[Laser Doctor]

Well, if you actually lase for 8 hours a day, your hours are basically correct. Try measuring actiual lasing time. Time on only. You may only turn the laser on 4 hours in your 8 hour day. 210 days a year is hard pressed for days worked. So, you would be looking at approximately 840 hours of use. Like I mentioned, RF lasers last up to 20K hours. Yes, there is a larger expense in the purchase. Production companies, not hobbyists require these requirements. You are also correct for using less current. When you use less current the laser gas doesn't disassociate as quickly. The atomic O3 and O4 oxygen created is less than when driving the current through the gas harder. This is why a proper mixture of gas, along with the use of gold, can make a glass tube last around the 1000 hour range when the conditions are just right. Cooling is also that important. The cooler you keep the laser tube (no lower than 60 F) will also support longevity.

Good Question the Laser Doctor.

[Laser Doctor]

Unfortunately I need to keep my background "Super Secret" . As time progress, you will see I 'm well qualified to answer your laser questions. I certainly have a rich background in all laser wavelengths. I'm a little short on Eximer and Diode lasers but will try to answer those questions. I have been in the laser field since 1978, going to college and graduating in the field of lasers and electronics.

[Laser Doctor]

Hi Laser Doctor,

I've got a question regarding optimum laser power for doing both cutting & engraving. Reading around on this forum and others, some have mentioned about 80watts being about the max for engraving purposes. I'd like to be able to do fairly fast cuts in 1/4" material, with the capability of 1/2" acrylic, while still being able to doing quality engraving. Is there an optimum power for this? 60w? 80w? I'd be looking at non-RF lasers, most likely Reci tubes.

I always say more power, more speed. The higher the power the greater cutting depth and less time to perform the task. Cutting depth is dependent upon a few things. Consider beam diameter and the length of you focal cutting lens. The shorter the lens focal distance the smaller the spot size, thus the higher power density and the greater depth cut. Small laser beams produced by the RF laser will always be more efficient than a glass laser tube. This is why they make such great cutters and engravers. Research laser power density, formulas are available to tell you how many actually watts of cutting power will be produced, depending upon the laser type you use. I could give you the formula but that would be to easy.

[Laser Doctor]

The Laser Doctor will see you Monday. Same laser time, same laser channel!

[atv2]

Are you sure about the 20k hours? Assuming Walt's lasing time is typical, 20k hours is over 19 years. Most people don't seem to get that many years of service out of thru rf lasers.

[Laser Doctor]

Good morning the Laser Doctor is in. Yes, I am sure of the number. This figure is well document for some manufactures RF lasers. I can also assure you, that this number is not realized what so ever for manufactures like Epilog, Universal, Trotec, Coherent lasers installed in engraving systems. THis # of hours is more relative to Industrial laser tubes. These tubes hold much larger volumes of gas, thus longer hours.

[asuratman]

Laser Doctor,
Where to get RF laser good and cheap? Can we replace CO2 laser tube in the machine with RF laser directly?

[Laser Doctor]

Try Ebay

[herby08]

hi laser doctor
you are right in priciple for people who just laser ocasinally but in my case the laser works 8 hr 6 days a week because some of my sub 3D acrylic pieces require about 3 to 4hr and I mostly do 2 to 3 pieces a day to keep up with demand. thats the reason how I could calcualte the laser time.
I also wana say last year on one of my machine the tube was bad but I had a few just engraving jobs to do and I wana point out this tubes where I could not even cut 1/8 acrylic with 5 or more passes it still lasted about400 hr with engraving a bit off power increase but the outcome was the same as with a new tube. then I finally replaced the old tube. what I wana say is for people who just wana engrave they still can do this witha allready bad tube
but thanks greetings
walt

Well, if you actually lase for 8 hours a day, your hours are basically correct. Try measuring actiual lasing time. Time on only. You may only turn the laser on 4 hours in your 8 hour day. 210 days a year is hard pressed for days worked. So, you would be looking at approximately 840 hours of use. Like I mentioned, RF lasers last up to 20K hours. Yes, there is a larger expense in the purchase. Production companies, not hobbyists require these requirements. You are also correct for using less current. When you use less current the laser gas doesn't disassociate as quickly. The atomic O3 and O4 oxygen created is less than when driving the current through the gas harder. This is why a proper mixture of gas, along with the use of gold, can make a glass tube last around the 1000 hour range when the conditions are just right. Cooling is also that important. The cooler you keep the laser tube (no lower than 60 F) will also support longevity.

Good Question the Laser Doctor.

[asuratman]

Laser Doctor,
What is RF stand for? I tried to find RF laser tube on ebay, none. But if google co2 laser, many. So what is looklike?

[Laser Doctor]

Good Morning the Laser Doctor is in. RF stands for Radio Frequency. Companies like Synrad Lasers and Coherent Lasers are RF excited. Try looking at companies like Laser Resale or Photovac Laser Resale sites.

[asuratman]

Laser Doctor,
What is RF stand for? I tried to find RF laser tube on ebay, none. But if google co2 laser, many. So what is looklike?

[mondo50m]

This is an extremely newbie question, but I have not been able to gleen an answer to it. What is the temperature of the laser spot from a 40w laser that is cutting through 1/4" plywood at 100%? It is just a curiosity question, no real reason to have to know.

Milt

[Laser Doctor]

Sorry the Laser Doctor does not have a answer to your question. If I were to guess..mmm. the temperature would approach that of the sun.

[Rodney Gold]

The beam has no temperature at all , its only what is absorbing it's energy that heats up.
Depends on the properties of material the beam is hitting , energy density and duration of beam as to what heat can be achieved

[keebler303]

To answer that, you would have to know the laser power, spot size, emissivity of the material you are cutting at 10.6 um wavelength, specific heat and thermal conductivity of the material you are cutting, etc.

Better just to assume it is "really hot" as suggested by Laser Doctor.

Matt

[mondo50m]

Thanks all, so its really hot, like the sun.

Milt

[Laser Doctor]

The Laser Doctor is in.......

[Laser Doctor]

The Laser Doctor is leaving for the day. A very slow day for the Laser Doctor. No office calls today. See you tomorrow, same laser time, same laser channel.

[lucylucky]

:wave: