Industrial laser cutter-cost of ownership?

Hi guys,

So I'm pondering getting a large laser cutter. As in 48x120 sheets, .190" thick in aluminum. So not a desktop toy.

This leads to questions:
A) what's the minimum wattage I need to get through .200" aluminum? (It'll be 99% 6061, with the occasional run of .190 stainless.)
B) Any recommendations for brands to look for on used machines?
C) Any recommendations for issues to watch out for on used machines?
(I'm thinking used for two reasons. A) price, and (B) this will be for our in-house production needs, so it doesn't need to crank quite as fast as a job shop does. So a slightly older (and cheaper) one will be a good place to get our feet wet. Or at least that's my theory. Am I wrong?

and then the big one:

D) pitfalls, boobytraps, and unexpected costs of ownership. What does it really take to keep that wheel turning?
Power and gas I grok, but what else do they eat besides money? (Laser heads? Maintenance calls? Etc???)

What's the real cost of ownership on something like that?

Thanks,
Brian

CO2 will use a lot more electricity than fiber for sure. 4X? I have not tried .190 aluminum with 1000 watt fiber, but easily cut .125 with oxygen assist gas. Kerf is .004. Cut a .125 hole and the slug may not drop out until you tap the sheet.

I guy i know has a 5000 watt laser
He changes out the mirrors and lenses from time to time.
He also had to but a nitrogen generator as he uses a lot of nitrogen during cutting.
I don't know what other gasses he uses besides oxygen.
Overall compared to a CNC mill/lathe i would think the maintenance isn't too bad

If buying used check how many hours are on the laser tube, vs MTBF.

When you decide to go Laser be very careful with used equipment, from what I have seen at equipment garage sales is machines that are being sold just at the beginning of problems. I always enjoy when a seller states that they just spent 10 grand on repairs in the last month, so it's good to go, well what it really tells you is that it's time to sell.
Generally a bazillion operating hours.
Call around to several laser manufacturers, there sales/tech people that are generally great information sources.
Also can be good sources for used equipment, our last table was sold on our shop floor as a trade through the new equipment dealer.
Buyer got to see it operate and talk to the machines operator since it was new. lots of hours but working great just a technology upgrade.

Thanks guys, food for thought.

Especially about the 200,000 mile trade ins.
I'm definitely going to chat up anybody who'll talk before I jump, especially this year.

Next question: I worked with some of the very early cutting lasers, back in the day, and they were about 1% efficient. So (then) a 3KW laser had to be built right next to the university power station, and they could only run it at night, on a direct connection about the size of my leg. (I don't remember exactly what the power was, but the fuses were 600V, 90 amp, and it ran in 3 circuits, at least.)
Clearly, they've gotten better, but does anybody know how to figure power needs/usage for a 3-4 Kw machine now?
Next question: how to figure gas usage? Some of our current stuff is done with shop air, but some of it is N2. How do you figure the gas usage?

Thanks,
Brian

If you're looking at cutting Al and SS, don't rely on a machine's capabilities in mild steel to guide you. The reason being that you don't use O2 (as in mild steel) as an assist gas, but rather N2. In mild steel the O2 is part of the cutting process. In Al and SS, the N2 is only there to evacuate dross; you are at the mercy of the beam's power to do the actual cutting.

I've spent almost 20 years around -mostly- Trumpf CO2 lasers. To give you a ballpark idea of capabilities, Trumpf 4kW machines cutting limitations are: Mild - 3/4"; SS - 1/2"; Al - 3/8". The one Mazak 4kW we had was the same. You can sometimes push those limitations, but it comes down to how slow are you willing to go, how much heat can you pump into that part, and how bad of edge quality are willing to accept.

As far as brand names to look for, Trumpf is arguably the top-dog. Other top tier brands are Mazak and Cincinnati...I know I'm forgetting a couple more.

Things to look out for; that's tough. Most of the things that would tell that story are either buried deep or you don't have the expertise to evaluate. I guess I'd look for the normal signs that it was well cared for and try and get maintenance records. I've pondered this before; most anyone with some machining experience and/or mechanical aptitude can judge the "worthiness" of a mill or lathe. A laser is such a different beast...I don't know a good way to go about judging a used machine. Especially the resonator. I doubt there's a person on earth that could give you a good estimate of how much life it has left without an extremely deep dive into it.

Other than the consumables you mentioned, lenses and nozzles would be the most common (and relatively "cheap"). If we're still talking CO2, you'll have mirrors that can be cleaned for a quite a while, but will eventually need replacing (maybe starting the day you buy it).

If you know someone who knows lasers, pick their brains until they bleed. And do not buy one without watching it operate on multiple different materials/thicknesses unless you unequivocally trust the seller.

Alberic said:

Next question: how to figure gas usage? Some of our current stuff is done with shop air, but some of it is N2. How do you figure the gas usage?

Thanks,
Brian

Click to expand...

I have a Trumpf gas usage chart...somewhere. And a spreadsheet I used to show our estimator how much more N2 we used than O2. I thought I had them at home but they must be at work. If I can't find them here this weekend, I'll post them on Monday when I get to the office. PM me if I forget!

Schmidty:

Outstanding info. Many thanks.

Looking forward to the O2/N2 spreadsheet. That sounds very useful.

Regards,
Brian

Alberic said:

Schmidty:

Outstanding info. Many thanks.

Looking forward to the O2/N2 spreadsheet. That sounds very useful.

Regards,
Brian

Click to expand...

all depends on thickness and material cut, you could easily be in the 30-70CFM range for gas usage. and still near 100K for a used laser.