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Michael Lang
07-03-2008, 4:40 AM
Hi,

is anybody experienced in metal cutting. I'd like to cut sheet metal with 1/16" thickness.

What laser can do that? What wattage?

Thankx

James Stokes
07-03-2008, 8:56 AM
You might look at the Kern lasers. The say they can cut metal with a 100 watt laser. (I can not.) But They really recomend the 400 watt.

Rodne Gold
07-03-2008, 9:18 AM
We got quotes on decent metal cutting lasers , up to 3mm stainless , and they were all round 160-200K mark. 500w+

Derek Kern
07-03-2008, 4:22 PM
Michael-

A 150 watt laser will cut 1/16" mild steel and stainless steel.

Darren Null
07-03-2008, 5:55 PM
You might also want to look at water cutters if it's only cutting metal you're wanting. I've not researched the pricing, but I'm pretty confident that you can get a decent rig for less than $160k

Gary Sheriff
07-03-2008, 6:47 PM
Michael,
Yes, A 150 watt Coherent CO2 laser is where you would start. This would be slow, but you could do it up to a limited thickness. Higher power is better. Coherent tubes have higher peak powers and is the reason why you can attempt metal cutting at low wattages such as 150. Machine mechanics are also very important. Flatbed systems are typically flying optic. Metal cutting can be tricky and the larger table size you have, you could have a beam divergence become an issue. This means different focus points along the table.

You need to cut metal with a short focal point (small focused lens) for higher energy. This means that the laser head will be very close to the metal. If the metal warps due to laser heat then you run the risk of metal hitting the head. I am not saying this won;t work, but just some precautions.

There are laser systems out there that are specific to metal cutting. These typically have a fixed beam and the table (part) moves underneath or the head can be mounted using an articulating arm. The beam path is fixed but the head still moves across the entire table. Estimates for a true metal cutting laser can be north or 200k. A used system you can pay under this amount.

Then you also have YAG and fiber laser systems. These are not marking lasers. The YAG would be a pulsed YAG such as from Lasag or Rofin, etc. and the fiber laser would be a CW (continuous wave) starting with 50 watts 100 watts, etc.

All lasers Pulsed YAG, fiber and higher power CO2 will work, especially for 1/16", but be prepared to pay.

- Gary

Mike Mackenzie
07-03-2008, 7:48 PM
You could also look into Plasma cutters they are very good at this task and can be had in the 35,000 + range.

Multi Cam sells one and there are several others out there as well.

Derek Kern
07-03-2008, 9:46 PM
Michael,
Flatbed systems are typically flying optic. Metal cutting can be tricky and the larger table size you have, you could have a beam divergence become an issue. This means different focus points along the table.

You need to cut metal with a short focal point (small focused lens) for higher energy. This means that the laser head will be very close to the metal. If the metal warps due to laser heat then you run the risk of metal hitting the head. I am not saying this won;t work, but just some precautions.

- Gary

Good points Gary, I would not even consider a flying optics table for a strictly metal cutting application. Most systems that have a laser mounted on the x axis can travel at fast enough speeds to cut even thinner metals at full speed and you will not have to worry about beam consistency.

A good metal cutting system will also have a automatic z-axis that will adjust the laser focus when the metal is warped or has discrepancies.

Also know that you will have to use a oxygen assist so be prepared to keep oxygen tanks in stock. I have oxygen consumption charts for different size nozzles. PM me your email if you would like to see it.

Rodne Gold
07-04-2008, 5:31 AM
We were looking at machines from Beam Dynamics
www.beamdynamics.com (http://www.beamdynamics.com) , started out at 195k.......
Argh
Was cheaper to subcontract to existing laser cutters , their price including the metal was far below what we woulda had to charge to amortise our machine.

Sam Gardner
07-04-2008, 9:01 AM
I was particularly impressed with the specs on the Laser Photonics fiber laser (SBM1200FL) which can go up to 5000 watts!. No flying optics, 4'x4' bed and gas assist, can easily cut stainless. No idea of price but is is THE machine I would like to give a run! Guess it could outperform the BEam Dynamics system??

Gary Sheriff
07-04-2008, 12:21 PM
I also saw the Laser Photonics machine. There are a small limited number of companies that actually produce a "fiber laser". Laser Photonics purchases the 5000 watt laser and attaches it to their mechanics.

At low powers, lets say 200 watts or so, is competitive to rivaling laser technologies for cutting thin metals. It is higher power that has always been the challenge to stay competitive for a fiber laser. Watt for watt, a CO2 laser has been cheaper to operate. I would like to know the price of the Laser Photonics system also. Perhaps pricing has come down enough to rival CO2?

A CO2 at 5000 watts is very common and can cut up to about 1" thick steels. Not so much with aluminum or Titanium since those materials are much tougher to cut. (Aluminum is a heat sink). It would be interesting to find the capabilities of a fiber laser at 5000 watts. I would have thought perhaps a fiber at 2500 watts or so would be similar to that of a 5000 watt CO2 laser. This is all pretty new stuff and seems that fiber lasers may be getting more competitive at the high end.

- Gary

Kim Vellore
07-04-2008, 12:40 PM
You must also get a sample part cut, depending on the type of gas assist, power and type of material the edges of the cut could be rough . The sample I got cut once almost had a edge like a hacksaw cut part. The price was out of my range so I did not research much further, but always curious to know more.
Kim