[Miron.Costin]

Dear friends ,

I have a 150 watts CO2 laser cutting machine,

Searching the youtube I found out that other LAser owners 150 watts can cut from 0.1 to 1.5(2mm) steel sheets ,

I tried using Oxigen but i can;t cut it as I saw over the youtube .

Could it be the focal lens ? I use a 20 mm diameter with 63.5 mm focal lengh .

could it be a higher lens with a bigger focal lens .

I look forward to recive your opinions .

regards,

Costin.

[grawley]

Hello Costin,

Often times, under-rated mirrors are mounted on 150 watt glass tube laser machines and these drain significant power. These mirrors absorb more than 3% of the laser power and by the time that you go through several mirrors, then your laser power has dropped significantly. The same is true for the cutting lens.

Is the laser tube and/or machine new? If not, how long have you had it? The reason is that many 150 watt lasers are not 150 watts and are 130 watt lasers with power supplies that have the current increased in order to get a power output close to 150 watts (I had this experience). The problem is that the gas in the tube will be consumed quickly and the laser will need to be replaced.

Try using a CO2 laser power probe to measure the laser output power before and after each mirror. This should shed a lot of light on your issue. I sell this laser power probe and it can be found on eBay, Amazon, and in the classified section of CNCzone.

[Gweikelasers]

Hi, Costin,

We have some machines similar.

For cutting metal, not only 150W is enough.
1. It needs to have the auto-height addjustment for metal.
2. 63.5 focus len is OK
3. servo and ballscrew to raise the machine cutting ability
4. knives bars below should be very sharp, otherwise it will reflect the laser
5. tube must be good, has very good laser beam.

[Exsecratio]

Hi Costin,

I tried using Oxigen but i can;t cut it as I saw over the youtube .

How did you use the Oxygen? not through the basic air assist I hope?

cheers

Dave

[Miron.Costin]

Thanks Dave !

I tried several modalities among them was the basic air assist but also directly from the o2 container via a hose puted side-above 2 mm from the part.

[Miron.Costin]

Thanks for the reply unfortunetely there are some things my laser doesen;t have :

1. It needs to have the auto-height addjustment for metal. - NO autofocus-
2. 63.5 focus len is OK
3. servo and ballscrew to raise the machine cutting ability NO
4. knives bars below should be very sharp, otherwise it will reflect the laser YES
5. tube must be good, has very good laser beam. I THINIK IS GOOD I HAVE THE MACHINE TILL APRIL

[Miron.Costin]

Thanks for the reply grawley ,

Can you advice me in buying good mirrors or focal lens , one of the focal lens I use now it ;s gone a little cloudy as if i scratched it with a metal or something .

In my opinion the power from the tube is much bigger than it can practicly concentrate in the focusing spot .
The laser tube / machine were new bought them in april .

The IDEA is that my order was a laser machine at 170 watts laser power ( so it is writen in the invoice), the laser tube is long around 1.8 metters maybe longer but there is no place were is writen the power of the tube !

the tube has a label on it but at the section power : the field is empty .


Regards .

[SPC-laser]

Hi Costin

a Constant optical path devices is necessary，and use 5 america 26 lens and mirrors totally .

i think its very difficult to change a normal 150w laser machine to cut metal。there is a lot of details you need to change。

[spclaser3]

Dear,
Our company is Jinan Spc Laser Co.,ltd [ Shandong, China (Mainland )] .If you have any questions,feel free to contact me.
My email is :[email protected]
Alice yang .

[Exsecratio]

I tried several modalities among them was the basic air assist but also directly from the o2 container via a hose puted side-above 2 mm from the part.

really BAD idea Costin, the air system on a laser isn't rated for oxygen.

The IDEA is that my order was a laser machine at 170 watts laser power ( so it is writen in the invoice), the laser tube is long around 1.8 metters maybe longer but there is no place were is writen the power of the tube !

It's a 150 watt with a peak of 170-180 at that length.

Changing the lens and mirrors will make very little difference, (the differences between western and eastern lens mirrors are fractions of a %) to cut metal the Oxygen blast needs to be in the 30 to 80 psi range and about 1 - 2mm directly above the job.

