The Home Made Beamstop

[Crazlaser]

So lately I've been doing all sorts of burning and focusing experiments with lasers, and it's been too cold outside to be there comfortably for long. So I've been using some of my lasers inside more. I usually mount them in the clamps and put them on tripods.
So I decided to make a homemade beam stop to prevent things from being scorched and to set up a controlled laser environment.

I constructed it out of a cubical cardboard box. Then placed a sheet of aluminum foil at a 45 degree angle inside the box, so laser light entering the 2 inch whole I cut in the side would be diffused by the foil and reflected downward. It works great and neither the foil nor cardboard get hot when used at 5 foot range. Even a three watt 445nm laser directed point blank at the stop causes no damage.

Here are some pictures.

 

[diachi]

Looks like it does the job, but seems like a fire waiting to happen...

 

[GSS]

I'm sure it works but when I see the word "foil" and "lasers" and "cardboard" together

 

[Crazlaser]

Looks like it does the job, but seems like a fire waiting to happen...

You know, I'm glad you said that because I didn't even think of that. Would an aluminum box help you think?
Or galvanized steal sheet box?

 

[GSS]

I use a 12"x12" ceramic floor or bathroom tile spray painted flat black on its non glazed bottom side and siliconed it to a 10" round by 3' long mason tube for setting posts.
The tile keeps it from rolling..and like I had posted before it helps with room glow when using a decent powered 532..

 

[diachi]

I use a 12"x12" ceramic floor or bathroom tile spray painted flat black on its non glazed bottom side and siliconed it to a 10" round by 3' long mason tube for setting posts.
The tile keeps it from rolling..and like I had posted before it helps with room glow when using a decent powered 532..

Yep good suggestions, other options include bricks, cinder block, black anodized aluminum plate, black anodized heatsinks and so on.

You know, I'm glad you said that because I didn't even think of that. Would an aluminum box help you think?
Or galvanized steal sheet box?

Yes, seeing as steel or aluminum isn't going to catch fire if you accidentally leave the beam on it.

 

[Crazlaser]

I use a 12"x12" ceramic floor or bathroom tile spray painted flat black on its non glazed bottom side and siliconed it to a 10" round by 3' long mason tube for setting posts.
The tile keeps it from rolling..and like I had posted before it helps with room glow when using a decent powered 532..

Thanks for the suggestions. I'm more looking for a beam trap rather than a stop I suppose. I like the idea of it entering and being diffused on a semi reflective metal surface rather than being absorbed by a brick.

What about a metal panel in front of the box as suggested by my dad. I'd still rather have it be completely metal. I have access to lots of sheet metal tools but I'm feeling too lazy right now to build a box myself.

 

[lasersbee]

Yeah... I'd stay away from anything flammable or refective
as material for a Beam Stop. We use a satin black Anodized
Aluminum sheet bent at a bit more than 45 degrees as our
Beam Stop.

Jerry

 

[Crazlaser]

I've stopped using the cardboard beamstop because of......on my patio......Can't quite say that stopped a three watt laser beam....good thing is I had a hose nearby.

 

[ElectricPlasma]

I do the same as most the others, I've got this scrap piece of black alu and it sucks up all the light from the laser dot. It works great, better off than reflecting the beam into cardboard.

And much, much, better off than starting a fire.

 

[RB astro]

I use a large (30cm²) *dull* dark grey/black ceramic tile as a beamstop.
Does not reflect the beam.

Works a treat.

RB

 

[Encap]

I've stopped using the cardboard beamstop because of......on my patio......Can't quite say that stopped a three watt laser beam....good thing is I had a hose nearby.

When I first saw your OP I thought Rx for disaster/accident looking for a place to happen. A beam-stop material should not be combustible.

Did you actually expect a different result using reflective and flammable materials with a laser powerful enough to burn cardboard ?

It could have been worse, I guess----used indoors and not extinguished, house burned down or apartment fire--people hurt etc.--someone could have mimiced what you did/suggested and had bigger more serious problems.

 

[Crazlaser]

When I first saw your OP I thought Rx for disaster/accident looking for a place to happen. A beam-stop material should not be combustible.

Did you actually expect a different result using reflective and flammable materials with a laser powerful enough to burn cardboard ?

It could have been worse, I guess----used indoors and not extinguished, house burned down or apartment fire--people hurt etc.--someone could have mimiced what you did/suggested and had bigger more serious problems.

This was a controlled experiment on my patio with a hose nearby to see if the box would combust if the beam was held still from a distance. I was just trying to see the actual dangers of it. I appreciate the concern though!

 

[lasersbee]

I've stopped using the cardboard beamstop because of......on my patio......Can't quite say that stopped a three watt laser beam....good thing is I had a hose nearby.

Luckily it was outside and a hose was nearby...
Glad to see you know it was a Facepalm event...:yh:

Jerry

 

[Crazlaser]

Yes. After Diachi mentioned it could be a fire hazard I took it out back on the patio to see how easily it really could ignite. Answer is very easily. Only needed about 25 seconds from 8 feet to have a flame and by one minute the box was engulfed.

Hey Sean, I used the silver series I got from you. That's my favorite laser by the way.

 

[RB astro]

Only needed about 25 seconds from 8 feet to have a flame and by one minute the box was engulfed.

So, it did stop the beam.... in the end.... :crackup: