LaserUser.com Forum (formerly RDWorksLab)

I own/operate a sign/graphics shop in Minnesota. I have been doing this since 2001, working in a local sign shop before that. We offer pretty much anything printed: signs, banners, decal/labels, displays, etc. We also offer flatbed cutting/routing, items such as routed signs, die cutting, custom packaging, etc. Now our latest addition is an 100watt Aeon Nova14. I am very intrigued by technology and love to offer things that other do not. I love to learn about how each piece of technology works both to better understand and use, but also to be able to figure out the best way to do things and trouble shoot if needed.

I am hoping now to figure out all of the ins/outs of using a co2 laser. Things such as lens, alignment settings, engraving, etc.

Welcome Matt. We have quite a bit of info on those topics avaialble and links to a few other sites that we have found useful as well.
AND one of out moderators Gene Uselman - ran a sign shop for a good number of years AND lives in Minneapolis, Minnesota - maybe time for a road trip

Pete is too quick for me- here is mine...

Welcome Matt- your name is familiar, perhaps Signs 101? I am in Blaine and am still involved in my signshop- altho I am retired. Your machine looks very solid and is similar to mine. We find it very useful. Let me know if I can help in any way. Gene

I would also strongly recommend Lightburn software and I wish that it had come out when I was a rookie laser guy. It was developed by one of our members.

Thank you guys!! Yes, I am using Lightburn. I got both roller and chuck rotaries with mine, along with the lightburn camera.

Yes Gene, it is from Signs101. I thought your name sounded very familiar as well!

My main thing I am working to figure out now is focal lengths and power/speed settings. I am one that likes to know why the focal length needs to be set to 13mm for example. Then just figuring out power/speed settings for the vast array of materials for both cutting and engraving.

I don't know if anyone has turned you on to Russ's videos? We have a partial inventory of his youtube vids, he answers most of the initial questions that we all have. He is how most of the members find out about us, he rarely participates but does endorse the forum and we maintain communications behind the scenes. He is up to 175 vids now, getting more and technical, the early ones are a good place to start. https://www.youtube.com/user/SarbarMult ... jreload=10

Have you ever played with a magnifying glass to burn a hole in piece of paper or something else.....the focal distance is the equivalent of adjusting the magnifying glass to concentrate the sunlight to burn. With the laser you are adjusting the hieght to concentrate the infared energy developed by the laser to burn. Some times it is advantageous to de-focus the beam - all depends on the process you are executing.

The focal distance is a function of the type of lens and where it is mounted in the head tube relative to the surface to cut/engraved.

There are a number of videos at SarbarMultimedia on youtube - start areound video 150 thru 173 for lots of info on lenses.

Gene Uselman wrote: Tue Dec 03, 2019 I don't know if anyone has turned you on to Russ's videos? We have a partial inventory of his youtube vids, he answers most of the initial questions that we all have. He is how most of the members find out about us, he rarely participates but does endorse the forum and we maintain communications behind the scenes. He is up to 175 vids now, getting more and technical, the early ones are a good place to start. https://www.youtube.com/user/SarbarMult ... jreload=10

That I have!! It's how I found this forum. I actually have his videos playing on a big tv while I am working! haha

Pete Cyr wrote: Tue Dec 03, 2019 Have you ever played with a magnifying glass to burn a hole in piece of paper or something else.....the focal distance is the equivalent of adjusting the magnifying glass to concentrate the sunlight to burn. With the laser you are adjusting the hieght to concentrate the infared energy developed by the laser to burn. Some times it is advantageous to de-focus the beam - all depends on the process you are executing.

The focal distance is a function of the type of lens and where it is mounted in the head tube relative to the surface to cut/engraved.

There are a number of videos at SarbarMultimedia on youtube - start areound video 150 thru 173 for lots of info on lenses.

That part makes sense. My brain is just trying to comprehend how you go about testing/figuring out the best distance to use? I would assume there is a method and not just guess and check???

Matt Stark wrote: Tue Dec 03, 2019

Pete Cyr wrote: Tue Dec 03, 2019 Have you ever played with a magnifying glass to burn a hole in piece of paper or something else.....the focal distance is the equivalent of adjusting the magnifying glass to concentrate the sunlight to burn. With the laser you are adjusting the hieght to concentrate the infared energy developed by the laser to burn. Some times it is advantageous to de-focus the beam - all depends on the process you are executing.

The focal distance is a function of the type of lens and where it is mounted in the head tube relative to the surface to cut/engraved.

There are a number of videos at SarbarMultimedia on youtube - start areound video 150 thru 173 for lots of info on lenses.

That part makes sense. My brain is just trying to comprehend how you go about testing/figuring out the best distance to use? I would assume there is a method and not just guess and check???

There is only one focal distance for a given lens. So unless you're changing lenses, the correct focal distance (from the lens to the thing you're lasering) isn't going to change. The thing that DOES change is the thickness of the material (0.25" oak today, 3mm acrylic tomorrow), so you have to move the bed up or down to achieve the correct distance to the lens. I made a little gauge out of acrylic that fits between the bottom of the nozzle and the material being cut.

To determine the correct distance for a lens, do a "ramp test". Let me know if a search of this forum for "ramp test" doesn't reveal any results.

Matt Stark wrote: Tue Dec 03, 2019 That part makes sense. My brain is just trying to comprehend how you go about testing/figuring out the best distance to use? I would assume there is a method and not just guess and check???

in rdworks/LB, you draw a simple line or basic shape. adjust power to low and speed to something low also (so you are sure there is no problem regarding vibrations,...)

select a basic medium which will mark easily, like MDF or cardboard. fire!

the shape is drawn, the cut/mark line will be more or less large. then you up or down the table and fire again (do not move more that 1 or 2mm in Z at the same time). if the line gets larger, you are in the wrong direction, if it's finer, you are in the right direction.

in most machines, the distance between nozzle and material is <1cm, so there is no point trying more than that, except if you can not get a good result otherwise.

process by trial so you have a fine line (around 0.1mm large, not more than 0.2). if this is burning too much reduce power. if it does not mark augment power.

once done, you can use this level (*) to cut a small "stair" gauge (i'm pretty sure there is a file with the design somewhere on this forum), where each step is 1 or 0.5mm high (or whatever inches equivalent if you live in this part of the world without metric), and redo the calibration, but this time you have the gauge to really measure the distance between the top of your material and the bottom of you laser nozzle.

chances are you got a small part that indicates the desired height with you machine. (it may not be obvious, this is probably a small acrylic piece without nothing special)

i heard there is a feature in LB that allows to test various focal heights, but i never used it.


(*) do not try really cutting anything until you have found the focal, or you will just burn awfully the material but probably fail to cut correctly.