
Laser Products I Hate - pareidolia
http://www.funraniumlabs.com/2017/08/laser-products-hate/
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vkrm
Site is inaccessible for me, Google cache link:
[https://webcache.googleusercontent.com/search?q=cache:Ylgqkr...](https://webcache.googleusercontent.com/search?q=cache:Ylgqkr90gRUJ:www.funraniumlabs.com/2017/08/laser-
products-hate/+&cd=1&hl=en&ct=clnk)

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StavrosK
With CSS:

[https://www.eternum.io/ipfs/QmNopFQyLda1PeMJsqqPXYSVZxq8i2Xk...](https://www.eternum.io/ipfs/QmNopFQyLda1PeMJsqqPXYSVZxq8i2XkaPgBEmhHdMAdnm/)

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VLM
Consumer lasers will be the spray paint of the next century. One small segment
of the population will see them as an overly expensive way to accomplish tasks
slightly more conveniently than the alternatives, and another larger segment
of the population will use them mostly to trash their environment, leading to
all kinds of weird attempts at legal restrictions.

No one has mentioned the obvious terrorism related issues with lasers. The
worst body counts won't be individual random "makers" with poor coding skills
and their bystanders, or even the cops, it'll likely be, say, an entire
stadium instantly blinded, or really any public location, such as interstate
highway overpasses or airport security lines. I suspect we'll soon have
discussion on the topic of "weapons of mass destruction" as applies to lasers.
Based on past experience, if some Saudi citizens snuck something in to the
stadium (drone delivered?) then blinded everyone attending the Superbowl,
would we invade Venezuela conventionally or nuke Iran?

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rjzzleep
On that note, does anyone have good resources on building laser powered
products? I figured it would make sense to start by reading an optics
textbook. [1]

Something like Building Electro-Optical Systems by Hobbs. First problem is
that I wouldn't even know which ones good.

The next problem I see and which the article touches on is that the wrong
setting might cause irreparable tissue damage. Which by extension means that
making sure that the variance is power must have a bunch of failsafe circuitry
more so than the average meditation eeg startup.

I believe there are reliability test scenarios for electrical equipment in
space, so i assume there's similar things for this use case. Would anyone be
able to point in the right direction?

[1]:
[http://eu.wiley.com/WileyCDA/WileyTitle/productCd-0470402296...](http://eu.wiley.com/WileyCDA/WileyTitle/productCd-0470402296.html)

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analog31
I have Hobbs, and it's a great general book. But it may fall into that fine
literary genre of "explanations for people who already understand things."
Hobbs assumes a fairly advanced understanding of physics and electronics.

You might be able to learn how to make gadgets that work at the prototype
level, but designing a potentially dangerous product is engineering. I don't
know how you do that without working as an engineer for a long time.

Disclosure: I'm a scientist who works in laser product development, among
other things, but not a licensed engineer.

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fest
On a related note- do you know of any books that cover diode laser safety?
Specifically, I'm working on a FMCW laser rangefinder (hobby project to teach
myself more of analog electronics) and would like to know what is the maximum
optical power I should use.

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pjc50
There's actually a good quick guide to this in the article: stick to the laser
pointer classification of less than 5mw.

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fest
I'm more interested in things like: if the diode is on for half the time (50%
duty cycle), can I use 10mW? if I transmit a high frequency chirp with even
less total duty cycle, can I use even more power?

Not that it really matters in my case: I will probably scrap the project
when/if I make a good enough amplifier stage and phase detector for short
range where 5mW should be enough.

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analog31
Well, Hobbs is also the place to go for how to make that amplifier stage. He
has some articles online for photodiode front ends, that are quite
informative.

Admittedly I've never looked into those issues because the gadgets that I've
helped design are all Class 1 -- the system is fully enclosed and interlocked.

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wnkrshm
I work with lasers and we get a yearly security training on staying safe with
lasers (the whole shebang, videos of cow-eyes exploding from diffuse
scattering of a cutting laser, cutting pizza, photos of scars of accidents,
post-trauma photos of retinas etc).

