Fiber laser deep engraving on aluminum

[Marianne Rusche]

Hi,
I have a 30w fiber laser engraver and I am struggling with getting a smooth edge on the letters I engrave on aluminum. I engrave mostly pet tags and the aluminum is 14 gauge. No matter what parameters I try, the edges always have burrs or slag. Before I purchased this laser, I did a lot of metal stamping. Of course it is very deep and smooth. I was hoping to find parameters that would get a similar depth and smooth feel with my laser. I can come close if I go very slow with a high frequency. However, time is also money.😣 Does anyone have any suggestions as to what I could try?
Thanks so much,
Marianne

[Bert McMahan]

I don't have a fiber but it might help to post some pictures of what you're making and what your results are.

[Marianne Rusche]

Ok good idea! I’ll get some pics off soon! Thanks!

[Marianne Rusche]

Hopefully this picture uploaded. Around the edges of the letters it’s tough and sticks up a bit. I have to sand it down to get it smooth. It’s just one more step that I would like to eliminate. Hopefully there are some parameters that I can try that will help to smooth out the burrs on the edges.
Thanks,
marianne

[Gary Hair]

You need to use high speed, high frequency and low power. It will take lots (100's) of passes but they go so fast that it ends up being fairly fast anyway. I have engraved tons of AR lowers and there was virtually no burr or debris around the edges when I did it this way. For an extremely deep engrave I would do the first 1/3rd this way, then the rest using high power, slow speed and low frequency to really hog out the material. I'm not at my computer but I think I used 100p, 100s, 30f for fast hogging out, then 50p, 1,500s, and 60f for cleaning/first passes. You can also use several hatches to make things go a bit faster - one at 45, one at 90 and one at 135.

[Marianne Rusche]

Gary,
thanks! I have been doing 35 loops, 1500 speed, 100% power, and 20 frequency. One hatch at 90 degree (cross hatched) and .02 line space. It’s ok but I still have a little clean up on the edges. I’ll try tomorrow to do many more loops with faster speed and see what happens! Thanks so much,
marianne

[Neville Stewart]

I’d use a different hatch pattern on letters with internal elements too, use interrupted hatch.also run a few dozen perimeter passes. See your “O”.

[Bill George]

Gary,
thanks! I have been doing 35 loops, 1500 speed, 100% power, and 20 frequency. One hatch at 90 degree (cross hatched) and .02 line space. It’s ok but I still have a little clean up on the edges. I’ll try tomorrow to do many more loops with faster speed and see what happens! Thanks so much,
marianne
You need to re-read what Gary posted. Your using the wrong speed, wrong power and frequency. He does it everyday and he knows.

[Marianne Rusche]

Gary,
Thanks! I tried again using your parameters and it was much better! I still had a tiny bit of slag on the edge but it wasn’t bad at all! I’ll get a picture up soon! My next issue I’d love to resolve is to get the letters really dark along with deeply engraved. I know I can get stainless steel to engrave letters that are really dark. Is it possible to get deeply engraved letters really dark on aluminum? Right now I am inking the letters with a patina ink. I’d also love to be able to skip that step as well!! Thanks for any additional help!
marianne

[John Lifer]

No, not in my experience. The best I can go is get a 'frosted' grey look by using wobble. Which brings in other issues with the engraving. Does give a way better look on bare aluminum, but not anywhere near black.

[Marianne Rusche]

John,
yeh I’m thinking that really dark black just isn’t possible on aluminum. I can get a somewhat dark grey but that’s about it! I was hoping that there are some settings that I just haven’t found yet that could work! Thanks, Marianne

[Kev Williams]

About 'loops' and hatch routines (IMO) -- I don't do loops, because what loops do is force multiple passes of the same cut. If you have a hatch routine of 45, -45 and 90 degrees, and do 10 loops, you'll engrave 10 45's, then 10 -45's, then 10 90's. When deep engraving I've found it more efficient to cross-cut every pass. So instead of 10 LOOPS, I set the machine to do 10 REPEATS, which does a 45, a cross hatched -45 and a cross hatched 90, 10 times. I've found that getting to .005" deep in aluminum takes a few more passes doing loops. Not a big difference, but to me it's noticeable...

