I have an upgraded Emblaser 2 with the 10W diode laser (455nm) and the newer air assist. I’ve been trying to work out if there are any metals I could cut with it to make earrings.
I’ve done a heap of digging but believe that a combination of a “yellow” metal, low thermal conductivity, and very thin sheets may be able to be cut but I’m wanting more input before I order materials because it appears that any I might be able to cut have to be ordered from overseas and I may be way off the mark.
I was looking particularly at copper alloys such as manganese bronze which is only 35.5 W/m conductivity.
For thickness, I wanted to try 0.1mm to 0.5mm and see how long (if at all) it would take.
Any advice or recommendations would be most appreciated.
Even if you can manage it, I think your heat affected zone (oxidation, slag, warpage, etc) will be so bad that you’ll find the pieces unusable or require so much post-processing that cutting them on a scroll saw or similar would be faster and cleaner.
They start at 0.03mm. The thickest steel they manage to cut with multiple passes 0.178mm. Steel has a thermal conductivity of about 50 W/m. As I said in my OP I’m looking at a non-grey metal such as bronze which will absorb more of a blue 455nm laser and has a much lower thermal conductivity at 35.5 W/m.
Sounds like you’re all set to blaze a trail. Godspeed and report back! I’m sure others (me!) will appreciate whatever info you can supply.
Somebody always has to go first.
I spent some time as an industrial torch brazing guy and did some work with bronze castings as well as stainless steel. I can’t argue with the numbers as I don’t know, but I can say brazing bronze is far easier than SS because it SEEMS to conduct heat better. Don’t need to move the torch around as much. I can’t say for sure if it’s conducting that heat faster or slower than SS or if it’s related to other factors. Just my experience putting heat to metal.
FWIW, brazing aluminum is super finicky (almost no warning before it melts and the oxidation is hard as diamonds) and copper is so simple a child could do it.
They make good pots/pans and heat sinks out of copper the best material… also quite costly compared to aluminum.
I would think copper, maybe bronze also, would sink heat away quicker than steel. But I haven’t looked…
Again, it’s on the edges of where the laser can really do damage. A co2 is useless cutting metal… but if it’s a 5kW laser, things are a bit difference.
As these get more powerful, they will have greater abilities to do other materials…
The fiber lasers handle the issue by pulse frequency and width.
My 60W MOPA can deliver 18kW pulses… even the Atomstack MR20 can produce 7kW pulses and it’s < $1,400 US and it’s gantry mounted, no galvo…
I’ll be watching the thread… I too an anxious to see what you can do…
I’ll certainly report back but it looks like I’ll have to order from Aliexpress and wait 1-2 months for it to get here unless I find a local metallurgist who is happy to help me.
Conducting heat well means that the head applied by the laser is distributed faster across the object, which is why I’m looking for the lowest conductivity metals to try. Stainless steel is quite low, and there are some other alloys even lower, but those all have the issue of being quite reflective of the blue 455nm light of a diode laser.
And there lies the reason why even deep engraving of metals using our “blue” budget lasers is not the best of ideas.
Not to mention cutting, which requires significantly more energy and produces splatters etc.
When (not if) the beam eventually reflects back, at best the protective lens is toast (and may protect the other vital components), at worst a portion of the reflected beam damages the mirrors and/or the laser modules.
The protective lens can be replaced, AFAIK neither the laser modules nor the mirrors can.
When I eventually (probably not until the head is in its last legs) will try to cut various foils I have and can easily get, I will tilt the laser head a precalculated degree in order to minimize reflections back to the head.
The measly power/energy intensity we have at our disposal means that most of the materials liquify and pool rather than evaporate/sublimate immediately as is the case with industrial (metal cutting) lasers.
So things like surface tension of the puddle of metal for example does make calculating the “best” or “least bad” angle in order to avoid the destructive reflections completely extremely hard.
With my China Blue co2 I tried to do some stainless steel. I managed to mark it, but it cost me the lens… Burnt it.
The reflected power is actually very low since my 2" lens was focused on the metal, it was out of focus when it got back to the lens, which it still wasted. Even at a 4" focus point, twice it’s actual focal distance, it damage the lens.
I think what comes out of the lens on the other side is much less powerful as it’s acting like a beam expander. Even though I wasted the lens, no marks or damage to the mirrors.
Co2 lasers cut steel and other metals, but these are in the kW output range. I don’t think they are in power range yet to really be useful for metals.
Don’t know what you’re expecting … This is from the video using 0.025mm steel…
That’s not too bad, way better than what I expected.
Not obviously great, and IMO not very useful for most applications at this point, but at least doesn’t look like a rodent has gnawed its way through the foil.
However, at least as a someone who doesn’t use earrings, I’d say that as-is, the results could well be good enough for leafs, feathers and other more organic earring designs.
And definitely for a miniature version of those lamp shades that at least my dgeneration made in the crafts class by melting holes into a sheet metal tube with an oxy-acetylene torch or a stick welder.
Would You mind sharing the cutting parameters and the thickness of the foil?
I’d probably try cutting in an inert gas atmosphere, but then chances are that the lack of active gasses means that predictable penetration is even harder (or with low power impossible) to accomplish.
The other “solution” would probably be to use a different air nozzle and use controllable high volume airstream to aid in the cutting.
In quotation marks because the risk of splatters and damaging the lens increases dramatically.
And also because the rigidity of the gantry may not be good enough for the forces that the air stream required produces.
It was 304 stainless steel, 0.05mm. I have 0.1 to try as well.
I’d love to try that but It’s a special school. We only managed to get this because of grant money, and I’m the IT guy, we don’t have a teacher who can teach this kind of thing. I wish we could afford to have access to inert gas setups, and better equipment but that is at the whims of what grants the government decide to offer.
If the maker space program goes well (first lesson was yesterday) I’ll be searching for grants to put in an appropriate cutter and if possible inert gas etc. If that happens, I’m sure I’ll be asking here for a what I should put on the wish list.
Then I’m even more impressed, not a bad result at all.
Given the decent result with 0.05, that might be possible.
Not obviously a very practical solution for any sort of production, but substituting the air assist with nitrogen -or better yet argon(/argon+co2 mix)- will be cheap and easy enough for a test.
Providing of course that there’s a welding department or a hobbyist welder as a student or a teacher in Your school.
Unfortunately other things in life will prevent me from trying that out myself for at least a couple of weeks, but Your results are very encouraging indeed .
Inert gas shielding would help with the oxidation/discoloration, but it would slow the cutting. Air actually works pretty decent. It has enough oxy mixed with inert nitrogen to be a sorta balanced atmosphere. Enough kick from the oxy to help cutting and enough nitro to keep things from getting outta control. Straight oxy is also done, but it’s finicky and obviously not a smart choice in a non-industrial setting.
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