It is indeed terrifying to see how easily you can get tools that can cripple
people without people being aware of the danger.

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avian
I've spent some time in a lab with an optical table and what was probably a 10
mW helium-neon laser. Doors locked when the laser was on, warning signs,
protective eyewear and strict procedures during experiments. And then you go
out and see drunk people at parties with lasers from eBay of unknown power
pointing them at random people. The lab experience made me really paranoid
about anything that involves lasers and I completely understand the author of
this article.

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wnkrshm
Exactly. I've even seen 'party laser' products at dollar stores with moving
diffraction gratings that project patterns on the walls, marketed like a kid's
toy (and I think with a Class 2).

Even worse, the EU norm for lasers has been amended for incoherent sources.
Previously, LEDs had to fulfill certain maximal radiance requirements to not
need a laser sticker. They raised the radiance limit for LEDs by a factor of
100 (so if it was coherent it's about a Class 3 now). I treat bright
LEDs/flashlights like lasers now at close distance.

Edit: (someone could classify a Class 4 diode laser array for heat treatment
as an LED array now (given shitty M __2) and avoid the laser norms altogether,
despite the thing still being dangerous)

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damnfine
Interesting that he compares them to firearms, and all that entails. With
power levels increasing, we may see a viable laser rifle soon, and with it, a
need for a new regulatory structure (or adoption and expansion of an existing
one, atf, etc.) They seem to have many of the same public safety aspects, but
will someone popularize a legitimate 'Sporting Use' for these devices before
they are sold as 'Death Rays to Blind Everyone and Set the World on Fire', And
deemed unsutable for mere mortals to own? I hope so. I guess based on this
article, you could sell a kit without much liability.

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anfractuosity
I wonder how practical a portable laser gun would be, as I'm imagining a laser
diode array would need to be amazingly powerful (I'm assuming much greater
than the 40W version in the video?) and they'd require a very beefy power
source.

It seems diode lasers are up to 60% efficient?

It looks like you can get extremely high power pulsed laser arrays though.

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dhimes
It's not so much the power as the total energy delivered that matters. So, in
that sense, it will depend on the batteries (or whatever storage mechanism
they use) as much as the lasers themselves.

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anfractuosity
Yeah definitely, I can't help but think the power source needed would be very
heavy too.

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rini17
Who makes you unable to help yourself? Say, one watt delivered onto the retina
can do damage very quickly. One AA battery can easily supply that.

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anfractuosity
Sorry I wasn't thinking about a system capable of blinding people, those do
definitely exist though. Also there are devices such as 'dazzlers' which are
intended to cause non-permanent damage.

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dhimes
Yeah, we were talking about something _really_ fun, like being able to melt a
boulder or something. %^)

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atemerev
I don't know, looks like an advertisement to me. Fun, dangerous, barely legal
-- what's not to like?

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microcolonel
Yeah, I don't really see the issue. People play with knives, operate firearms,
use table saws, and cross the street in traffic all the time. The stakes are
high in life, and if you're not careful you might poke an eye out with that
thing, but what fun is a world where everything is engineered to be too dull
to poke an eye out?

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xioxox
Because it's extremely easy to damage other people with lasers. Stray
reflections can easily blind. It's one thing if you're in an enclosed space
only able to hurt yourself, but most of the real world is not like that.

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pdkl95
> Stray reflections can easily blind.

To emphasize this point, since we're talking about a 450nm laser at either
500mW (maybe just barely low enough to hypothetically qualify as Class 3B?) or
800mW (probably Class 4?), any stray reflections could easily cause blindness
_before the eye can respond by blinking_.

Any laser powerful enough to burn or cut is a "why did my eye make a popping
sound"[1], risk, not the " _blink_ oww! that's bright!" that we are familiar
with.

[1] the sound is a spot on the retina _explosive boiling_ after the laser
heated it extremely rapidly past 100C

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microcolonel
Here's a video of a public axe throwing contest with amateur participants, no
backstop, and people directly behind it.

