Its very greeeeeeeeen

[rszemeti]

Simple fact is, did you go blind or burn your fingers? no? well in that case you clearly took adequate precautions

That is a nice little laser there, fun to play with without being scary. Those sort of power levels, YAG is not that dangerous on the skin, you can usually get your finger out of the way without damage ... CO2 tends to leave a nasty burn though at around 60W, no matter how fast you move your hand. Unless you are particularly stupid, you can't really come to mutch harm with a 60W YAG though ...

This baby ... well, you almost certainly want to keep your fingers out of the way of this one ...

or at least practice moving your hand really quickly. For anyone that cares, power output is around 4.5kW, pulls 250A a phase off the 3 phase when its running ...

[dsli_jon]

Very close to the metal fire escape! I think 40w is a bit too much for me.

Warn't a fire escape - was an overhead-canopy frame, and no-public were present in this particular back-area of the venue.. additionally, we went-out on the sidewalk, on the other side of the wall, there, to make sure there were no spurious / dangerous-reflections, and there were none...

Usually, it's better to ask questions and get answers - especially when, here, they are never-more than a pm or post-away - than try to extrapolate and belly-flop...

@ rs - re: "Those sort of power levels, YAG is not that dangerous on the skin, you can usually get your finger out of the way without damage.." ..Uh... I opin you should 'better-qualify' that statement, considering the 'audience' here are not all seasoned Ops with high-power systems.. last thing we need is some kid buying a LS off FleaBay, and burning his eyebrows-off (..or worse..) with the 1064, and saying '...well, I read on PL it was 'OK'... ...Yes, unfortunately, there *are* those 'that dumb'...

ie: http://www.youtube.com/watch?v=t65_JJrLFZ8

cheers...
j

[rszemeti]

shrug, why worry? it will make an amusing "darwin awards" entry if nothing else ... you can't save dumb people from hurting themselves.

There is a tendency to make these things out to be more dangerous than they are. Providing you don't go looking into the beam, have you ever heard of anyone beign hurt by a 60W YAG?

I think there are a lot of people who like to imagine their 200mW lasers are "powerful" (they aren't, even though it said so on the box at the disco equipment shop) and thus anything 10 time more powerful must be "dangerous" (nope, sorry) ... Sure, some retard will go and look down one one day, but they would probably have chopped their fingers off in something sharp if they weren't doing that, so what?

Knitting needles are quite dangerous if you poke yourself in the eye with one .. but I wouldn't call them dangerous. Circular saws can off your fingers quite easily, but you can buy one in every hardware store. 60W laser ... I've never heard of anyone getting a nasty burn off one, but they are quite heavy .. I suppose you might drop it on you toes?

hint: do not stare into beam with remaining eye.

[Psi]

If a reflect can cause permanent eye damage then it's dangerous in my opinion.
So anything above 100mW i would consider dangerous.

How dangerous something is isn't just about the item itself. It's also to do with how knowledgeable the general public are on the subject.
Everyone knows not to stick their finger into a rotating circular saw, but even sensible people probably wouldn't think about reflections when playing with a laser.

[rszemeti]

Please provide list of people you know who have permanent eye damage from 100mw laser toys.

I think you are making it up

[dsli_jon]

shrug, why worry?

It's not 'worry', it's called education, because, remember (..as, apparently you missed it the first time..) - "..the 'audience' here are not all seasoned Ops with high-power systems.." ..if this forum was just 'the water-cooler' for only experienced laser-engineers and pros, I wouldn't have felt to need to make the comment, dig?

60W ..(and in a LS, the 'more-likely' unit, someone from this forum-pool might end-up with, it's more like 85-130W of 1064..) is plenty capable of starting a wicked-fire, instantly... *that's* something an inexperienced-one needs to know, not only that you-feel 'it's not that dangerous on the skin'... why, then, are there 'DANGER' stickers, relative to eye and skin-exposure, mandated on the units? Cause they're just fearmongering fascists, subliminally vying to take away all your freedoms?

...you can't save dumb people from hurting themselves.

No, you can't - but aren't you glad that someone cared enough about you to *try*? ...You see, we're all 'dumb' till someone else teaches us... (myself, included... ...And look how well you turned-out, because others gave you some effort, eh? Now, yes - once taught, there are certainly those who will ignore the good-advice / education, and indeed, those people will need to 'learn again' by blowing an eye-out or setting their sweater on fire, while still in-it, etc, etc... But, the educated should at least *try* to educate, and then set a 'good example'... not say - unqualified - that '60W YAG is not that dangerous on the skin'... sorry, that's - imo - "Dumb".

I call 15-love..
j

[White-Light]

Please provide list of people you know who have permanent eye damage from 100mw laser toys.

I think you are making it up

http://www.laserist.org/2009-07_Belgian-incident.htm

2x people with Permanent eye damage from a pointer in the 200mw+ range pointed from a distance.

[rszemeti]

Whatever, 100W will not create a "wicked fire instantly" ... unfocused, it will cause gradual charring of wood. Having personally got my hands in the way more than once of 100W class YAGs, I can tell you that its no worse than touching something hot and providing you react, no harm is done.

100W of CO2 would be a different matter, someone flicked a focused 30W CO2 across my hand once and it left a sizzled mark, but there again, I know many many people who operate multi-kilowatt CO2 lasers cutting steel with the protective barriers down, and regularly have reddened faces from the flash during the piercing cycle, but appear not to suffer any long term effects. When aligning larger CO2 systems, the standard procedure is to place a piece of card in the beam path, and fire a single pulse, with enough energy to leave a charred mark on the card ... I find about 7ms at 1500W is about right for 30mm beam diameter ... try that with YAG and it doesn't even make a mark.

Perhaps if 60W of YAG is so dangerous, you can explain why the guy in the video burning holes in a titanium tweeter dome while casually handling it beam-on, has not gone blind or suffered any eye damage?

No, you can't - but aren't you glad that someone cared enough about you to *try*?

Honestly? I'm pretty sure no one did. I learnt from experience and experimentation, plus some universtiy level physics As a youngster, I played with electricity and learnt not to touch the sparky bits. I played with petrol and pressurised burners and learnt not to get in the way of the flames. I played with explosives, and learnt to be far enough away for when it went "Boom" (unlike my friend Roger, who learnt that you can't have your arms sewn back on, but thats another story) End of the day, best way to learn about stuff is to have a go. Providing you are not putting others at danger, why worry?

Not only do I believe people should be allowed to play with dangerous things, I think people should play with dangerous things and occasionally get hurt. Theres nothing like the smell of burning flesh and a missing bit of skin to bring the lesson home in a practical manner.

The purpose of life is to get to the end with everything worn out, not unused and in perfect condition!

[Psi]

Perhaps if 60W of YAG is so dangerous, you can explain why the guy in the video burning holes in a titanium tweeter dome while casually handling it beam-on, has not gone blind or suffered any eye damage?

In the video the laser wasn't being fired at him, it was directed into its own metal housing area which would have been designed for safely stopping a high power laser beam without any reflections.
Also the beam was IR, things which are reflective to visible light are not necessarily reflective to IR.

[rszemeti]

Oh, and how reflective is titanium to 1064nm IR then? (you can go an look it up, for kicks, compare it to gold, the result will surprise you)

there will have been considerable splash off that (you can see as much in the video camera), and they guy was clearly observing the target area while holding the bit of Ti, but, no one was hurt ...