Max Depth on 30W Fiber // Deep Cutting Routines

[Chris DeGerolamo]

As to not hijack from others, aside from a brute force standpoint is there a method to deep engrave on metals that is considered standard? Point of clarification: I am engraving my Glock slide. So far I can get about a 0.5mm before the machine seems to "bottom out". I would love to hear any input. Being as that I ran many hours of passes today I was able to test just about everything...hatch type, spacing, speed etc. It seems that depth [on 30W fiber] is achieved at around 250/200 mm/s at 100p with clean-ups in between. What do you all think?

[Gary Hair]

You can definitely go deeper than that, I have many times. It could be that you are at the bottom of the focal range of your lens and it is so slow to go any deeper that it seems like it has bottomed out. I lasered a 1/2" square areas completely through a piece of 1/8" stainless just to see if I could. It was a long time ago and I don't have the settings saved, but it was something like: 100% power, 100 mm/s, 30 Freq, and two hatches with auto-incrementing hatch angle (I forget what that's called in the software). The closer you are to dead center below the lens the easier it will be to get deep, otherwise you are trying to cut through at an angle and making any focus problems much worse. Oh, and the piece will be very hot - even a 4" x 6" piece will heat up a lot getting deeper than .01". I may, or may not have, burned myself after it was done...

[Kev Williams]

"Auto Rotate" ;)

This is my 30w Triumph engraving a steel seal mold a couple years ago, when it was engraving all whacko-
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Look close on the mold itself, the first 5, the 9 and the -01 all have visible 'other' engraving. That was a fun time...
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But- it still managed to engrave to somewhere between 3 & 4mm deep. It can be done :)

[Chris DeGerolamo]

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This is where I am at currently. I would love to drop some weight and even punch through some windows to expose the barrel... My autorotate seemed to be stuck on 10 degrees yesterday so I'll certainly need to revisit. Yes, it got warm, and we always strive to work dead center of the table. Will post back results when/as I am able. Today I need to get some billing done.

[Kev Williams]

you're every bit as deep there as the mold engraving if not more. Not sure you'll ever get clear thru that slide, tall order for a 30 watt light bulb ;)

Auto rotate- sometimes it doesn't work and it's usually because it's conflicting with some other variable, make sure the edge offset, line reduction etc numbers are zeroed out. You'll know the rotate is working when you revisit the hatch routine window and the 'angle' number is in the thousands :)

When I use auto rotate I usually set it to a goofy number like 31 degrees, my thought being the hatch lines will rarely repeat/engrave on top of each other, or at least until the original metal is long gone. The Tykma 'how to run a fiber' manual states in many places to run many loops when deep engraving, and in my mind that's counter-productive; when you engrave the same line over and over you get to a point where the metal slags up and just falls into the cut. I proved this to myself went trying to cut a .030" thick SS sawblade for a customer, after so many passes it simply would not go any deeper. If I autorotate a crosshatch 30 degrees, every 3 passes the hatch angle repeats, but at 31 degrees, the hatch angle is skewed 3 degrees from original, and it will take 26 more passes to hit the original hatch alignment. And by then it won't matter. Doing this, the laser is always cutting 'fresh' material. Just seems to me to be more efficient than engraving the same lines 30 times...

[Chris DeGerolamo]

Okay so, back to this. I mic'ed the top of the slide, ~2.25mm. I have since punched all the way through with surprising little time/effort. I changed my routine and went with 100mm/s as suggested. Edge is good, no burrs.

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[Tony South]

https://www.youtube.com/watch?v=T1pKIv--Nh4
check out what this guy has to say. I want one of those lenses for my 50w. he is cutting through glock slides with a 20w.

[Chris DeGerolamo]

https://www.youtube.com/watch?v=T1pKIv--Nh4
check out what this guy has to say. I want one of those lenses for my 50w. he is cutting through glock slides with a 20w.

This guy is only a few hours away; been watchin' his videos...good stuff. Note he admitted his 20W Qswitch was heavily modded. Thanks for posting.

[Trey Tull]

How does one heavily modify a laser? Also, any idea about that lens?

[Tony South]

How does one heavily modify a laser? Also, any idea about that lens?
I have messaged that guy on Instagram and asked him what his heavily modded laser consists of. He told me he had Upgraded software and that huge lens. so much for heavily modded haha.

[Matt Schrum]

I have messaged that guy on Instagram and asked him what his heavily modded laser consists of. He told me he had Upgraded software and that huge lens. so much for heavily modded haha.

I came across a few of his videos yesterday and his lens is sizable. Any guess as to what makes that lens different than the standard f-theta lens or why it is so large? I've done some sleuthing and can't seem to find any fiber laser lens options that look to be that size.

