Laser welding of undrilled cells.

Hedges

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"Operator protective equipment including welding gloves, welding shield and 1070 nm laser-safe glasses are required"

Does not specify what (log scale) attenuation the glasses must provide.

"Danger
Invisible laser radiation
class 4 laser product

class 4 invisible laser radiation
when open
avoid eye or skin exposure to
direct or scattered radiation"

"Max average output power 2500W
Peak peak output power 5000W
Pulse duration >= 50 us
pulse repetition rate 0 - 10 kHz
Wavelength range 900 - 1200 nm"

"Part contact electrical interlock turns off the laser power if the welding head is not in contact with the welded parts"

Ah, that's the trick. Laser is supposed to be contained by tip contacting workpiece?
Several tips available, some look quite open. Reflected light from molten surface seems likely.

"Class 2M laser product
Max. Average Power 1 mW
Wavelength range 600 - 700 nm"

1mW? That's a laser pointer.

class 2M? Eye protection is provide by the blink reflex.

That is apparently a visible laser pointer so you can see where the welding laser will be applied.

Compare to:


"Like electron beam welding (EBW), laser beam welding has high power density (on the order of 1MW/cm2) resulting in small heat affected zones and high heating and cooling rates. The spot size of the laser can vary between 0.2 mm and 13mm, though only smaller sizes are used for welding."

What a difference capitalization makes!


"A Class 2M laser is safe because of the blink reflex if not viewed through optical instruments. As with class 1M, this applies to laser beams with a large diameter or large divergence, for which the amount of light passing through the pupil cannot exceed the limits for class 2."
 

Terrapin

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"Operator protective equipment including welding gloves, welding shield and 1070 nm laser-safe glasses are required"

Does not specify what (log scale) attenuation the glasses must provide.

"Danger
Invisible laser radiation
class 4 laser product

class 4 invisible laser radiation
when open
avoid eye or skin exposure to
direct or scattered radiation"

"Max average output power 2500W
Peak peak output power 5000W
Pulse duration >= 50 us
pulse repetition rate 0 - 10 kHz
Wavelength range 900 - 1200 nm"

"Part contact electrical interlock turns off the laser power if the welding head is not in contact with the welded parts"

Ah, that's the trick. Laser is supposed to be contained by tip contacting workpiece?
Several tips available, some look quite open. Reflected light from molten surface seems likely.

"Class 2M laser product
Max. Average Power 1 mW
Wavelength range 600 - 700 nm"

1mW? That's a laser pointer.

class 2M? Eye protection is provide by the blink reflex.

That is apparently a visible laser pointer so you can see where the welding laser will be applied.

Compare to:


"Like electron beam welding (EBW), laser beam welding has high power density (on the order of 1MW/cm2) resulting in small heat affected zones and high heating and cooling rates. The spot size of the laser can vary between 0.2 mm and 13mm, though only smaller sizes are used for welding."

What a difference capitalization makes!


"A Class 2M laser is safe because of the blink reflex if not viewed through optical instruments. As with class 1M, this applies to laser beams with a large diameter or large divergence, for which the amount of light passing through the pupil cannot exceed the limits for class 2."
All great info to keep in mind movin fwrd.
 

Hedges

I See Electromagnetic Fields!
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I would play it safe and use a welding helmet.

That wouldn't do a damn bit of good.
Welding helmet has a lens to block UV, which comes from electric arc. (gas welding goggles only block bright light)

For laser welding, need something like this:


"1064nm - OD 7+"

What that means is 10^7 attenuation of light in the 1064 nm range, which is about what that welder needs.
It puts out 5000W peak pulse, and eye damage can occur with more than 1 mW. Because IR, you don't see it.
5000/10^7 = 0.0005
The laser pulse could have specular reflection off molten metal, and a momentary flash could damage your eyes. It has happened (reflect off a jewelry, etc) with much lower power lasers.
Some eyewear is thin-film, so attenuation is a function of incident angle. Also subject to being scratched.
 

Luthj

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A laser that powerful would typically be bolted to a table in a room with several locks on the door. Then you would need 500$ glasses and 2 weeks of training to use it. Even the reflection from a laser that powerful can cause permanent blindness in a fraction of a second. At least in a commercial setting in the USA. I am not sure what a north american seller would require to sell that to a member of the general public.
 
Last edited:

Hedges

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I've had training (mostly safety) but little hands-on.
If possible, set it up with a camera for remote viewing, so only hardware is at risk, not your eyes.

I would say do it in a glove box to block light, but the laser welders have enough power to burn skin and start fires.

For the specific application of battery terminals, you could set up a jig with table or turntable that allows the desired motion.
Interior an absorbing color. Convoluted paths at interfaces to block light from escaping, with interlock on lid.
Then you've done engineered controls to operate as class 1 product with class 4 laser inside.
 

Hedges

I See Electromagnetic Fields!
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Messages
9,308
I looked it up and my auto darkening helmet is not acceptable for laser. Bummer.

Besides sufficient attenuation of particular wavelength, two other problems:

Ones is the (LCD?) wouldn't be fast enough; damage is done before it closes.

Second is those work by means of a sensor, located several inches from line of site. Intended for flood illumination, not a 1mm diameter beam.
People say they weld under their car and it fails to darken, because sensor was blocked.
 

DerpsyDoodler

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A laser that powerful would typically be bolted to a table in a room with several locks on the door. Then you would need 500$ glasses and 2 weeks of training to use it. Even the reflection from a laser that powerful can cause permanent blindness in a fraction of a second. At least in a commercial setting in the USA. I am not sure what a north american seller would require to sell that to a member of the general public.
My guess would be a lot of money. I’m certain there’s a reason no price is listed.
 

Quantes

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It takes a lot of time to learn how to do quality welding. Moreover, it is necessary to constantly combine practice and theory. These two elements will allow you to learn how to weld as quickly as possible. If you can enroll in a course, that would be fine. You should also know information about each material. I'm not really an expert in welding. My main occupation is making knives. Recently I found a helpful site for me https://www.cherokeeobserver.org/best-steel-for-knives/, which tells about the best knife steels. You can find information about welding there as well.
 

schmism

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Location
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Just came across this and thought it may be helpful. The tech is getting smaller and available...
to be clear, if its not CNC controlled its no different than hand welding them with a TIG. (the point being the time, durration, distance, etc is all closely controled by the setup as to limit/prevent damage to the cells)
 
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