Metal Cutting Laser... yes another thread...

[Pieter Swart]

Hi Folks,

So now that we have the 100w co2 up and running ( iffy at best, but finally ), My wife wants to start at her next conquest.

I am researching, but coming up with half answers spread over 100's of threads... so far only bits and pieces... all I want, is 1 whole truth, which is better than 10000 half truth's( like my dad says), so spill it... lol


This is what my wife is after ( still after )

A laser: gantry or galvo, co2, fiber, Yag etc...

that can quickly cut, through metal specifically metal cards , sheet metal and stainless steel ( I assume that copper or bronze might be in her equation also). Items with high reflectivity

If this topic had been discussed in depth, please point me in that direction, but if not, please advise us on the best options possible.

we have designers asking us about stainless steel cut outs for wall mounting and so far I can't answer any of their questions, and pointing them to the nearest metal shop... I would like to change that answer to "sure we could do that "...

(so at this point I would like a fiber laser for speed and ease of use for engraving, but my wife wants a metal cutting laser... best of both worlds? is that even possible?)


As always, We enjoy your responses and soak up every morsel of info we can get.

[Pieter Swart]

I found this thread, but there must be updated info by now...

http://www.sawmillcreek.org/showthre...age2&p=2432216

[John Lifer]

Called a plasma cutter. I'm guessing, but a fiber to cut any thickness will be upwards of 100 watts. I tried​ cutting thru some brass shim stock the other day. 0.005 inch thickness. Thin. My 20 watt would do it. Just it is a bunch of minutes and probably over a hundred passes to do it. And with brass, it warped a lot. Made it worthless trial. So I'll stick to Engraving with it.

[Keith Outten]

You might try going right to the source. Kern Laser has options for their CO2 lasers for cutting metal.
You can purchase a plasma CNC machine but that won't provide the fine detail that a Laser Engraver will, it sounds like that is what you want.

[Bill George]

I think your primary questions should be how thick a metal and how much is your budget? The Kern folks have some nice machines, but paying for them by making wall hangings might be a stretch.

I see a plasma cutter was brought up, had one a PlasmaCAM and it depending on the torch you installed could cut up to 1/2 inch or 13 mm, I had one that would do 1/4 inch or 6 mm. Worked well and even with a water table and exhaust system the metal dust was all over. Then you have the handle the metal, 4x4 foot pieces even 20 gauge stuff was heavy to move and store. I had $12000 or so invested.

[Scott Shepherd]

And let's not forget Dave's stories about the Chinese metal cutting lasers not using the necessary safety devices that prevent you from blowing up the entire block. Maybe Dave will chime in.

Personally, after Dave's real life stories about people being killed and seriously injured, I wouldn't even consider a Chinese metal cutting laser. That's just me. You might feel luckier than I do.

[Michael Henriksen]

If you want to cut all those different metal you should probably look for a machine with a 500W nLight source. I recently got a quote for a 1325 metal laser with a 700W nLight source and the price was USD 41000. There is a 6040 size machine available but I don't expect the price to be much lower.

[Kev Williams]

for what it's worth- a few months ago one of my customers brought me a 2" diameter stainless saw blade. He needed it 1-3/4" diameter. It only measured .010" thick so I gave it a try with the fiber-

In the end it took several minutes, ran the circle several hundred times and it never did cut clean thru, and warped the crap out of it even though I had it sitting on a wet shop rag. When I finally gave up, I found slag was all that was holding it together and I was able to 'snap' the outer ring from the center. But it was burnt, burry, and because of the warping it wasn't really round either. I probably would have had better luck running 3 or 4 different diameter passes, .01mm apart or so, and maybe pausing once in awhile to let the metal cool. Bottom line, I probably could've done it faster with a bench grinder...

[Gary Hair]

In a word - waterjet - or is that two...

[Dave Sheldrake]

A direct import chinese gas assisted metal cutting laser is a bomb, it is likely to kill you, relocate your house and half your street as well as consume gas faster that my cats go through cat food (I have 28 cats)

A direct import Fibre cutter is going to come with problems...fibre problems cost a lot to fix and don't plan on getting any help from china

US/EU made gas assisted cutters eat Oxygen, the Kern for example with a 400 watt source is a touch under $180,000 the 250 watt is cheaper but requires Oxygen to cut any metal , the 400 watt won't really do much in the way of commercial metal cutting at any speed unless you use Oxygen so you are back to gas costs. (CO2 is about as inefficient as it gets in metal cutting lasers) (My 7.5kW CO2 won't keep up with the 3kW fibre sat next to it)

A US supplied fibre is expensive, figure on $100K for a 500 watt and upwards (go above 1,000/1,500 watt and they start costing the same as a small house)

If you want to do metal cutting commercially at any speed with decent quality, start thinking 3kW to 4kW Fibres and ball parks of $1 million upwards if you really must use a laser.

