Instructables
PLEASE NOTE: I'm really not competing to win the laser, a t-shirt would be fine, thanks.
I saw the competition and thought it would be fun to show off my system.

INTRODUCTION. The general idea of this CO2 laser system is that a beam is directed down to a part for cutting. The part sits on a computer controlled platform which moves the piece around the stationary laser beam. Cutting is acheived by passing the beam through a focusing lens. A focused beam exits through the bottom of a cutting head nozzle. Gas, such as oxygen, is fed into the side of the chamber below the focusing lens. This gas exits the nozzle along with the beam and the laser beam/oxygen combination serves to vaporize the steel for cutting.

Click here to see it cut

One thing that I discovered when making this system is that purchasing the laser was the easy part; many other systems are required to be on-line in order to achieve anything useful with the laser. To give you an idea, this is a comprehensive diagram describing the basic components of a CNC laser cutting system.

This is a picture organizing many of these components around the central control unit and includes other sub components such as the motors, encoders, solenoids and flow sensors.

Assume for now that you have a really great laser, and these main components are handled:

  • Laser head and power supply
  • Optics
  • Control unit
  • CNC table and power supply.
  • Computer
  • Cooling systems

What other systems have to be on-line in order to have a cutting operation?

Electrical
Two 110VAC 20 amp lines were run to operate ancillary equipment, a 220VAC 20 amp line services the laser power supply, a 220VAC 20 amp line services the chiller outside of my house, and another 110VAC 15 amp line runs room lighting.

It was also useful to make boxes like this that have 110VAC entering into them and also had relays system that could be driven by TTL levels to run various appliances like ventilation.

Ventilation
A ventilation system has yet to be installed in the work area. This will be required to remove fumes and reduce smoke that will contaiminate the optics inside the beam delivery system. The laser has the capability to cut a number of different materials like wood and plastic. Ventilation will be essential to remove the fumes produced by these materials.

Gas Lines
The laser cutting system can use either oxygen or nitrogen depending on the cutting application. This required that a couple tanks get installed and I ended up mounting the tanks up off the wall. This is to conserve floor space so I can cut larger sheets of metal. The brackets came from the welding supplier. The plastic chameleon has a couple magnets embedded in it for sticking to the tank.

Here's a pic of the gas set up. Here is another.

Support Arm
The laser head needs to be suspended about 48 inches away from the nearest wall. Another design criteria was that it has to be able to change the height of the laser along the z-axis. A CAD drawing was put together, and I bought a pile of channel iron, angle iron, and flat stock then went to work with my chopsaw. Note the lag bolts attaching the angle iron to wall and floor.

Here's the support.

 
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AaronM116 days ago

Well written and creative project.great possibility to show your projects and thoughts in fast and hassle-free way. I really like your post with all cutting operation.Thanks for sharing.

http://goo.gl/IYyn4C

pleabargain4 years ago
I believe the link to "this is a comprehensive diagram" is broken.
where is the laser tube ?
ok, here comes a stupid question., -Why can't you just laser cut by hand-?
The machine would be much more accurate. Besides, how would you wield a 250 Watt Laser with 2500 Watt water coolant?
what if you had it mounted like this but with no motors and used like a bandsaw
I agree, Thanks.
Congratulations, it's a great work and perseverance sample. I would like a CNC of those at home.
This is very cool. The kerf on my machine is 1/8" running a CNC plasma torch. What is the kerf (width of cut) with your laser here?
dirceu2 years ago
the secret pro metal cutting laser 150W co2?
are the mirrors, lens, polarizer cut quality enhancer, or the collimator, or the laser tube?
hbk19662 years ago
Just a little bigger then we will need it in the military.
Psssssh Ahhhh wheres my wing!!!
corradini2 years ago
Link near top - "comprehensive diagram" - is 404 Not Found... :-(

Great project - been thinking about building such a thing (after finding out that TechShop here in the Bay Area doesn't have a metal-capable laser cutter... :-(

(Hint, hint, Jim, Ridge, et al... >;-)
FrozenFire3 years ago
Lovely project - but expensive.
And it doesn't have to be.
Less than $350 can get you 3 axes *with* controlling electronics and motors.
(see the reprap project for a great example, although with a moving head. a moving table is just as easy and maybe even cheaper though.)
You don't even need 3, but if you use 3 you could save on laser power and thus on laser cost a lot by using a reciprocating laser setup which adjusts focus during the cut.
A quick look on ebay gives me $1375 (that's with worldwide shipping) for a laser with power supply included.
Your transformer setup requires a large, bulky, line frequency transformer which gives you horrible regulation and high cost. A computer power supply or some other form of SMPS will give you much better regulation at a lower cost. The $350 figure already includes the power supply with the electronics though.
Cooling with a cheap pump and water is fine, so I'll say $100.
I have no clue about optics though, but the optics can't cost a lot more than the laser so I'm making that $1000.

laser: $6500 - $1375
CNC table: $ 500 - $ 350
Optics: $2500 - $1000
Cooling: $ 500 - $ 100
electronics:$5000 - $ 0 (driving electronics included in table price)
total: $15000 - $2825

Savings: $12 175

Or, if I am wrong about the optics and it's indeed $2500, the total is still only $4 325. Savings $10 675.
I hope this is of use to someone =)

I just realised that the $350 table might be a bit unrealistic for a laser cutter cutting steel sheets - but even a $1000 table still means significant savings.