And then there's 'auto rotate' hatch. If you're planning on say, deep engraving a Glock slide, which will easily take over 100 separate hatch passes, give the auto rotate a try. What I do enable only one hatch, at a 7° angle, and enter a 29° auto rotate. With these numbers you're cross hatching at essentially 30° which leaves a near perfect triangle cut pattern, and rotating at 29 means the hatch angle will almost never repeat, so every cut line is never in the same place. Makes for good digging and leaves a clean bottom. Sometimes getting the auto-rotate to work is tricky, but you'll know it's working after it stops, as the displayed hatch angle at the left of the screen will be in the thousands of degrees :)

[Marianne Rusche]

Kev,
Thanks for the response! In the hatch settings, I have a crosshatch setting. I was told this is fairly new. When I click on it and use 90degrees, it cuts once vertically and once horizontally and then repeats. Is that what you mean by “repeat”? It does make sense that you wouldn’t want to go too many times in a row digging in one direction! I’ll have to look into the auto rotate. I’m new to all these settings and there sure is a lot to learn and understand. Thanks, Marianne

[Bill George]

Marianne, do not feel like your alone. EZCad is So frustrating and Hard to learn but Kev and Gary are pretty darn good at it. Just keep at it :)

[Marianne Rusche]

Bill,
thanks! Ezcad is VERY frustrating! There’s so many combinations and it seems like a million different ways to set up the parameters! I really do appreciate all the help!!!
Marianne

[Neville Stewart]

John,
yeh I’m thinking that really dark black just isn’t possible on aluminum. I can get a somewhat dark grey but that’s about it! I was hoping that there are some settings that I just haven’t found yet that could work! Thanks, Marianne
Iron in alloys allow you to get black marking. As there’s none in aluminum you won’t get black. You’ll get a dark scorch but not shiny deep black like stainless.
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[Marianne Rusche]

Iron in alloys allow you to get black marking. As there’s none in aluminum you won’t get black. You’ll get a dark scorch but not shiny deep black like stainless.
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Neville,
what you did with, “Jamie, RN” is darker than I have been able to achieve. Do you mind sharing what parameters you used to get it that dark. I know it’s not really deep black but it might be good enough. I think I might have a better handle on deep aluminum engraving but I would also love to make the letters as dark as possible. Again, all this help is really appreciated!
marianne

[Gary Hair]

Bill,
thanks! Ezcad is VERY frustrating! There’s so many combinations and it seems like a million different ways to set up the parameters! I really do appreciate all the help!!!
Marianne

There are so many variables that will give you the same results and they are usually not very intuitive. Some of my best results have been 100% by accident and not by any logical experimenting. The only exception to that is stainless steel color marking - I spent many hours doing test grids and successfully found settings to get a good range of color. The only problem is that the color you get in the .25" test squares isn't the same when you enlarge the area - a 1" square with the same settings may, or may not, give the same color. Chances are it will be a gradient instead of a solid color. That's why color marking stainless is NEVER going to make you any money! Black text is easy, when you find the right settings. Slow, mid-power, mid frequency, tight hatch - .01mm, 2-3mm out of focus, two hatches one at 45 and one at 135, two or three passes.

[Kev Williams]

Just to hi-jack a bit- this is one of my favorite pieces to show people what a fiber is capable of...

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plain old black plexiglas, the background detail, love it...

Painfully frustrating these machines can be, but it's a good pain :D

--enjoy--

[Will Howard]

How many ns is the pulse duration on your machine?... and what line space do you use?

[Marianne Rusche]

How many ns is the pulse duration on your machine?... and what line space do you use?
Hi,
I’m not sure I know what pulse duration is? I use.02mm line space
thanks,
marianne

[Darren Wilson]

Hi,
You can make black mark on anodised aluminium, however, you can not engrave past the anodic coating or you go back to dark grey.
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[Kev Williams]

This is about as dark as I've been able to get on aluminum-
394087
not close to black by any stretch but makes for some nice variables in grays-