I have to say again, adding Oxygen to a machine not intrinsicly designed for it is very much like making a huge bomb. Nothing in the machine is rated for Oxygen safety, the tubing, the wiring, blowback arrestors, extraction all have to be designed for use with Oxygen.

cheers

Dave

[tejaswood]

Dear,
Our company is Jinan Spc Laser Co.,ltd [ Shandong, China (Mainland )] .If you have any questions,feel free to contact me.
My email is :[email protected]
Alice yang .

Are you offering support or just trying to sell your machines?

[grawley]

Thanks for the reply grawley ,


Can you advice me in buying good mirrors or focal lens , one of the focal lens I use now it ;s gone a little cloudy as if i scratched it with a metal or something .


In my opinion the power from the tube is much bigger than it can practicly concentrate in the focusing spot .
The laser tube / machine were new bought them in april .


The IDEA is that my order was a laser machine at 170 watts laser power ( so it is writen in the invoice), the laser tube is long around 1.8 metters maybe longer but there is no place were is writen the power of the tube !


the tube has a label on it but at the section power : the field is empty .




Regards .

Hello Costin,


A few items related to posts here.
1. In my experience, autofocus is not needed unless you are laser cutting large sheets or sheet of metal that you are unable to keep flat. There are different, and much lower cost technologies to hold a sheet flat. You can use clamps, weights, and magnets, or make it flat before putting it on the laser table. The automatic focus is a preferred method, but quite costly. I put a Synard 200 watt on a Chinese machine sized 1200 x 900 for a customer doing sheet metal artwork. He did not use an autofocus.


2. Servo motors combined with ballscrew drives are more accurate than belt drives combined with steppter motors and they are more costly. It is not necessary have a ball-screw motion drive for metal cutting. I put a Synrad 200 watt on a Chinese 1200 x 900 standard table with stepper motors and a belt drive and it cut metal fine. One of the reasons that Chinese companies recommend ball screws is because they mount the laser on the gantry. With the increased weight, the belt drive can be problematic--for example, their typical light-weight belts will stretch, and therefore you have a loss in accuracy.


3. A few months ago, I received Chinese mirrors and tested a glass tube 150 watt laser from Beijing EFR. The mirrors and the focus lens all absorbed much too much power and there were significant losses by the time the laser hit the material. In addition, many of my brand new (less than 3 month old) Chinese mirrors that were stored in my shop cabinet had corroded. I asked my supplier and there was no explanation. I sent them back for review more than a month ago and have not heard anything.


I have USA made high quality mirrors that are sized one inch in diameter and can sell them to you for USD40 each, and put them on eBay for you to buy.


4. The focus lens is important and getting the right one most important. Most laser machinery buyers simply understand that the focus lens material is ZnSe or Zinc Selenide. Chinese ZnSe is generally much lower quality than the USA brands that are made in Singapore and developed countries.


In general, in my experience, most buyers and assemblers of the laser machines are unaware of these problems, do not measure laser output power, and move machines at the lowest price acceptable to the buyer. One of the benefits of CNCzone is that it makes buyers more aware of the issues and able to make more informed decisions. The 130 watt, 150, 180, and 200 watt power range are most impacted by these issues.


I can sell you a focus lens for $90 and will put it up on eBay if you are interested.


Shipping will be at cost by FedEx.


5. Before you do all this, my recommendation is that you measure your power supply current to determine if the power supply has the proper current. Often times, unscrupulous suppliers increase the power supply current to show higher power at the CO2 laser when delivered. This causes the laser tube to loose power quickly, within a few months.


Here is a link to instructions that I created, along with a lot of photos, that will guide you through the process. You need to be very careful to take the necessary safety precautions.


http://tinyurl.com/lqs2wgr


If the current is set above 28-30 mA, then I recommend testing the laser output power.

[grawley]

Thanks Dave !

I tried several modalities among them was the basic air assist but also directly from the o2 container via a hose puted side-above 2 mm from the part.

A small nozzle orifice is best when using oxygen for CO2 laser metal cutting. The small nozzle hole (around 2mm in diameter) will provide an extremely high speed jet of oxygen that will assist in piercing the metal and pushing the metal downward and outward during the cutting process. In addition, the volume of oxygen consumed is greatly decreased, as compared to a typical Chinese nozzle with a very large diameter nozzle.

Attachment 200768Attachment 200770Attachment 200772

[cinematic2]

If your machine use chinese glass laser just forget about cutting any metal.
You need 200W+ of RF laser, not DC.