[https://youtu.be/EeiMvKuXs0E](https://youtu.be/EeiMvKuXs0E)

People endanger the public at large all the time, knowingly or unknowingly.
There is no decent world in which acts which merely pose a danger to the
public are illegal before they cause that danger.

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jerf
People instinctively understand the risks of throwing things, even sharp and
heavy things. People do not have an instinctive understanding of the risks of
lasers. They may both be dangerous, but that does not mean the two levels of
danger are the same.

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MarkMMullin
Hmmm - one serious thought - 'makers' thinking of playing with 1+ watts should
also seek out videos of what happens to normal consumer and better non laser
grade optics when used as focusing or steering elements - I knew of a lab that
basically had very fine powered optical glass blown into the nearby walls (it
was empty during the test) - and one less serious thought, from the same lab
where I first encountered this sign... "Do not look in the laser with your
good eye" :-)

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unwind
The Cubiio (which is at the focal point for this hard-to-browse article) also
gets the AvE treatment here:
[https://www.youtube.com/watch?v=d7WmUXtizEA](https://www.youtube.com/watch?v=d7WmUXtizEA)
[video]). Not so good PR there, either.

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abakker
I've got a 4x8 CNC router with a small 4W laser diode that I can add on for
light engraving work. Discussions of safety, protective eyewear, interlocks,
shielding are all very valid. the stray reflections cutting wood in open air
mean that there is significant scatter. The other day I attempted to engrave
cork and found the scatter to be terrible.

BUT, all of that can be managed with shielding, eye protection, and walls.
When the laser is on, I've rigged mach 3 (CNC control) to turn on some lights
at the top of my staircase so that nobody comes into the garage without
protective eyewear. It is absolutely possible to be safe without also limiting
all your freedoms. In general, safety standards and workshop use-cases are
well aligned, and if safety is too much work then a lack of safety is not
about freedom, it's about laziness.

AvE has also taken a crack at Cubiio, and I think it is worth repeating some
of his points, and my own observations here.

1\. Diode lasers for engraving are VERY sensitive to focal length changes. If
my surface that I am engraving changes more than 1-2mm in height, I try to
compensate for that in the engraving tool path. My minimum line width is .01"
with the laser/lens combo I have, and if I am out of focus even .125" (3mm),
the line width will probably double.

2\. many materials reflect terribly while cutting. Especially pre-finished
light colored woods like maple. There is practically no way to avoid this. If
I cut those I'll often end up with uncut areas in the piece because 100% of
the beam ended up scattered, and didn't manage to burn the piece at all.

3\. the idea is very tempting. It would be very nice to have this
functionality, but, for the average maker, I think you would be pretty unhappy
with the power this can make. I frequently want a LOT more than 4W, this
appears to be about 1/4 of that. Most commercial systems from Epilog start at
20-40w. The Cubiio would probably produce shallow, uneven cuts at very slow
feed rates with really long run times to produce anything useably deep. If you
ran it at faster feed rates it would probably produce a laser engraving so
shallow that it would rub off.

4\. I want their app. The ability to turn scanned art into vectors for G code
is something I would pay for. AFAIK there is NO good commercial solution for
this. I have tons of line art that I would love to laser engrave but have no
way to produce simple paths from it.

Edit: this is the laser I have -
[https://jtechphotonics.com/?product=3-8w-laser-and-2-5amp-
sa...](https://jtechphotonics.com/?product=3-8w-laser-and-2-5amp-safety-
compliant-driver-kit) \- I can vouch that it is well made and the vendor is
great to work with - he assembles these himself and takes safety seriously.

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agumonkey
this guy uses an engraving laser with copper film to quickly make traces/PCBs
[https://www.youtube.com/watch?v=GEABTyNZv1k](https://www.youtube.com/watch?v=GEABTyNZv1k)
[french]

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wiredfool
So in addition to the Class 1-4, there should be Class "What remaining eye?"

