Black on stainless settings?

[Morgan Jackson]

Hi folks.

I searched, I promise, but in this case I got too much information but couldn't find the relevant info.

I am trying to put a dark black mark on some stainless. I don't know the grade.

So far I have been able to get either a "translucent" very smooth black, or a rough texture brownish mark. The problem with the black is, it's smooth which is good, but if you look at it on a right angle, it's translucent and as you get off angle it becomes very black (cool effect, but, not wanted! :) ) . The textured mark is colored/dark at any angle, but it's a) textured and b) brown.


What am I missing?

As always, thank you all!

[Gary Hair]

"What am I missing?"

You are just missing the exact setting for your machine and that particular metal. No two machines are exactly alike and no two pieces of stainless are exactly alike. I spent hours systematically going through settings and ended up with an awesome array of color on the test pieces I had available. The tests were done using 1/8" squares and keeping all settings except one the same for every variation of another. When that was optimal I would pick another setting and go through all variations with it. The good news is that I had great settings for 1/8" squares on that material. The bad news is that when I enlarged the size of the image or switched grades of stainless, the settings were pretty much useless. Black was the most consistent though, and I had about 6 different combinations that would work equally well with slight differences in how black it was and whether it was best straight on or still ok at angles. Keep experimenting and you'll find your settings. Keep in mind that Cermark on a CO2 will always beat fiber in both time and results. Nobody has made money with any image larger than about 1" using fiber for coloring, especially if there is more than one piece to mark.

[Kev Williams]

Get the darkest black with the least color shift and call it a day. Even Cermark changes shades when viewed at angle. A few days ago I was facing the same issue with a couple of small pieces of SS. I'd gotten what looked like a nice black, but with my clamp lamp shined on it, at an angle it had a slight purple tint. Made a small change, and it lightened up- another change darkened it some. After maybe four or five more tweaks I got a very deep black even with the lamp shining on it. But the 'holograph' effect was still there, although very minimal. While running these tweaks, I found that changing the frequency only ONE point would make a noticeable difference sometimes. Also, ONE percentage point of power made a visible difference, sometimes.

The translucent 'holograph' effect happens because, even at lower power and higher freq's, the laser cuts grooves on the surface, and the edges and bottom of the grooves reflect and refract ambient light, and how your eyes see the reflected light depends on the angle you're viewing it at. It's the same phenomenon that allows those plastic things to show 2 different pictures by looking at it at different angles.

You can maybe reduce the effect with multi-hatching, but that just eats tons of time.

Once (in 3 years!) I got a Cermark looking black, happened on this stainless bottle opener, but I've never been able to repeat it.
It looks like Cermark but I swear my Triumph fiber did it! --you can tell from detail a C02 didn't do it, and there IS a tinge of brown to it, especially around the edges, but very slight. And it's a flat black rather than the glossy annealed black...
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I do remember I was using fairly high power and frequency with fairly wide hatch fills. Could be the stainless itself was more' receptive' to the fiber? Such is life with these things!

[John Lifer]

I agree with the experts above. I've even done some that I would swear weren't etched from the angle I was looking at them while on the table. I usually make sure I do two passes at different non opposing angles, (not 90 and 270, but 90 and 180..... Seems to help a bit. And it seems no two pieces of SS are the same.

[Morgan Jackson]

Thanks guys.. I have been mulling this in my head and forgot you all aren't mind readers! ;)
It's a Tykma 20w Fiber
the settings that I liked (so far) were 2 passes, 200mm/s, 35% power, 125 frq and .02 line spacing.

I also HAPPENED to be trying all my efforts with a consistent size font/block and didn't realize that when I made the image larger my settings would go to garbage.. I was just trying that and realized that's exactly what happens.. and grew rather frustrated!

My laser appears only willing (able) to produce black and occasionally some hints of a red or blue when viewed in the right light. But perhaps I need more time spent playing with settings and some of those colors will become more distinct. As is, they are "hologram-y" colors. Only a color as you shift the part.

