laser tubes of different power

[Mladen Pavic]

Is it possible for any Chinese laser engraving machine model (EXLAS, HXlaser, WKlaser ...) to have two laser tubes of different power, in order to exchange them according to the engraving or cutting need (e.g. 60W for engraving stamps, and 150W for cutting 20mm thick acrylic..)?

[Dan Hintz]

Have you ever tried to source a 150W tube? I think you'll have trouble finding one... but if you did, you would need the power supply to be beefy enough to handle the larger tube.

[Michael Hunter]

When I was looking to buy my machine, I was offered a "120 Watt" ULS. In fact, the ULS had two 60W laser tubes which could be used singly or in tandem. I have no idea how they combine the beams in this machine, but if you could find out, it might be a way of meeting your requirements.

Simply swapping tubes would probably be a pain because of alignment issues.

[Dan Hintz]

Michael,

I'm not aware of any Chinese systems that offer beam combining (though that's not to say they don't exist)... beam alignment is already a bear, and I would want to futz with it on a machine that wasn't specifically designed for it from the beginning.

[Rodne Gold]

Why do you need interchangeable tubes?
Why not just get a higher powered machine and use less power for the jobs that dont require full power - we all do that.

[Michael Hunter]

Dan - I wasn't suggesting that the Chinese made dual laser machines, but that the major headache of copying the ULS idea would be better than the big headache of realigning every time the tube was changed over.


I can only think of one job that I do where "too much" power would be a problem (kiss-cutting thin label stock at 19% speed* and 1% power).
Presumably even the cheap Chinese machines have some sort of power control?

* (Epilog apparently vectors curves more accurately at speeds below 20%, by using a different alorythm).

[Rob Bosworth]

We were up in Somerset, WI. at Preeco Laser a couple of months ago. They had one laser machine that had two laser tubes on it. One came in from one side of the machine. The other came from the other side. We asked why? They said because the water cooled glass tubed lasers failed so quickly, that all you had to do was change which tube was being used, while replacing the failed tube. I did not find that to be a hardy endorsement of the lasers they were using.

[Rodne Gold]

Rob , the quoted lifespan of the glass tubes (120w) to me was 800 hrs and the replacement cost was $150 or so - if you halve it and x2 (400 hrs and $300) you get to about 75c an hour for tube replacement cost
Im not sure how that compares to sealed Co2 tubes , we have never got MORE than 2.5 yrs of operation of a tube either coherent or synrad and the average replacement cost of a 30w tube is $3000 - we work aprox 6 hrs a day over 200 days a yr - ie 3000 hrs tube life which equates to $1 an hour. If we had a 120w tube sealed co2 laser , that would be APPRECIABLY more , tho it might last longer than 3000 hrs. If however we had no warrantees on our sealed beam tubes , that hourly rate might go up 2 - 3x - regardless of what tubes we have used , we have had between 1 and 2 replacements per machine in the 18-24 month warrantee periods we get.
Not too sure whether the mainstream tubes are all that cost effective , albeit beam quality seems better than glass from what I have seen.
Not to hijack this thread , but the next laser I get will almost certainly be something like a 120w 1200 x 900 chinese machine at $5-6k as the capital cost is hugely lower than a mainstream equivalent and these can basically be dumped or scavenged for parts after a yr or 2 of operation.
Obviously the bigger bed sizes and higher power would allow more thruput than my 30w machines , making em inherently more profitable (assuming I was doing a lot of higher power requirement jobs , which of course would be the prime reason for buying such a machine)