[Bill George]

consume gas faster that my cats go through cat food (I have 28 cats)

Dave are you still remodeling that large stone house? Maybe you need 28 Cats... to keep the mice at bay!

[Chris J Anderson]

I have recently purchased a 300w chinese fiber laser.
It cuts 2mm stainless no problems.

It has been a nightmare to set up and get running. Soon I will post the whole saga in a thread here. Suffice to say if I didnt have a clue about electronics / automation I would never have got it going.

It doesnt leave a nice edge finish unless you use nitrogen in which case it is way too slow on anything over 0.5mm thick.

It wont cut aluminium or brass. I can only get mine to mark the surface, just makes a mess. I am guessing you need to be up in the 2000 watt plus area to cut all metals nicely.

So to the OP, if you wish to cut different metals, you will need to spend big $

Dave, do you have a link to your information about the dangers of gas assisted laser ?
I am presuming this wont apply to my 300w fiber ?

Cheers to all...
Chris

[Dave Sheldrake]

Dave are you still remodeling that large stone house? Maybe you need 28 Cats... to keep the mice at bay!

Yea still working on it last year was a disaster though with Karen being diagnosed with Cancer so I didn't get much time to do anything, she's good now though so back to working on the house when time allows

Dave, do you have a link to your information about the dangers of gas assisted laser ?
I am presuming this wont apply to my 300w fiber ?

It's the Oxygen assist that's a problem Chris, many Chinese machines don't have intrinsic electrical safety, the gas lines are whatever they pull out of the box (read the cheapest) Western and Japanese supplied machines have sealed cabinets with no path for the Oxygen to get into the electrical compartments (see Apollo 1 for what happens), extraction on Chinese imports tends to be basic and little better than the stuff used on the more normal Chinese CO2's, smaller non pulsed CO2's aren't really the right lasers to cut metals, they simply don't have the Photon energy or absorption rates in metals leading to a need to change the actual mechanism of cutting to more of chemical reaction rather than a disassociation of the metal.

They are in effect little more than an Oxy-Tet kit heating the metal and firing Oxygen at it to cause the reaction and cut, a 300 watt Fibre is in the void, more than you need for engraving on a Galvo but too little to do much cutting with other than shim stock.

Of course any high pressure gas is dangerous (sub dermal embolosis) once you hit 60PSI up but Oxygen is a breed apart...it makes stuff that is normally inert...flammable ... VERY

In Oxy rich environments (such as one I went to in India) the gas can hangup in clothing for 24 hours, especially cotton surprisingly, that never usually ends well.(It didn't end well in India, the place I was at was washing three operators off the wall with a fire hose 3 days after it went wrong and put a 4th in a wheelchair for life)

Don't get me wrong, there are GOOD Chinese gas assisted Metal cutters that are imported, modified then retailed but for something that could relocate my house I tend to be very careful.

99% of the problems don't really apply to your Fibre Chris unless you use tanked Oxygen on it, then I would be a LOT more careful about doing so

[Rodne Gold]

I got quoted $50k for a 1kw fibre , 2m x 3m .. I decided I didn't want to start a new business what with large scale cutting and material handling and gas and developing a market etc.. so I bought a set of hifi speakers instead.

[Michael Henriksen]

I've been doing a fair bit of research on fiber laser cutters (and pestered Dave with a lot of questions). I find that the Chinse vendors I have been in touch with have been quite up front about capabilities, gas consumption etc. A 700W nLight source seems to be a decent choice if you don't expect to cut thick stainless. It will cut thin brass, copper and alu. A 750W Raycus source will not do that. I'm looking at a fiber laser but my main intended use is not to cut parts on a a sub-contractor basis. There is no money in that as I won't be able to compete with the guys running 3+KW machines. I would mainly use it to cut my own designs and cut decorative objects for a couple of my customers. It's low volume work that the big guys won't touch (or charge a high setup fee for) but I can charge a decent amount for the work. I have looked at plasma but it won't cut the fine details I need.

If I get one, the first thing I will do is replace the oxygen gas line with something of good quality. I've seen clips of Chinese machines using what looks like normal clear PVC hose. Scary!