Hi All! First post here after buying a few lasers from aliexpress sellers and I have been trying my best to cut things that the sellers claims to be able …there are also u tube videos showing 5mm ply being cut with a 10 watt optical power laser . They say its 80watt effective power yet the 12 v a 3.1 amps does not even equate to 80 watts . Perhaps I have a lot to learn but I do know my electronic basic theory having worked in it all my life.
Does anybody else find the same disappointment ?
Not anymore 
Although e.g. diode laser has become much more powerful with the combined laser systems, a thermology is still used which is often unrealistic. As you write yourself, how can 12V and 3.5A give 80 Watt? A similar problem also applies to CO2 laser tubes, here the correct output power is often not used either. This also applies to process speeds that are specified for many machines.
Like everything else on the web, you always have to pay close attention to what sounds right and what doesn’t.
The best information I have found to be able to buy the “best” laser is here in the forum. Experiences and good advice from serious people are always the best help in my opinion.
Hi.
Even though PT. Barnum put it into words quite a while ago, and one would assume we’d learn by now, the sellers of any kind of thingamajingies try their darnest to fool us into believing in their claims and false advertising.
And every once and a while they do succeed ;).
That’s where communities and forums like this one here, really prove their value.
With a little bit of searching and reading, one can quite quickly determine which claims most likely do have merit, and which ones most likely do not.
Unfortunately for the consumer, the power doesn’t come cheap, just as it was in audio amplification a few decades ago.
So there’s a “fixed” € (or apllicable currency)/W ratio that can be expected, and if the deal seems to be too good to be true, it usually is.
That obviously doesn’t prevent the sellers from asking an inflated price for an inferior product, so we still have to be alert when making purchases.
On products like laser machines, there’s an additional headache for the mechanics, that also has to perform well for the product to be useful and good value for money.
Even though the apparatus in question may not perform in reality as claimed, usually those still do perform at least 50% of the claims.
“Glass half empty/Glass half full” kind of a situation if You ask me ;).
Regards.
Sam
What they are trying to compare is the power density at the focus point.
So, if my 50W has a 0.1mm focus, then at a smaller focus of 0.05mm it’s twice as much energy (power density) or equal to 100W comparably … nice way to sell stuff… also it’s more than twice the power, at least mathematically, I’m told…
If we have more power out than in, it leads us to question why can we do this to generate perpetual power… 
These diodes dots are not that much smaller than I can get from my CO2 and are usually rectangular, not square or round.
I can get around a 0.05mm dot from a compound lens on the CO2 machine. This is smaller than most diodes.
Fiber works as a pulse laser, not continuous wave (cw) like most of these we’re used to.
I have a MP-60 with a 60W fiber jpt source. The output of this is incredible… during the pulse… This is from the jpt source manual. Around 18kW thought a fiber smaller than a human hair…
They twist the numbers… so you have to find out what numbers they are using…
I think they like the saying trust me, why would I lie?…
They often give the input power (which is useful only for circuit load) Has little to nothing to do with the actual laser power.
Most items you purchase, give you input power… Such as your electric range and light bulbs. Along with the air conditioning/heat. The AC/Heat usually will give you BTU numbers that are output values…
With lasers and motors it’s usually output for a desired measurement.
For a replacement, you really need both…
The same claim, 40W laser, my co2 is really 40W, but they use the same term with led lasers. Not telling you what the 40W represents…
Such is life… Doubt it will change in the remaining part of my life.
To misquote Zappa:
Would I lie to you to get into your wallet?