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Dave Graf
01-17-2011, 11:18 AM
Hi Everyone I am Judy Daves wife I have a question or more of a poll :confused:

My husban just got a Laser engraver about a week ago and I told him he should get laser safety glasses
I found them on the net for around $50 he said if you look at the youtube vids etc you will see no one wears them Hmmm MEN ..

So here is the question how many of you use them and why or are these machines safe to use with out them????

No Birds were hurt in the photo.. But I think he needs glasses also..

Mike Null
01-17-2011, 11:56 AM
I've been using a laser for 13 years without laser safety glasses--just my regular tri-focals. No problems.

But if you think he should have them then if I were he I'd go out and get a pair.:)

Dan Hintz
01-17-2011, 12:20 PM
Judy,

Here's an answer, as well as a reason. If it's a CO2 laser (as your picture makes it appear to be), glasses are unnecessary as the glass/plastic window in the lid (usually clear, but any color will do) absorbs all of the radiation. If it's a fiber laser, the lid should be designed to do the same thing... usually this is an orange color (if it's clear, it's a bad design and you should be wearing appropriate eye protection).

Richard Rumancik
01-17-2011, 12:47 PM
Hi Judy and Dave

Most of the systems on this forum are closed boxes (with acrylic or glass lids) and many are classified as Class IIIa. The Class I is for a fully enclosed laser with no risk of the CO2 laser beam exiting the box in normal operation. But most of these lasers have a red-beam pointer, which is active with the lid open. So one could potentially place their eyes in the red beam path. This bumps the laser system into Class IIIa (as a simple laser pointer is often Class IIIa on its own.)

There are interlocks to prevent the CO2 laser tube from operating if the door(s) are opened. But sometimes these interlocks are defeated for long parts etc.

If the access doors are always closed, it is generally accepted that glasses are not essential. But with open doors and for service work (e.g. beam alignments) it would be a good idea to have some type of safety glasses or goggles.

For bed systems (fully open table) glasses are required at all times and the room must be interlocked so visitors cannot enter while the laser is in operation.

I am not certain what kind of laser you have. Is the Morn laser a rebranded Chinese laser system?

Michael Hunter
01-17-2011, 1:05 PM
Does the husband wear eyeglasses anyway?
Since both acrylic and glass (the materials most likely in standards eyeglasses) absorb the energy from CO2 lasers, then the eyeglasses by themselves would give good protection.

The best protection of all is to keep the laser beam inside the box by closing the lid and NOT defeating the interlocks.

Scott Shepherd
01-17-2011, 1:15 PM
Just to add to what Richard (and others) said. He should NEVER look at the beam if the doors are open and it's cutting. If the doors are closed, there's no risk that I am aware of.

Dave Graf
01-17-2011, 1:32 PM
This is Judy responding. Yes, it's a re-branded Chinese laser without interlocks on the door! I'll make sure to have him keep the door closed.

Thanks for ALL of the information! My husband wears glasses so I understand that should also be helpful. This is all new to me so learned a lot from your responses. Thanks again.

Gary Hair
01-17-2011, 1:39 PM
Since both acrylic and glass (the materials most likely in standards eyeglasses) absorb the energy from CO2 lasers, then the eyeglasses by themselves would give good protection.

I'm not sure you are right about glass absorbing energy from co2 lasers - if so then how could a lens work?

Gary

Dan Hintz
01-17-2011, 2:33 PM
I'm not sure you are right about glass absorbing energy from co2 lasers - if so then how could a lens work?
CO2 wavelength lenses are (usually) ZnSe (Zinc Selenide), which is about 98% transmissive to that wavelength. Glass of most any type is highly opaque to that wavelength (by roughly a few hundred microns of travel, you can consider it 100% opaque).

Gary Hair
01-17-2011, 2:39 PM
CO2 wavelength lenses are (usually) ZnSe (Zinc Selenide), which is about 98% transmissive to that wavelength. Glass of most any type is highly opaque to that wavelength (by roughly a few hundred microns of travel, you can consider it 100% opaque).

I learn something new every day, even if it's just the fact that I don't know everything...

Dan Hintz
01-17-2011, 6:33 PM
I learn something new every day, even if it's just the fact that I don't know everything...
If I didn't know it before, I'm certainly learning it as I write my book... it's amazing the sheer amount of info that's out there, and a few key snippets have altered my thinking towards certain subjects.

Russell Ludwick
01-18-2011, 12:22 AM
I don't think you really need them, but I went ahead and got the laser ones anyways since I need a good pair of regular safety glasses. They aren't that much more expensive and at least you got the piece of mind.

You can get them on mcmaster for under 40 bucks
http://www.mcmaster.com/#laser-safety-glasses/=amzpe9

Bill Cunningham
01-18-2011, 11:00 PM
When Epilog sent me my new tube a few years back, you have to fire the beam with the lid open to align it. They included ordinary low cost plastic safety glasses to wear and block any reflected or random rays while the lid was open. You can probably buy a decent pair for 5-10 dollars in any hardware store. They would have to be pretty special before I would spend 50 bucks on a pair of safety glasses..

Dave Graf
01-19-2011, 12:15 AM
Dan:
Just have to say Great answer I love to experiment so I tested the theory Of Opaque I put a paper in front of the last mirror fired the laser puff hole in paper
put an old pair of Glass eye glasses just in front of the paper fires the laser several times just like hitting a brick wall no puff no hole ... It's opaque no light ( harmfull Light Pased thru)

Did it again to see how long it would hold back the light from a direct hit 4 seconds at 50w (Shatterd) the glasses and then a hole in the paper .. so I guess I will not delibertly put my eye at the end of the laser !!!!!!

Test with plastic safty glasses the same except 1 sec burned a hole got the paper

Conclusion Radom rays will not get thru clear plastic or glass