[John Lifer]

Hmmm, video above is private now. no link.
I went pretty darn deep on my glock slide with my 20 watt, not anywhere through it though. (as deep as the normal rear grooves.)
It just takes a while. I can't see a lens helping any.

[Matt Schrum]

Hmmm, video above is private now. no link.
.
That's unfortunate. I literally just watched that video last night and left a comment on there asking about his lens. Then he turned and made the video private in the last 24 hours. I agree with you, I'm not sure how much a lens makes a difference-- but it would have been nice for him to share some more information instead of just shutting up and deleting the only video that really showed the lens he was bragging about so much. Oh well, whatcha' going to do.

[Kev Williams]

The lens may have more to do with it than we may think. I point to my three RF C02 machines as evidence; the 2" lens in my LS900 will make Cermark a very dark gray, very close to pure black. The lens in my LS100, no matter what I do, will produce a dark gray several shades lighter, very noticeably not even CLOSE to pure black. I bought a 2-1/2" lens for the LS100, produces the same exact results. However, if I put the LS900 lens in the LS100, I get the same near black results as the LS900. My GCC Explorer, very dark also. My 80w glass Triumph, I can GET black results, but only under low-power conditions, enough that the Cermark won't fully fuse to the metal. The LS100 lens, even at low power won't turn Cermark black...

So just based on my own not-to-scientific results, I could believe a simple lens change COULD make a difference with fiber machining--

I also wonder if the different software could be manipulating the beam frequency? Lower frequencies seem to be much better at full-on machining of metals than higher freq's, and it really doesn't seem much of stretch for the software to be able to 'tell' the controller to fire the laser at lower frequencies, such as cutting the freq in half, allowing my 30w fiber to fire as low as 15kHz rather than 30kHz... ?

[Chris DeGerolamo]

Hmmm, video above is private now. no link.
I went pretty darn deep on my glock slide with my 20 watt, not anywhere through it though. (as deep as the normal rear grooves.)
It just takes a while. I can't see a lens helping any.

I have punched through Glock slides with our 30W. Takes a while though. As far as new serrations, you gotta run successive passes at 100mm/s or so at full power to get the laser to bite down. Clean-ups in between for sure. The cool thing about this task is changing the hatch density etc as you go to see what works for you and your machine. HTH.

[Matt Schrum]

The lens may have more to do with it than we may think. ....

I think I found the type of lens NCEngraver was referencing in his (now private) video. Based on what I recall seeing, the Alibaba link below to a telecentric F-Theta lens looks quite similar to the lens he was bragging about in his video. For what it is worth, NCEngraver responded to me saying they provide lens info to customers that buy fiber lasers from him (and he didn't want competitors, so he made the video private)-- so I told him I'd like to buy one, at which point he said they don't sell fiber lasers, but are thinking about maybe selling them in the future. Well, phooey, that's not helpful at all.

Regardless, from what I can find, the standard F-Theta lenses that come with our eBay fiber machines make sure the beam is in focus-- but the beam still exits the lens at quite an angle as you get to the edges of your work area. A telecentric F-theta lens also ensures that the beam is close to perpendicular when it exits the lens (and not at a steep angle). I've currently got data sheets and am waiting on pricing through Alibaba on the lenses to see what they run. I've seen basic listings from $100-$1000 for this type of lens, so I'll be curious to see what the total cost is (for reference, the default lens that ships with our eBay machines seems to be in the $50-$100 range on Alibaba).

The current data sheets I have indicate a pretty small working area (2" x 2" or less)-- but some of the other listings indicated working areas closer to the 4" x 4", etc.

https://wavelength-tech.en.alibaba.com/product/60750530612-805881715/Telecentric_lens_1064nm_laser_F_theta_scan_lens_Op tical_glass_TSL_1064_40_100_D25.html?spm=a2700.122 43863.0.0.2ce83e5foTyZEI

one more link
https://www.alibaba.com/product-detail/telecentric-lens-F-Theta-scan-lens_60757863438.html?spm=a2700.details.deiletai6. 2.71ac35b7LH25v3

[Kev Williams]

Well, the beam can only exit at a right angle up to the physical diameter of the lens glass -- then what?

So then, a lens with 4" diameter optics can ONLY engrave within a 4" diameter circle. A typical 4"/100mm lens gives you a 4" SQUARE working area, which is a substantial increase over a 4" circular area, diagonally you gain over an inch of work area (depending)...

So it makes sense a 2x2" work area of a TC lens would be practical due to the overall lens size. I have a 75mm 'normal' lens, which renders barely over 2x2" workspace, and it's an animal, VERY aggressive... If the focal distance of a 2x2 TC lens the same as my 2" lens, the power density of a focused perpendicular beam, wow...

Nice as it sounds, for my type of work, I couldn't justify the expense and limitations...