a 3000w option - great for boiling 25 litres of water/wort - that said it came with a EU plug with some sort of 'fancy' UK plug convertor. After about 4 years the plug started to get so hot that it melted a socket or two - I found that inside th…

> I found it odd that in the US most home brewers don't use electric, but as you say they are limited by the elements they can use.

Yes, but you still see electric space heaters. And they essentially all also have the same wattage: the limit of what they can get.

Re: How I got my laser eye injury

#352

Post by fasa99 »

notelectronic wrote: post #119
DannyBee wrote: post #17

So I laser weld, and beyond my own PPE, interlocks (gun won't fire if it's not touching metal, etc), the most important part of the whole setup is laser safety curtains. Because it's a 2500 watt laser, if i didn't have laser safety curtains , the relections/etc could very easily blind someone at a fairly long distance. The NOHD (nominal ocular hazard distance) is something like 10km (2500 watt laser, 0.06mm spot size…

I get laser safety curtains, but what do you do for reflections off the ceiling? Asking because our makerspace was recently donated a fiber laser welding unit and we don’t yet know best practices for not blinding our membership short of building a completely enclosed separate room for it with door interlocks.

What I do to match my lazer curtains is I hang a lazer tapestry off the ceiling to block all the lazers. I don't do lazer welding but I have lazer scissors and lazer axe which it is still useful for

Re: How I got my laser eye injury

#353

Post by jtwaleson »

meindnoch wrote: post #347
jtwaleson wrote: post #343

Earlier quoted context omitted.

I’m confused. This is true from every angle from which you look at the wall right? So there has to be quadratically less reflection than e.g. a mirror, but still a lot more then a completely black surface.

The inverse squared falloff from a diffuse surface is not enough to prevent eye damage if you're in a regular-sized room, and playing with a class IV laser, or even some class IIIb lasers (depending on the distance, and the duration).

Got it, thanks!

Re: How I got my laser eye injury

#354

Post by beAbU »

cesarb wrote: post #344
beAbU wrote: post #276

Earlier quoted context omitted.

Not just UK, the whole world except North America and Japan. South african plugs are rated 16A @240V. Thats a safe 3.5kW at each and every plug socket in the house.

> Not just UK, the whole world except North America and Japan. Brazil is also an exception. The standard socket is only 10A (with a 20A alternative for things like air conditioners), and the voltages vary depending on the city (and the building, and location within the building); you might have 110V, 115V, 127V, 220V, 230V, and perhaps others I have missed (I went in more detail about it at https://news.ycombinator.c…

So it's pretty normal for a "230v" plug to actually be anything between 220v and 240v. Voltages fluctuated pretty wide depending on location. It's all down to the loca transformers.

But mixing 100s of volts with 200s of volts sounds mad. I presume you had the special plug for your 200 range outlets? Does Brazil also have split phase AC like the US?

Re: How I got my laser eye injury

#355

Post by Doxin »

bleakenthusiasm wrote: post #279
sersi wrote: post #146

Earlier quoted context omitted.

Should I be concerned about the lidar in my dreame robot vacuum (L10s ultra) and my 3 years old whose head is closer to the ground than me? I never thought about it before but you'r comment worries me.

So going by what they aimed for in building the laser: No. The nominal power and wave length of all of these appliances is less harming to the eye than going outside on a sunny day and forgetting your sun glasses. The issue here I guess are malfunctions or rather cheap products with bad calibration. For total safety you'd have to get someone to measure input and output of the laser. I'd love to reassure you about som…

Keep in mind that LIDAR is moving lasers too, which are allowed to be higher power but should have an interlock that turns the laser off when it stops moving.

I'll leave the extrapolation on how that could go wrong to you.

Re: How I got my laser eye injury

#356

Post by sersi »

bleakenthusiasm wrote: post #279
sersi wrote: post #146

Earlier quoted context omitted.

Should I be concerned about the lidar in my dreame robot vacuum (L10s ultra) and my 3 years old whose head is closer to the ground than me? I never thought about it before but you'r comment worries me.

So going by what they aimed for in building the laser: No. The nominal power and wave length of all of these appliances is less harming to the eye than going outside on a sunny day and forgetting your sun glasses. The issue here I guess are malfunctions or rather cheap products with bad calibration. For total safety you'd have to get someone to measure input and output of the laser. I'd love to reassure you about som…

Hmm my kid does like to chase the robot.

It seems rather difficult to measure the laser input power though. Apart from trying to reverse engineer the robot?

I guess I'll just make sure that it's not turned on if my kid is awake at home.

Re: How I got my laser eye injury

#357

Post by JansjoFromIkea »

CamperBob2 wrote: post #144
JansjoFromIkea wrote: post #46

Lasers absolutely terrify me now; I impulse bought a 2w lasercube in 2020 for next to nothing (circa $200) and once I started reading up on it I was pretty appalled how easy it was to buy. This was a fairly expensive RRP laser with some level of protection and stuff around it, the fact you could buy pens capable of pretty significant damage on ebay for way less where people wouldn't even grasp just how dangerous the…

Why not just wear the appropriate goggles? You don't have to be afraid, you just have to be careful. Of course, being careful means considering the possible presence of subharmonics, and buying your goggles from legitimate suppliers rather than unpronounceable Chinese brands on Amazon or eBay.

I will when I have appropriate goggles; it looks like they'd cost not too far off what I paid for the laser itself though?

Re: How I got my laser eye injury

#358

Post by rcxdude »

I went to a talk by a guy who worked on fibre lasers. Shortly after he showed a video demonstrating how it would work its way through a brick wall in about 20 seconds, he suggested that they might one day be commercialised by selling them as tools for people to slice up tree branches in their backyard, seemingly without any awareness of how terrifying a prospect this is.

Re: How I got my laser eye injury

#359

Post by msrenee »

SonOfLilit wrote: post #342
msrenee wrote: post #285

Earlier quoted context omitted.

Some sharks have to swim to move water over their gills. Not even close to all of them and it's not due to their heartbeat being connected to their swimming. https://www.britannica.com/story/do-sharks-really-die-if-the...

Thanks. In my defense, I heard this from my diving instructor who is a marine biologist.

It is a thing. It's just not as universal as people try to claim. There's a lot of biology in the marine world. No one can be an expert on all of it.

Re: How I got my laser eye injury

#360

Post by mike50 »

relaxing wrote: post #7
zoky wrote: post #3

I’m not saying it didn’t happen as described, but this really kinda reads like the “Bald eagle named Albert Einstein flew into the classroom” copypasta…

The sales guy set up the entire rig on his own? And no other engineers in the lab stopped to ask what he was doing? I know some places have poor safety culture, but this is a “laser company”. Basic laser safety should be drilled into them from day 1 and every day after. When I worked in an optics lab, we had interlocks on the doors that switched on with the power supply running the experiment and a sign outside indic…

The structure of the industry is many small companies that make one specific laser based on the owner's PhD research. These companies cannot have the perfect safety culture simply due to staffing numbers.
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