Dating as far back as the early 1960’s, researchers were zapping tattoo inks with laser light was an effective way to remove the markings from human skin. At the time it was prohibitively expensive. But the desire to have an undo-button for badge choices is strong, and thus the tattoo removal gun was born.
These days you can pick up one of these zappy, burn-y wonders for far less than a flagship cellphone put their high-power-output to alternative use. [Andrew] recently discovered that these devices can be readily repurposed into a laser welding tool with just a bit of work under the hood.
He first came across the technology via videos from [styropyro], whose work we’ve featured before. The tattoo removal gun features a YAG laser, which is pulsed to create a high power density. In initial testing, the pulses were too short and of too high intensity to effectively weld with; instead, the pulses simply cratered the metal.
After delving in further, [Andrew] discovered that by removing the Q-switch optical component, the pulses from the laser could be lengthened. This reduces the power density, and allows the tool to weld various materials even on its lower power settings. Success was found welding steel, titanium, and other materials, though attempts to weld copper and silver faced little success. Test pieces included razor blades and small screws, which could easily be welded with the tool. Results of the razor blade welding is spectacular, with a high-quality welding bead achieved by taping the laser to a CNC mill for precise movement.
It could prove to be a useful tool for those experimenting with complex projects involving bonding metals at very fine scales. If you’re pursuing something exotic yourself, we want to hear about it!
This is soooooo dangerous it’s unbelievable. You need the correct laser safe glasses that can protect your eyes and then the correct protective gloves and clothing as the laser energy from direct exposure and reflections can cause serious burns!!!!
DO NOT TRY THIS AT HOME!!!!!!!
But I live in a high energy laser research lab, if I can’t try this at home, where should I try it?
Dude, chill.
A pair of suitable laser goggles that can be trusted is a must. But beyond that, the laser is only dangerous to other unprotected eyes (be very mindful of windows and open doors…)
The burns are very small and localized + they instantly hurt, so there’s natural negative feedback to keep yourself out of the firing line, unlike with, say, a powerful X-ray source, where the damage becomes apparent only after some time and you feel absolutely nothing when roasting yourself with it.
Less dangerous than a welder tbh. Get the right glasses and you’re good.
Honestly, why do you have to look directly? $20 USB web cam and put the zappy parts in a light tight box.
You will need a filter for the canera though as the laser, even reflected, will destroy the camera sensor
Camera sensors are much cheaper and easier to source than new eyes.
Just put a cheap laser goggle glass in front of the webcam. The damage threshold for a cmos sensor is quite high anyway. And a webcam is cheap to replace
“Chill” is never an appropriate response to safety issues.
Never.
Not ever.
I agree most people should not go near this. Those who are willing to research and take proper precautions still take on risk of an accident.
Well, some people should not be allow to drink water from a glass as well.
They might drown.
Chill!! … please!
Bruce perens…. Yes agreed! Of course you’ re aware that it’s hard enough to ” mitigate”(lol) groups of people and injuries that may arise. Hopefully your precaution is headed. Eyes are simply irreplaceable!!!!!
It is a tattoo removal laser and it is at a lower setting than for tattoos so other than your eyes it is completely safe.
All you need is a good, imposing, shiny, reflective yellow vest as protection.
Didn’t Santa bring you one?
> researchers were zapping tattoo inks with laser light was an effective way
You might want to rephrase, also, have multiple pairs of eyes on your articles.
Some spare eyes is indeed a good idea when messing around with lasers!
God in her infinite wisdom, supplied me with another..
Yes, God is all about redundancy.
All about symmetry, actually.
It’s amazing to me that you’d take so much time, on Christmas no less, to comment on the erroneous addition of a single character. God your life must be dull.
Copper ist used on reflector mirrors in YAG Lazors (the ones i worked with), so i guess you cannot use this wavelength to weld it.
when lasers are used for removal of any kind it is classified as a medical device and controled by the cdc.
heck the cdc even controls laser cutters featured on the board before.
so i dont thinkyou can avoid medical classification by repurposing
https://en.wikipedia.org/wiki/Laser and https://en.wikipedia.org/wiki/Laser_safety are 2 good places to read before getting involved in lasers as it is easily possible to burn your eyes even on lower power lasers.
As a medical device engineer, I’m fairly confident that you mean FDA, not CDC.
It’s easy to buy medical devices and supplies, even unexpired ones. Many devices may be labeled as “Rx only”, but they are not regulated like prescription medication and can easily be purchased by resellers. Check out esutures.com
Also, FDA doesn’t really regulate off label use, even ones that are contraindicated. Just so long as the company selling the devices or the manufacturer doesn’t market the devices to be used in any way that they didn’t disclose in their submission.
