Doing lots of cutting & Tube life?

[Scott Shepherd]

I don't do much vector cutting Steve, mostly rastering which I start my calculations at about $240/hour but usually end up much higher than that. Well, except for the job I'm running right now... in 11 years I haven't underbid a job this badly, really badly! My rate for vectoring would be no less than $120 but would try to work it out to be closer to $240. I have too much work at $240++ to even think about anything less. I base all of this on the rates I charged for my 30 watt GCC, typically $120 was the minimum. Considering my 80 watt Trotec is at least twice as fast means I should charge $240 and will end up slightly higher priced than what I would have charged for the 30 watt machine.

Well Done Gary! I like quoting work on the Universal and running it on the Trotec too

Can't complain about that kind of money for sure. Wish we had more of those.

[Brian Lamb]

None, my laser bed is within was close as my eye can see on the focusing tool to being level everywhere.

[Dave Sheldrake]

Laser tubes are under the most stress during the rise cycle, On DC tubes they last about 1/3rd less time if used for engraving, on RF's it isn't such a big margin but the margin is still there (typically 5 - 8% shorter life if used for engraving only)

Same reason my PC's stay on 24/7/365 and all my chillers

[Scott Shepherd]

Laser tubes are under the most stress during the rise cycle, On DC tubes they last about 1/3rd less time if used for engraving, on RF's it isn't such a big margin but the margin is still there (typically 5 - 8% shorter life if used for engraving only)

So that is the opposite of what the OP was told! That's interesting.

[Mike Lysov]

Tried that, went side to side (rows) instead of columns, left to right, and the opposite, top to bottom and the opposite. When I first fire the laser up and it's "cool" it cuts pretty well, 20 minutes into it it's fading fast.

I had exactly the same problem with my 100W Synrad tube. It was great when it was brand new then after 3-4 years it started to behave the same way as yours. Then earlier at the end of the last year it stopped working.

I sent it to Synrad for repair and they replaced some PCBs in a RF power supply. It fixed all problems and the tube worked for about 2 months. I run it on long jobs many times after the repair and never had a problem with loosing power on a long run.
However it has another fault right now which I believe is either some bad cable(there are three of them) or a connection ports for them on the tube or the RF PS. It is a shame Synrad charges that much for repair but they have not checked all my cables and ports on both parts. I am trying to find what cable or port is bad right now but if I fail I will send it back to Synrad and ask them to repair it under warranty provided for their repair service.

[Dave Sheldrake]

So that is the opposite of what the OP was told! That's interesting.

Lasers in general like stability Scotty temperature and current pretty much equally. DC tubes especially, they fire a high ignition current at the start of each line pass and each on off cycle, in effect the tube is running at a higher than average overall run current because of that.

RF's not so much but the effect is still there to a far lesser degree.

[Wojciech Szul]

Laser tubes are under the most stress during the rise cycle, On DC tubes they last about 1/3rd less time if used for engraving

Sorry Dave, what do you mean by the "rise cycle" on DC tubes? Isn't laser action done thousands times a second - even on CO2 glass lasers (not RF)?
Andy by the way - what is better in your opinion: cut fast with bigger power or slower with lower power when visual effects of work are comparable? Regards laser tube (CO2 glass DC) persistence? (rails or our own time are separate things).

[Dave Sheldrake]

Isn't laser action done thousands times a second - even on CO2 glass lasers

It is however the gas is already in a pre-ionised state (almost nil time between fires) where as on engraving the gas is already dropping to the ground state at the end of each line

cut fast with bigger power or slower with lower power when visual effects of work are comparable?

Commercially, fast at higher power as it's more time efficient and so long as you stay within the tubes maximum operating parameters

[Wojciech Szul]

Commercially, fast at higher power as it's more time efficient and so long as you stay within the tubes maximum operating parameters

Commercially is obviuos, more interesting is what is a impact on tube. I use machine rarely, counter shows less than 40 hours of lasering last year.

[Dave Sheldrake]

Commercially is obviuos, more interesting is what is a impact on tube. I use machine rarely, counter shows less than 40 hours of lasering last year.

It may be a surprise but that is more likely to reduce tube life than running them every day for 12 hours. There is little to no effect on a tube if you run it within it's operating range compared to running it at low power.

Oxidation of the electrodes will become a problem quite quickly if a machine is run then allowed to idle for any length of time (weeks etc) Fast at high power comes with caveats, sometimes it is more efficient to run slower at lower power once you start exceeding the materials ability to absorb power