Just my $10k ;)

--Nathan
Hi,

Do you have any sources to buy Laser Head, Optics..?

Thanks
Yatish
Hi,I am Praful here.I am setting up Laser cutting with Coherent 400W especially for sheet metal.Can you please let me know who can support me for laser head,optics etc.I found 1 laser head frm precitech but its too expensive (20k-Euro).Can you pl give me some inputs rgd this.
saeedaaza2 years ago
dear sir
I want to build a cnc laser for cutting stanless steel 6 mm
so I need electrical parts . like power suply400w- laser gun-and ets
if it is possible for you send me comlete lists of parts and price I.ll need to
building these machine.

best regards
ToLiCo2 years ago
Really neat and creavtive. Another options, a plasma cutter to save much more money.
Valadares3 years ago
I think mr owhite made a mistake the energy density while making the calculations
the correct correct is 0.1643 watts/mm2 .
Pkranger883 years ago
You might update your 'ible with the embedded pics. Apparently the links are dead.
xxx833 years ago
really very nice, great job
dude that is sick awesome!! but way to expensive. its gonna take me forever to gather that much money.
Tommio696 years ago
I have a 5KW CO2 laser- when cutting stainless use Nitrogen (99.5% pure) and you'll have clean shiney edges on your steel :), also do you where any eye protection?! I really hope you do, as CO2 lasers emit radition that burns away your eyes lens without you feeling it.
what kind of eye protection do you recommend, would regular safety glasses/sunglasses work or would you need smoething stronger
Regular goggles won't do anything for the laser frequency... you need goggles that are designed just for that purpose... start here...

http://cascadelaser.com/safetyeyewear.html

Jerry
CO2 lasers emit a 10.6 micron wave. Regular safety glasses will work fine.
Most safety glasses filter UV. This is IR, 808nm (or 10.6micron, whatever you like).
And either way, I wouldn't bet my eyes on a cheap pair of safety glasses.
A $100 pair of laser goggles might seem expensive - until you lose your sight.
The $50 you saved won't get you back your eye.
808 nm doesn't equal 10.6 microns. That would be 10,600nm which is in the far IR band, and regular lexan blocks it effectively. A few sheets of plexglass would make an adequate enclosure.

808 nm, on the other hand is in the visible range and will pass right through anything that visible light passes through.
It is ingenuous to think protection glasses are the definitive solving panacea in protecting your eyes from hundredsW/mm² and up, reflection fluences.

It is really important to have the laser cutter inside an enclosure or to precisely study the angles of possible reflections coming out to the observer to create and set protecting panels in the correct paths.

Most people isn't aware of this and handle lasers with absolutely insufficient care.

Be aware! You have only two eyes, no spare!
is your laser a diode or a miror laser?
CO2 based laser
Thus, a "mirror" laser.
Known to most as a gas laser.
verence4 years ago
Nice I'ble, but waaaay too expensive for me... Good write-up. But how do you get from 106 watts/in² to 1550 watts/mm²? The conversion of 1in² = 645mm² is correct, but that would give 164 mW/mm2. Real world check: 100W on a square inch, that's the heat of a strong (old school, non-green ;-) ) light bulb on the area of a bigger stamp. That would be warm, even hot, but not enough to melt steel. 1550W on a square milli-metre? That would be the energy of a bathroom heater on the surface of a ball point tip (give-or-take...). Yes, that might be enough to melt metal. By the way that would mean 1,55kW*645 or about 1MW per square inch!
There's this magical thing called lenses too..
vlaskop verence3 years ago
You don't have to melt the steel in order to cut it. The laser ( or torch of say oxy-acetylene or propane-acetylene) only has to heat the surface to the point where the oxygen will start burning the steel which is well below the melting point.
The oxidized steel has a melting point of ~ 1450 C and runs off the steel which melts at a little over 1500 C.
juampyasdf4 years ago
the last one is my favorite :D

What IS the last one anyway?
I believe he/she is referring to the "Items I've Made" section with the last photo being his finger cut by the laser...
jhd043 years ago
Yes, I would have to agree with others. Very, very nice job on the device, but put a metal box around it when it's in use. Cheap insurance against instant blindness...
Win7Maniac3 years ago
I think most of the media links on the intro page are broken...
Shame, the video is missing.

Great blog though, many thanks, Andy
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