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cnc laser engraver for logos and whatnot, what should I get?

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  • cnc laser engraver for logos and whatnot, what should I get?

    Looking to put logos on aluminum and probably other materials down the road. I don't need to cut anything with the laser or anything to fancy.

    I see there is fiber and co2, what is the difference between these two? Does the co2 laser need an actual bottle of co2 (like a welder) to operate? I read the fiber one can't do wood so I think I will avoid that style.

    There are lots of cheap options on ebay. Are these to be avoided or some of them good?

    Like this one: http://www.ebay.com/itm/High-Precise...UAAOSwFdtX146J

    It says it will engrave everything "nonmetal" but some mention it will mark metal?
    Andy

  • #2
    no... CO2 laser does not need a bottle Totally self contained - the gas is inside.

    BTW. CO2 an IR laser so (like all lasers) take care with you eyesight at all times. Even the 532nm (green) units we use are work won't even fire if either of two door interlocks are not in place.


    Laser marking of Aluminum is usually done by ablating an anodized surface. Are you wanting to "mark" or "carve"?

    "Fiber laser" are usually YAG (also "invisible") - Entirely different application set to a CO2 laser. Capable of a very small focused dot so intensity for same power is much greater than say CO2.
    Last edited by lakeside53; 09-04-2017, 02:06 PM.

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    • #3
      I looked into it a little; Here are a few things that surprised me, despite being logical.

      1) Lasers don't deal with curved surfaces very well. If you are doing cylinders you will need a mechanism to rotate it.

      2) IR is dangerous, and you don't have a built in mechanism to avoid eye damage from IR like you do with visible light. Eye protection is needed at all times.

      3) The color of the part you are marking sometimes makes a difference in how effective the laser is.

      4) Engraving is preferred over laser for some applications.
      At the end of the project, there is a profound difference between spare parts and extra parts.

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      • #4
        If I recall correctly, there was some discussion of laser engraving/cutting in the 3D Printing Superthread.

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        • #5
          A couple of things. People think of lasers as a narrow beam. They are much larger and get focused to a very small spot. This is why they don't work well on curved surfaces, they become unfocused.

          YAG lasers are used with fiber optics because the wavelength works well with fiber.

          The hot lasers today are fiber lasers, where the fiber is creating the laser light, not just transmitting it. They are 80% efficient rather than about 20% like other high power lasers. That's a game changer and they are already available at 100 Kw power levels and can butt weld 4" thick steel from one side in one pass!

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          • #6
            Originally posted by Max McGrumpy
            Lets hop to it now, here's the perfect chance to troll the f*ck out of another thread and let everyone see your true colors.
            Well, now that it has already been done...
            Location: North Central Texas

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            • #7
              I have a Vevor 50W CO2 laser with a 300mm x 500mm bed. The laser includes a rotary unit for engraving round objects. Checkout the forum at https://rdworkslab.com/

              You basically have two choices: buy a very expensive American laser, ready to run; or buy a relatively inexpensive Chinese unit, but be prepared to learn its quirks and spend some time shaking out and setting up the machine.

              And I'll go ahead and start the firestorm: don't worry about your eyesight and interlocks aren't even included on many machines. This is because the power of a CO2 laser falls off extremely rapidly outside the focus zone.

              Feel free to PM me if you have questions.
              Kevin

              More tools than sense.

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              • #8
                Small CO2 lasers like what most hobbyists have will only mark organic materials like wood and plastic. They can vaporize the dye out of anodized aluminum. It not until you get into the couple hundred watt range with a CO2 that you can start actually marking metal.

                Fiber lasers are q-switched so they have high peak power which can mark metals. You can also get non-fiber DPSS marking units, they are a bit cheaper.

                CO2 eye safety is easy, just about anything will stop CO2. Fiber lasers and dpss are generally around 1064nm and is much more difficult to stop. These systems also usually use galvos to scan the beam on the surface which mark really fast.

