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Registered Member #4762
Joined: Sun May 06 2012, 05:59PM
Location: Russia
Posts: 93
A rather simple way to get much more fun out of cheap Chinese CO2 laser is making it portable. I was too lazy (and lacking some necessary skills) to make this project smooth, but this thing still didn't fell apart after several weeks and proved itself quite useful to light up a fireplace in my house The laser resonator is enclosed in acrylic tube and fixed with polycarbonate circles. Water cooling is done with small 5w 12v pump and a water tank with no fans or radiators, so long runs are not recommended (however they won't be possible due to small battery capacitance). High voltage comes from a pushpull, custom AC flyback transformer and a voltage doubler, which are powered by an RC Li-ion battery (11.1V 3700mah), which provides ~5 minutes runtime which is more than enough to have fun. Drain current from the battery is ~20A. Perhaps the pushpull can be replaced with any proper ZVS module from ebay/aliexpress, which could make this even more simple. The handle is just a simple slingshot with power-on button attached.
Aiming is a bit tricky, but I'm planning to add a red dot laser scope to make it easier.
Effective range of lighting fire from dry wood is about 2-3 meters (within time range of 0.5-2 seconds). Adding a ZnSe lens to the output decreases the range to 50 mm, but focus becomes a hot spot, melting all the hard stuff (ceramics, stones, glass, quartz, even thin steel, like shaving blades or paper knife edge) and cutting organics just like a proper CO2 CNC.
The last photo shows some interesting effect: its freon (R22) flowing from the hose into laser beam and burning in the focal point. Freons show uncommon property for gases: they absorb far infrared, so it ignites easily. Don't inhale the products, they are really not tasty.
I am trying to make a nice video about this laser gun, but, again, I'm too lazy and lacking skills for that, so only photos for the time being.
DO NOT TRY TO MAKE SOMETHING LIKE THIS BY YOURSELF. HERE ARE LASERS INVOLVED, LASERS ARE DANGEROUS. DO NOT LOOK INTO THE BEAM WITH REMAINING EYE. LIVING IS DANGEROUS TOO, PEOPLE SOMETIMES BECOME DEAD IN THE END OF THEIR LIFE. BETTER RUN AWAY SCREAMING NOW.
Registered Member #4762
Joined: Sun May 06 2012, 05:59PM
Location: Russia
Posts: 93
40W sounds much, but this is not visible light. The only real damage it can apply is overheating your eyeball if you've managed to stabilise it in the beam somehow (which will be homemade laser optical surgery, by the way). Moreover, it is being reflected only by metal objects. It seems to me that there is very little chance a beam pointed at the wooden wall would find a metal object there and reflect just into my eye.
However, I find your notice important enough in general way, so I thank you for paying attention to safety rules, but mine and colleagues experience is sufficient to understand what we do and to have conscious understanding of things we work with, so you can relax, no one was hurt, no one would be, and if he is, your warning and/or worrying after me won't have any effect on preventing this from happening in any way.
Registered Member #3324
Joined: Sun Oct 17 2010, 06:57PM
Location:
Posts: 1276
zrg wrote ...
40W sounds much, but this is not visible light. The only real damage it can apply is overheating your eyeball if you've managed to stabilise it in the beam somehow (which will be homemade laser optical surgery, by the way). Moreover, it is being reflected only by metal objects. It seems to me that there is very little chance a beam pointed at the wooden wall would find a metal object there and reflect just into my eye.
However, I find your notice important enough in general way, so I thank you for paying attention to safety rules, but mine and colleagues experience is sufficient to understand what we do and to have conscious understanding of things we work with, so you can relax, no one was hurt, no one would be, and if he is, your warning and/or worrying after me won't have any effect on preventing this from happening in any way.
Yes, but is it worth leaving any chance on such a thing?
Please, read that fully. I did and it quickly got me to sell off the 70W DDPS laser brick I had brought without testing it.
Registered Member #3215
Joined: Sun Sept 19 2010, 08:42PM
Location:
Posts: 780
I have some knowledge and operation time also, but it didn't protect me from scatter and I have some spots on my retina and/or top layers of the crystalline
IR light at power levels higher than 500mW can burn patches when direct reflection or scatter occurs... at power levels of more than 1-5W scatter from combustion can also occur since some fumes and some combustion byproducts can also shine back a significant amount of light
the wavelengths over 1500nm are for sure not easily reaching your retina, but can and will produce patches on your crystalline if the power is high enough
also pay attention that chinese CO2 lasers are not always only producing the 10.600nm wavelength and that there are other lower range emission peaks for CO2
that's never a bad idea to use protective goggles, and CO2 goggles are cheap as the wavelength is easily blocked by crude glass
I had OD5 and OD7+ goggles for green + IR and still have had a burn or two, so please consider safety
Registered Member #135
Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735
zrg, you can do whatever you want, but realize that this is a community and when we post something that someone else is going to duplicate, THEY can hurt themselves because of a lack of experience.
Recently a young boy was killed making a Jachob's ladder out of a MOT. The forum is not responsible for this, but as a source of information it is used by all as a guide, and without respect for the things we play with, people have been and do get hurt or killed.
FWIW, I have burnt lots of magnesium, made carbon arc lights, played with stick welding, and regularly use a torch, but you know, you only get one set of eyes and one accident happens very quickly and I need my eyes for my job. I am 37 now and more cautious and AWARE of what I am doing and what impact it might have.
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
Awesomly cool ! but it shouldnt be difficult to find the spectrum of emission and find a material to attenuate it to protect your vision. There might be side colors in the IR and UV side your not aware of.
Registered Member #4762
Joined: Sun May 06 2012, 05:59PM
Location: Russia
Posts: 93
Hazmatt, thank you very much for your responsibility. This is a great example of making this world a better place to live. I added a warning in the end of original post to prevent any unfortunate events that may be caused by some young boys going to duplicate something dangerous described here.
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40W CO2 laser gun
