Specifically, what's the difference in 60, 80 and 100 watts - chinese laser machine

[Wilbur Harris]

I know that I can cut thicker stuff with more power but need a laser that will engrave quite a bit more than cut. I've read for a couple of days and can't seem to determine what power to shoot for. Would you folks give me some pertinent info as to what I can expect given the different powers. I was about to pull the trigger on a 100 watt machine and realized that more power may affect the engraving function. I think I've said enough such that you understand the torment...and my possible misunderstanding. I've used a 60W machine and while it really did just fine, I found myself wanting to cut thicker stuff. Well...y'all know what I'm asking so I'll hush and listen.

[Kev Williams]

When I bought my Triumph, my 3 main options were 80w, 100w, and 130w. My thinking was, I'm doing a lot of Cermark on SS, and in my 40w LS900 it's pretty slow going, so 130w should pick up the speed dramatically. But, the vast majority of my laser use is raster engraving, I don't do much cutting at all. And, since buying the thing was basically an experiment, I went with the 80w.

I'm very glad I did, because this glass tube 80w laser will cut the same items 4x as fast as the 40w Synrad laser in my LS900. And even at 80w it's hard to get the power LOW enough to be suitable. One of the 'restrictions' of most Chinese lasers is the max raster speed- Mine was factory set at 500mm/second. I found I can override that in the system parameters, and I've tested it at 800mm/sec with no problem, and I've run it several hours straight a few times at 700mm/sec with no issues at all. But even 800mm per second is less than half the speed of my LS900, and IT'S only about 60% as fast as a Trotec speedy. What it all means is, the machine can't go fast enough to make use of the 80 watts! And ironically, the one thing I can't get this machine to do to suit me is laser Cermark onto SS, which was the main reason I bought it! But it Cermarks aluminum beautifully, which my LS900 can't do at all.

Sorry for the novel-- But my advice is, if you're going to do mostly raster work, go with 80w. I've gotten mine to cut thru 3/4" maple in one pass with a 4" lens, so it's no wimp. if you're going to be splitting rastering and cutting around 50/50, 100w would probably be okay for all but 'delicate' rastering. I would only consider a 130w laser if I was going to do mostly cutting, or deep wood engraving...

[Kevin Gregerson]

From a little of my experience and the experience of others who sold in this market, glass tubes in the above 100w market tend to be overrated. Where the metal ones that say 150 will output 150-170w the glass ones tend to be 110-130 watts. We tried to figure it out. But, the best we can guess is that it's inherent issues with glass tube design that causes it and prevents it from getting the theoretical max capability of the laser tube.

Also from a cutting perspective with glass tubes their continuous beam tends to provide excellent cutting results on several materials.

[Dave Sheldrake]

glass tubes in the above 100w market tend to be overrated.

GSI / Coherant / SLC tubes all tend to punch above weight. Glass tubes have a design power, a running power and a strike power. Much of the problem isn't the tube it's vendors selling tubes at their maximum rating and not their agreed power. For example the ZX1850 from Beijing EFR is rated at 150 watts, it's maximum power is 180 - 185 watts so some dealers sell them as 180 watt tubes when in fact they are 150's. The ZX2050 is a 180 watt agreed with a rated maximum of 200 - 220 watts but is circa 200mm longer.
RF have no strike spikes so do not pump above power (high strike) for any describable length of time hence they often meet the sold rating.

Also from a cutting perspective with glass tubes their continuous beam tends to provide excellent cutting results on several materials.

Continuous Wave? unless mode-locked so are RF tubes..CW is defined by the average power over a given N period. The fact the laser may switch on and off in that N period isn't what defines Continuous Wave operation.

cheers

Dave

[Ross Moshinsky]

My general opinion is not to buy a Chinese machine if you're looking to engrave. Average western machine = 80ips. Chinese = 20-25ips. So when I run 30% speed on my laser it's basically 100% speed for you. I hate running at 30% speed. On straight text, it's almost okay but logos it's pretty darn slow.

[Wilbur Harris]

OK, can I buy a Chinese machine with a 100W power supply and then install an 80W or less tube?

[Dave Sheldrake]

Voltage will be too high, the electrodes will errode in the tube quite quickly.

cheers

Dave

[Wilbur Harris]

Darn it! It's always something....

[Kevin Gregerson]

GSI / Coherant / SLC tubes all tend to punch above weight. Glass tubes have a design power, a running power and a strike power. Much of the problem isn't the tube it's vendors selling tubes at their maximum rating and not their agreed power. For example the ZX1850 from Beijing EFR is rated at 150 watts, it's maximum power is 180 - 185 watts so some dealers sell them as 180 watt tubes when in fact they are 150's. The ZX2050 is a 180 watt agreed with a rated maximum of 200 - 220 watts but is circa 200mm longer.
RF have no strike spikes so do not pump above power (high strike) for any describable length of time hence they often meet the sold rating.



Continuous Wave? unless mode-locked so are RF tubes..CW is defined by the average power over a given N period. The fact the laser may switch on and off in that N period isn't what defines Continuous Wave operation.

cheers

Dave

Awe, thanks for the explanation.

[Vicki Rivrud]

Yupp! It's always something . . . . I think Kev is telling you the same things I have been .. . . you have to decide first, what you want the laser for

[David Somers]

Kev,

I am curious. If you were buying a 130W laser primarily for deep wood engraving would a CNC have been a better bet?

Dave

[Wilbur Harris]

OK, two more questions....

What exactly would I be losing going with 100W instead of 80W? I'm pretty clear about the ability to cut but would like to know just what I would lose going with a more powerful tube.

What will I lose if I buy a BIG laser (sizewise)? I've got enough space in this kitchen for quite a large laser...and bigger doesn't seem to cost a whole bunch more. It would seem there's a trade off as other folks likely have as much space as I do and continue to buy the relatively smaller lasers.

[Dave Sheldrake]

Cost of replacement tubes, overall running cost (plug efficiency), the differences between 80 and 100 watt rarely justify the much higer price of the bigger tube. 80 to 130 or 150 has benefits for cutting but not for engraving.

cheers

Dave

[Scott Shepherd]

Dave, don't you sacrifice the lower end, the higher in wattage you go? Don't the glass tube machines drop off at like 10% of power, meaning you'll lose the low end of the range? The higher the wattage, the larger that number will be where it drops off?

That's a question, not a statement.

[Dan Hintz]

That's a question, not a statement.

Consider it a statement...

DC-excited tubes have a low end right from the get-go, regardless of wattage (for all intents and purposes)... let's call it 5% and under is not going to happen. Things are twitchy up to around 7-8%, then lasing becomes relatively stable. But 8% of a 120W system is twice as big as a 60W system, so those delicate substrates are going to get blown away.