Tattoo removal laser for cutting?

Hi everyone,

I'm thinking of making a laser machine that would allow me to cut through various materials, such as metal and ceramics.
There are fiber lasers available that are designed specifically for cutting, they are Q-switched and have pulse frequencies in 100-400 kHz range. The problem is that with my budget I can buy up to 50W laser which is not able to cut through more than 1-2mm of material and I need to cut 6 mm or more.

I noticed that tattoo removal lasers are quite cheap, they are also Q-switched and their pulse energy is hundreds times higher compared the dedicated lasers I mentioned above, so presumably they could penetrate through much thicker objects. However the pulse frequency of tattoo lasers is just 10 Hz or lower, which would obviously make the cutting speed less.

Considering that I don't need high cutting speed, do you think it would be possible to use tattoo removal laser for cutting through thick materials by focusing it's beam into a very small spot? I.e. 10-20 microns?

Thanks

A spot that small would only be possible with a single mode laser, and only for the focal POINT. It will quickly diverge either side, so the bottom of the material will be 6mm+ "out of focus". They're just a few watts of average power. Qswitch or not, that's not enough power to cut quarter inch steel.

Get a band saw. They're cheaper, safer, more robust, lower energy bill, less complex, more reliable, and MUCH faster than the method you propose.

Thanks for your answer. Saw is what we use now, but there is a dire need to cut with smaller kerf, and cut complex shapes, thus I'm looking at laser option.

50W fiber Q-switch laser cuts up to 2mm thickness just fine, so I guess a 500W fiber could go though 6mm, but those are too expensive, besides I don't need such high cutting speed that they provide.

For focal point - I guess the same consideration applies to 2mm thickness too, i.e. we never have ideally focused point, and nevertheless it still works provided the power is sufficient to cut though. Maybe if I have longer focal distance lens that would help?

Also you mentioned "single mode" laser, do you have any info on tattoo lasers if those are single mode or not? Thanks

What's stopping you from using a grinder, or a plasma cutter if you have that kinda cash? Or for cutting out "complex shapes" you can use a bandsaw as Cyp mentioned perferably for softer metals.

I'm not sure how "complex" you're talking but a laser cutter just isn't the best tool for the job, you might even want to consider a cnc mill.

3dlev said:

do you have any info on tattoo lasers if those are single mode or not?

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You're missing the point. They don't have enough power. Google says 1-2J at 1-6Hz which is 12W average at most. If 50W is required for 2mm, 12W is not sufficient for 6mm material. Either find the cash, or use a different method.

Cyparagon gives very good advice. Searching on this myself I can sure find a lot of 500W lasers available to cut through 6mm of mild steel being advertised online. No way a tattoo machine can do anything for you for such a use, their duty cycle is very limited & can't produce that kind of average power, or the required repetition rate.

IMO, another good option for what you're looking to do is an 'abrasive water jet' machine, it will do what you're asking for and much more.

Here is an excerpt from the Wikipedia article on water jet machining:

"Water jets are capable of attaining accuracy down to 0.005 inches (0.13 mm) and repeatability down to 0.001 inches (0.025 mm).[35]
Due to its relatively narrow kerf, water jet cutting can reduce the amount of scrap material produced, by allowing uncut parts to be nested more closely together than traditional cutting methods. "

I would check into these, they come in any size, from a couple of square feet to hundreds of square feet, to suit your particular needs. :yh:

Edit: Here's a photo of an example of what can be done on a water jet cutter; you can literally cut most anything, from meat to marble!

Thanks Alaskan, BowtieGuy

Waterjet unfortunately won't work, as one of the tasks that I have is cutting Silicon carbide which is extremely hard to process with waterjets. Besides waterjet kerf width is same size as the saw, and we need smaller size.

What our competitors are using is water jet-guided laser - these normally have green 532nm Q-switch lasers of just 15W power and are able to cut through 6mm silicon carbide just fine. But those cost a fortune.

My initial thought was - if tattoo laser has so high single pulse energy - can it punch through the whole material thickness in a single shot? Provided it's focused to 20-30 microns.
Again, I don't care about cutting speed, thus it's not the average power I'm looking into, but the pulse energy. Thanks

3dlev said:

if tattoo laser has so high single pulse energy - can it punch through the whole material thickness in a single shot?

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1.5 joules is required to punch through a razor blade. That's about 0.009 inches, or 0.2mm. As the hole deepens, the energy hits the sides more and more, instead of the bottom of the hole, spreading out the power drastically.

Why would you ask for advice and then ignore the advice you're given by everyone? Let me put this as plainly as I can:

IT WON'T WORK.

Cyparagon,

Thank you very much for the numbers - that's what I was looking for when I made the original post. Can you recommend any literature to read to get similar figures for other materials?

I certainly don't ignore the other advice, it's just the saws, waterjets etc don't work for me as I explained, and while I certainly appreciate hints in other directions, I came to laser forum to seek information specifically for lasers. Hope this makes sense.

3dlev said:

Cyparagon,

Thank you very much for the numbers - that's what I was looking for when I made the original post. Can you recommend any literature to read to get similar figures for other materials?

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Google is your friend....

Jerry

3dlev said:

Cyparagon,

Thank you very much for the numbers - that's what I was looking for when I made the original post. Can you recommend any literature to read to get similar figures for other materials?

I certainly don't ignore the other advice, it's just the saws, waterjets etc don't work for me as I explained, and while I certainly appreciate hints in other directions, I came to laser forum to seek information specifically for lasers. Hope this makes sense.

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It seems sometimes getting the information that you want over the information someone thinks you should be looking at instead is kind of like pulling teeth am afraid, To get what your really after requires a very carefully and delicately crafted question, One wrong word and your doomed to get a bit of the old runaround. :banghead:

Been there, done that. It's the newbies trip point, if you don't word your question correctly, you won't get what you want. Problem is, if you are completely new to the subject, you do not know enough to be able to ask the right questions. Google is no different, but hammering away with wrong question after wrong question, in time, if you read through what it will give you, eventually you learn enough to start asking the correct questions.

Alaskan said:

Been there, done that. It's the newbies trip point, if you don't word your question correctly, you won't get what you want. Problem is, if you are completely new to the subject, you do not know enough to be able to ask the right questions. Google is no different, but hammering away with wrong question after wrong question, in time, if you read through what it will give you, eventually you learn enough to start asking the correct questions.

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Correct ! But at any time along the way and one wrong word latter and it won't matter how many correctly worded questions you ask after that because your quest could be derailed for who knows how long, It depends a lot on the people on BOTH sides to get the quest back on track..... :knight: