Buying: Beam Dump

[Trevor]

I've come to the conclusion that I need a beam dump, a la this one. Do any of you have a beam dump around that you want to sell or the ability to machine one and anodize it black or put a durable matte black coating on?

Tall order I know, but with the people around here, it's worth a shot.

-Trevor

 

[daguin]

That's the one I have. It is invaluable. Good decision

Peace,
dave

 

[Trevor]

That's the one I have. It is invaluable. Good decision

Peace,
dave

1.5W is hard on just about anything I put it on. ><

Edited the first post - I don't have my heart set on that one, I just need a beam dump.

:thanks:

-Trevor

 

[ZRTMWA]

You could try to use two cinder blocks. Lay one down flat in front of one behind it on its side. Spray paint the whole contraption black with high heat paint (i.e. engine enamel, stove paint) so the paint won't burn off when you use higher powered lasers.

These are all my own musings and there is no guarantee that these methods will work but they will sure save you a heck of a lot of money lol.

 

[aXit]

Plenty of people with lathes around that could do it.

You could anodise it yourself, lots of guides around, including a nice one over on PL.

 

[daguin]

Plenty of people with lathes around that could do it.

You could anodise it yourself, lots of guides around, including a nice one over on PL.

You're gonna want the interior to be non-reflective. I believe that an anodized surface will still give you too much "back splash."

Peace,
dave

 

[Trevor]

You're gonna want the interior to be non-reflective. I believe that an anodized surface will still give you too much "back splash."

Peace,
dave

I figured if the inside of the dump is properly shaped, the anodized surface will still reflect less than just having the beam terminate on a black object (which is my currently lame system ><). I guess I'd have to experiment.

-Trevor

 

[HIMNL9]

I figured if the inside of the dump is properly shaped, the anodized surface will still reflect less than just having the beam terminate on a black object (which is my currently lame system ><). I guess I'd have to experiment.

-Trevor

Yes, usually the internal shape is designed for minimize te possible reflection to the output, or at least, for make the beams bounce so much in the inside, before become reflected again to the output, that the more possible energy is adsorbed from the black matte surface and converted in heat ..... like in this way:

Considering that the internal surface is usually sandblasted and then anodized opaque, it can have an absorption capacity of 95% or more, and that a beam correctly pointed can bounce inside 6 to 9 times, before re-bounce to the exit .....

As example, considering a 10W beam that bounce also just 4 times, loosing 95% of its energy in each bounce ..... 10-95%=0.5 > 0.5-95%=0.025 > 0.025-95%=0.00125 > 0.00125-95%=0.0000625 ..... when it come out again, it's a halo of 6.25 microwatt (a halo, not a beam, cause the inside surfaces are matte, not speculars) ..... safe enough, imho

 

[daguin]

Yes, usually the internal shape is designed for minimize te possible reflection to the output, or at least, for make the beams bounce so much in the inside, before become reflected again to the output, that the more possible energy is adsorbed from the black matte surface and converted in heat ..... like in this way:

Considering that the internal surface is usually sandblasted and then anodized opaque, it can have an absorption capacity of 95% or more, and that a beam correctly pointed can bounce inside 6 to 9 times, before re-bounce to the exit .....

As example, considering a 10W beam that bounce also just 4 times, loosing 95% of its energy in each bounce ..... 10-95%=0.5 > 0.5-95%=0.025 > 0.025-95%=0.00125 > 0.00125-95%=0.0000625 ..... when it come out again, it's a halo of 6.25 microwatt (a halo, not a beam, cause the inside surfaces are matte, not speculars) ..... safe enough, imho

I didn't think about sand blasting. I thought it was a different kind of coating inside. Maybe I'll go touch it

Peace,
dave

 

[HIMNL9]

I didn't think about sand blasting. I thought it was a different kind of coating inside. Maybe I'll go touch it

Peace,
dave

It can also be, depend from the manufacturers ..... i had one times ago that was made in that way (sandblasted and anodized opaque black), but surely it's not the only way for make a low reflective surface

That what left me perplexed, instead, is the flat aluminium colored ring around the aperture of the one linked ..... not the better thing to place around an aperture where you are supposed to shine a high powered laser beam, just in case that the beam gets misaligned and hit it, imho ..... :thinking:

 

[Trevor]

I didn't think about sand blasting. I thought it was a different kind of coating inside. Maybe I'll go touch it

Peace,
dave

Since I've had no bites on this, how's the coating in yours? Durable? Had any problems with it so far?

I was also considering this one...

-Trevor

 

[daguin]

Since I've had no bites on this, how's the coating in yours? Durable? Had any problems with it so far?

I was also considering this one...

-Trevor

I never got around to actually touching it. I'm pretty good about not touching where my fingers don't belong so it slipped my mind A leftover from my days in construction, I think. I'll try to remember to touch it when I get home later today. Mine has been hit with 600mW of green, 1W of violet, and 800mw of IR without any problems.

Peace,
dave

 

[Trevor]

I never got around to actually touching it. I'm pretty good about not touching where my fingers don't belong so it slipped my mind A leftover from my days in construction, I think. I'll try to remember to touch it when I get home later today. Mine has been hit with 600mW of green, 1W of violet, and 800mw of IR without any problems.

Peace,
dave

Erm, if I were you I probably wouldn't. On the site the coating looks 'dusty,' that's more what I'm interested in. I'm very seriously considering springing for the Melles-Griot one...

-Trevor

 

[Laser_Ben]

Best way to make a cheap beam dump is to use a stack of 30-40 razor blades. If you stack them flat against each other, the angle on the cutting edges will infinitely reflect the beam back inside. I have made several like this and they work well. There is also no coating to damage, so the only failure mode is melting.

 

[lasersbee]

Hmmmm... gonna need to try that...
The only problem I can see is inadvertently cutting yourself..
Maybe install them in a shroud..

Jerry

 

[Laser_Ben]

Hmmmm... gonna need to try that...
The only problem I can see is inadvertently cutting yourself..
Maybe install them in a shroud..

Jerry

It is actually hard to cut yourself with it when it is all done. You can rub your finger along the edges and it doesn't cut because the pressure is distributed across many blades. I wouldn't recommend trying to do that though.