Reflection from laser

[John Henriksen]

Check plastic (acrylic) suppliers in Europe particularly you own area.  They should have ORAMGE  which appears to be the best for BLUE lasers.....Ensure the OD is =4 or above.

Thanks 

[ThothLoki]

Yes. Best bet is to get OD rated orange plastic. I got some random orange acrylic from a neighbor and do not know what the rating is but it seems to work well (yes, I did the idiotic thing of looking though it without glasses when the laser was on). I do not suggest you leave the window open all the time but have a flap that goes over it (cardboard with a duct tape hinge in my case)

[John Henriksen]

Yes. Best bet is to get OD rated orange plastic. I got some random orange acrylic from a neighbor and do not know what the rating is but it seems to work well (yes, I did the idiotic thing of looking though it without glasses when the laser was on). I do not suggest you leave the window open all the time but have a flap that goes over it (cardboard with a duct tape hinge in my case)

Hi

Do you know how to messure OD?

[Stonemull]

Without buying some expensive gear the best sensing stuff you have are your eyeballs.
I bought some cheap <$3 red safety glasses from china and wanted to ensure they wrre safe,
Easiest way was to set laser power at minimum and view the spot through the goggles, increased power until it was just visible, note the power. I then did the same with my Arc welding goggles (you can buy just the glass cheap too).
I know arc welding goggles are safe for UV .. so did make the assumption that the OD9 rating was fairly relevant to to the laser wavelength and that 100 on the laser power is twice as bright as 50.
 the red goggles are between a quarter and a half as good as arc welding glass from memory.
Which puts them in the OD8+ range since 9 is 10 times less light than 8, its a log function.
I am happy to stare at it burning full power with the red goggles on, throw the green ones away, they are terrible, little better than sunglasses, they are designed for red lasers.

[ROSS]

Buy at least a 1/4 inch thick (say 7mm ?)

Suggest you look here if you have not already.
.....Benbox Laser Machines/CO2 Lasers/3D Printers » General Category » Laser Safety » Acrylic Orange Shields

Many questions asked on this forum by newcomers can be answered IF people look through the SEARCH  and INDEX (front page).

[John Henriksen]

Thanks for all the good suggestions

I just came out with an idea

What about just shielding around the laser beam all the way down to the bed?

I would be able to 3D print box, but where is the pitfall?

here a quick drawing

[ThothLoki]

I have seen that. The only time there is reflection is when it hits the surface of the material you are burning.
The pitfall is when you are lasering odd shaped material.

I suggest to keep thinks inexpensive is to just go to a dollar store and pick up some foam board. I bought 4 pieces and left the back open. I have all of the corners and supports made on everything if that helps.

[John Henriksen]

Now I have build the box. I am not sure if it will protect anything with this acrylic if not I can all ways modify it with a darker film.

Tomorrow i will test it with the laser

[ThothLoki]

Remember. Test with you glasses on

[ROSS]

That's a pro looking job!...

(By the way...If the "floor" of the laser is solid then you really need a perforated floor...something like expanded aluminium..this allows debris from burning to fall thro and helps stop rear face of material being scorched too badly....+

[John Henriksen]

That's a pro looking job!...

(By the way...If the "floor" of the laser is solid then you really need a perforated floor...something like expanded aluminium..this allows debris from burning to fall thro and helps stop rear face of material being scorched too badly....+

Thanks 

Yes I need to find a solution for the bed and the floor, aluminium sound like a good solution, I all so need to make an exhaust system for the box and a carbon filter system.

[John Henriksen]

Remember. Test with you glasses on

Yes I will remember that  and set my girlfriend to watch without glasses  (just kidding)

Do you know a good way to test it?

[nottingham82]

a big ol sheet of aluminum or steal works great as an under the machine bed.   A honey comb over it works nice for cutting.

[ThothLoki]

Yes I will remember that  and set my girlfriend to watch without glasses  (just kidding)

Do you know a good way to test it?

Honestly, When I tested mine, I had my glasses on and peaked over the tops of them indirectly to see how intense it was. Probably not the best way, but I do not have all that expensive equipment to test it with

[nottingham82]

use a kid... they can regrow anything.