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                • #9
                  So much stuff I don't understand haha. Thanks so much for the feedback everyone so far!

                  I am curious why can't (or can they?) a fiber laser mark nonmetal materials?

                  Initially I thought for sure a 40w laser would be enough to mark metal.

                  The metal I would like to mark is just bare aluminum. Not looking to do thousands of parts so getting it done super fast isn't a necessity. Probably 10 parts a week or so.

                  Is there any coating that can be wiped or sprayed on the aluminum to aid the marking somehow? Not anodizing but more like a fluid that can be applied, lasered, then wiped off.
                  Andy

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                  • #10
                    I've seen experiments with moly film to mark metals with a laser. Seems to work mush like a laser printer. Here's a writeup: http://www.evilmadscientist.com/2013/laser-moly

                    Of course, you could always try saving the laser engraver, and use a laser printer instead: http://www.daftmike.com/2016/02/expe...-transfer.html

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                    • #11
                      Sir John posted some information about LASER marking:
                      http://bbs.homeshopmachinist.net/thr...rking-on-Tools
                      Location: Long Island, N.Y.

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                      • #12
                        Originally posted by achtanelion View Post
                        I've seen experiments with moly film to mark metals with a laser. Seems to work mush like a laser printer. Here's a writeup: http://www.evilmadscientist.com/2013/laser-moly

                        Of course, you could always try saving the laser engraver, and use a laser printer instead: http://www.daftmike.com/2016/02/expe...-transfer.html
                        Originally posted by RichR View Post
                        Sir John posted some information about LASER marking:
                        http://bbs.homeshopmachinist.net/thr...rking-on-Tools


                        Great reads!

                        Now I am curious again, why $1000 difference between the 40w machine and 50w machine? I can see the 50w machine is bigger over all and I am sure some better motors/servos but $1000?
                        Andy

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                        • #13
                          Originally posted by vpt View Post
                          Is there any coating that can be wiped or sprayed on the aluminum to aid the marking somehow? Not anodizing but more like a fluid that can be applied, lasered, then wiped off.
                          Several including LaserBond 100 http://www.laserbondingtech.com/ EnduraMark https://enduramark.com/ CerMark https://cermarksales.com/ and Molybdenum Disulphide spray see https://www.youtube.com/watch?v=b_06laAjMPc

                          Now I am curious again, why $1000 difference between the 40w machine and 50w machine? I can see the 50w machine is bigger over all and I am sure some better motors/servos but $1000?
                          Absolutely worth the price difference. Many factors are involved and the difference between a 40w and 50w tube is just one factor. More importantly is the precision (step length) available in the larger machines.
                          Kevin

                          More tools than sense.

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                          • #14
                            The cheap desktop co2 lasers are kinda crap. Very basic x-y gantry. Older ones connect via parallel port, newer ones have a very basic USB interface. Software is kind of crap too.

                            When you get up to the next level machines they have their own dedicated laser controller. You can buy these controller from lightobject and the new ones are pretty nice, color screen to preview what you are going to cut and you dont need a dongle anymore to run the programming software. I think they sell for about $400 by themselves. Newer controls also do PPI (pulse per inch) which pulses the laser as it travels for more consistent power control.

                            The sprays do work but are kind of expensive and in the long term if you are going to need to mark metals you are going to want a fiber laser or dpss system. Or find a local company that can mark stuff for you.

                            Fiberlaser will mark organics too, its just there are many plastics that appear to be opaque and are actually transparent at infrared wavelengths. I have tried shorter wavelengths (355nm UV) cutting plastic and it does not work worth a damn even though they would cut thin metals. It did work for polyamide though which absorbs nicely in the UV range. Tried polyamide at 1064nm (dpss or fiber) and I had to crank the power up big time because it is almost transparent at that wavelength. 532 was not much better.

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                            • #15
                              Sooooo.

                              What kind of lasers can be had for "best bang for buck"? I came across some videos and am now possibly interested in making a mounting bracket for a laser head on my plasma table.
                              Andy

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