I can see a use for this doing SLS 3d printing metal at home… might have to get one to start experimenting with.
Get ready to buy a lot of argon.
you will not do any meaningful SLS with this…the flashlamp has a finite number of pulses it will take until it goes boom.
Does anyone have a source for the laser used? Will the $500 one shipping from the US on ebay work? link: https://www.ebay.com/itm/2000MJ-Laser-Tattoo-Removal-Q-Switch-ND-Yag-Laser-1064nm-532nm-Black-Doll/273856691549
Keep in mind that in US there might be problems with importing a class IV laser.
Also, invest in proper 1064nm (and/or 532nm if you plan on using the doubler crystal) goggles, the ones provided with the machine will jack shit against this kind of power…you have only 2 eyes and they’re worth way more then what a good pair of laser goggles cost.
And this one will probably work, they all seem to have the same guts.
What experience did you have importing class IV lasers? I’ve never had a difficulty with that, but then, I’ve always imported lasers in some kind of industrial product (CO2 laser cutter) or as an OEM module that was obviously not a consumer or medical product (multiwatt diode lasers.)
Those are not class IV lasers. But when importing anything, the sender usually doesn’t give proper information on the customs forms anyway.
I was given one of these about six months ago. It sits in my man cave, me being too scared to even plug it in.
I have to admit to wondering if it could be useful for something other than the intended use but not wondering enough to ever plug it in.
If you wish to sell it, i am interested…
I accidentally came across one of these a week or so ago, and I’ve been patiently waiting for a teardown video to see if there’s any chance to do something interesting with these: https://www.ebay.com/itm/Portable-Picosecond-Laser-Tattoo-Removal-Pen-For-Mole-Dark-Spot-Acne-Freckle-USB/264445324447
At $50, the price is right.
From the descriptions I think they use a blu ray laser diode. I’m also very curious about what it is capable of since with the short pulse it might still do something interesting.
A reminder… familiarity breeds contempt (of common sense safety), and the consequences are irreversible
https://www.photonics.com/Articles/Laser_Safety_Little_Mistakes_with_Big/a25167
“Yet an examination of the record of laser accidents reveals that, in virtually every case, the injury results from a carelessly taken shortcut, a shortcut taken by someone who should know better but in the interest of expediency, takes an unnecessary and ultimately very costly risk.”
Came here to thank you sharing this amazing article. This must be read by everyone which wants to do some work with lasers. There a plans to work and do some DIY with Nd:YAG lasers and already bought a laser safety goggles with high OD for infrared, but this is worthy to put that first in list when doing stuff with lasers.
Can this be used to etch/ablate copper on a pcb blank? If so it’s time to start a low cost direct etch pcb prototyping tool.
The second harmonic (532nm) is better for copper, but this is the starting point, and the SHG crystals / optics are commercially available.
if you leave the passive Q-switch in and use the doubler crystal, it will blast the copper off. But – this uses a flashlamp as the pump source, they don’t last forever, especially with repetitive use. CNC-anything will quickly go through flashlamps.
I see. Thanks for the response.
The laser is more better to drill micro vias in PCB’s then etching a circuitry.
If you’re worried about safety, I’m sure that something like this would be 𝘱𝘦𝘳𝘧𝘦𝘤𝘵𝘭𝘺 safe.
https://www.ebay.com/itm/NEATCELL-Picosecond-Picosured-Laser-Beauty-Machine-Tattoo-Removal-Pigment-Pen/392569948521
and is this really a picosecond laser or just a blue laser diode in a different enclosure?
Because if it truly IS a picosecond laser, it would not be much safer. If it can blast off tattoos, it can blast off your retinas…
I own one of these (bought just out of curiosity) and measured the actual optical pulse width of mine at 1.2ns using a 12GHz photo-diode on a 10GHz scope. These things use a gain switched laser diode, and they only last around 20,000 laser shots before the laser diode burns out.
I would very much like to know more. Would you be willing to put up pictures of the internals and/or describe your findings/experiments with these?
I’m going to weld my eyebrow ring to my nose ring
It’s interesting they have two different colors. I remember MANY years ago where semiconductor lasers were all pulsed, but didn’t think they still made them. Are these regular laser diodes pulsed way over their rating for a very short pulse? Laser diodes driving a Yag with a Q Switch? Something else?
Plus when the camera bakes it’ll provide a pretty good clue that there’s way to much reflected light to be safe. And you can then design it to be better!
Although if it’s on a CNC gantry I’m not sure why you’d ever want to leave it blasting dangerous light around instead of inside a safe enclosure.
Perhaps the author has some retinal damage for some reason…
(I’m aware the HAD author and the project source are not the same person.)
Less perilous than a welder tbh. Get the correct glasses and you’re acceptable.