I do happen to have access to a decent CO2 laser.. and perhaps.. that's the real answer. It just feels like I am "thhhhaaaat" close and/or keep dancing around the answer.

I do appreciate the commentary!

[art olin]

Thanks guys.. I have been mulling this in my head and forgot you all aren't mind readers! ;)
It's a Tykma 20w Fiber
the settings that I liked (so far) were 2 passes, 200mm/s, 35% power, 125 frq and .02 line spacing.

I also HAPPENED to be trying all my efforts with a consistent size font/block and didn't realize that when I made the image larger my settings would go to garbage.. I was just trying that and realized that's exactly what happens.. and grew rather frustrated!

My laser appears only willing (able) to produce black and occasionally some hints of a red or blue when viewed in the right light. But perhaps I need more time spent playing with settings and some of those colors will become more distinct. As is, they are "hologram-y" colors. Only a color as you shift the part.

I do happen to have access to a decent CO2 laser.. and perhaps.. that's the real answer. It just feels like I am "thhhhaaaat" close and/or keep dancing around the answer.

I do appreciate the commentary!


stainless-steel -SUS annealing - laser set up range depends on the laser (YAG, Fiber Q-switch, Fiber -MOPA, Fiber MOFA, Green or UV) and the rest of course depended also on the resolution of the lasering (1μm, 2μm, 5μm, or more 35μm ….50μm…) and line intervals but in general specs are in a rage of:
1 pass, no repetitions with intervals 0.01
YAG
20kHz -25kHz speed 20mm/s-100mm/s and power 80%-90%
Fiber Q-switch Fiber -MOPA Fiber MOFA
60kHz -100kHz with speed 100mm/s-500mm/s and power 80%-90%

Green - 60kHz -100kHz with speed 100mm/s-500mm/s and power 70%-80%
YVO4 - 60kHz -100kHz with speed 100mm/s-500mm/s and power 80%-90%
UV - 60kHz -100kHz with speed 100mm/s-500mm/s and power 35%-50%
You need to make couple of tests for your kind of laser and material - which will give you the color you like the best, but for sure you need to be between the provided specs and numbers.
Kind Regards

[Morgan Jackson]

Art:

Thank you..I forget about the different power sources making a difference.

my Tykma is a MOPA and some of my "good" passes dance around your settings.

I found best results in the 100 to 150 khz range. Below 100 and it starts to cut. Above 160 and black fades to grey. What I hadn't really though about was slowing down the passes at a good black generating wavelength.

I appreciate the input!




stainless-steel -SUS annealing - laser set up range depends on the laser (YAG, Fiber Q-switch, Fiber -MOPA, Fiber MOFA, Green or UV) and the rest of course depended also on the resolution of the lasering (1μm, 2μm, 5μm, or more 35μm ….50μm…) and line intervals but in general specs are in a rage of:
1 pass, no repetitions with intervals 0.01
YAG
20kHz -25kHz speed 20mm/s-100mm/s and power 80%-90%
Fiber Q-switch Fiber -MOPA Fiber MOFA
60kHz -100kHz with speed 100mm/s-500mm/s and power 80%-90%

Green - 60kHz -100kHz with speed 100mm/s-500mm/s and power 70%-80%
YVO4 - 60kHz -100kHz with speed 100mm/s-500mm/s and power 80%-90%
UV - 60kHz -100kHz with speed 100mm/s-500mm/s and power 35%-50%
You need to make couple of tests for your kind of laser and material - which will give you the color you like the best, but for sure you need to be between the provided specs and numbers.
Kind Regards

[Kev Williams]

FWIW, my 30w Triumph's good annealed black happens with my 150mm lens .002 to .005 hatch spacing (sometimes I spread it out but never more than .01), 300 speed ave, 33% power and freq set at 72. --freq set to 71 or 73, not quite the same, very finicky...

My other 2 machines use similar settings, but not the same-- they're all different...

Your MOPA like means MY settings won't be worth a flip...