Doing lots of cutting & Tube life?

[Mark Ward]

In general our laser is mainly engraving rather than cutting on most jobs, it will cut around the outside but the majority of the time is spent engraving things.
We are looking at a job that will be far more cut heavy and I was wondering if loads of constant cutting will massively eat into the tubes life?
Potentially one set of small items would be a 10 hours worth of job time (quite a number of sheets of wood), with probably at least 7+ hours of it being time cutting.
I thought I'd read something that loads of cutting drastically eats into your tubes life and want to know if taking on a very constant cut heavy job would do much damage to the machine (Trotec).

[Mike Null]

Mark
I've been at this for about twenty years and can't say that I support the idea that cutting shortens tube life. It sounds logical but I've seen no evidence that supports the theory.

My own business deals with engraving and cutting laminated plastic so nearly every order I run involves cutting every piece; literally a couple thousand or more a year. My last tube, a Coherent 45 watt, lasted 8 years before requiring rebuilding. It's in its third year since and running well.

Several years back I had one order that involved cutting 5000 pieces of 1/8" cherry labels. i could not detect any harm done by that.

As far as I know there are no industry statistics that will reveal the quirks of the CO2 tube.

[Scott Shepherd]

I've never heard that. We vector cut with our machine a lot. Some weeks it runs all day, every day, just cutting, other weeks it's a combination, other weeks, mostly rastering. I'd say you are perfectly fine. We are finishing up a 160 hour job that was vector cutting only.

[Tim Bateson]

I agree, my 1st machine (Mini 35w) still works with a 11+ year old tube. Lot's of cutting, some jobs a couple hours long. Other times I cut 8-10 hours a day. I do have to give it a few minutes to cool between large jobs - fans are in hyper drive by time a large job finishes. Specifically the airline brake pads I cut. Each sheet takes nearly 45 minutes of cutting at about 3% speed (that old Mini 35 watt).

[Brian Lamb]

Related question, I was doing some acrylic parts in 12x24 sheets, getting 70 parts per sheet. I found that my cutting would drop off as time went buy, first row of parts fell out of the plastic easily, second had to be broken out, third and fourth barely penetrated the acrylic (1/8" thick).

I managed to get through the job, about 800 pieces, by manually adjusting the speed setting and decreasing it as time went by on each sheet, that way I could get the parts cut.

Does this sound indicative of the tube failing? ULS X-600 50 watt and the tube is from 2011 according to the tag on it.

[Mike Null]

Brian
That's the way my first laser, a ULS, behaved when the tube went out. Once it began the decline was fairly rapid.

[Brian Lamb]

Thanks Mike, looks like I'll try out Evergreen, although I think they call themselves something else now...

[Kev Williams]

I am of the opinion that RF tube life is directly proportional to it's "on" time. Like light bulbs. How much 'on time at full power' vs partial power comes into play, no clue, but probably not all that much. Regardless, 'on time' explains, for me anyway, why my 13 year old LS900 hasn't lost a step, and neither has Gary's now 12 year old GCC I've been using for nearly 2 years. I don't know how much cutting Gary did, but I'm assuming that like me, he used it more for engraving than cutting. I read on these pages that many have had to recharge or change their tubes in shorter periods of time, and it also seems that many of these machines did a fair amount of cutting.

Cutting involves long stretches of on-time, engraving not so much. Is my theory correct? Have no clue other than what I gather from reading others experiences, and that my machines just keep going (knock on my head)...

As to the question at hand, I do not believe cutting 'drastically' changes tube life. Just somewhat, due to time use. And it the grand scheme of laser things, a 17 hour run time job is pretty insignificant

[Tim Bateson]

...a 17 hour run time job is pretty insignificant

That's at least $1,700 per run, but due to ware & tear of such a long run probably at least $3,400 per run. Good money, but potently hard on the equipment.

[Gary Hair]

If you are pricing your jobs correctly then it won't matter how soon your tube fails. That 10 hour job should be netting you something around $2,400. How many of them do you need to pay for a new/recharged tube? Not many.

[Scott Shepherd]

Good money, but potently hard on the equipment.

Hard on the equipment? I hope not. Like I mentioned above, we're finishing up a 160 hour job of nothing but vector on one laser, and have been vectoring on our other laser all day yesterday and today. Both have tubes that are about 8 years old and have been running like this for years.

If you are pricing your jobs correctly then it won't matter how soon your tube fails. That 10 hour job should be netting you something around $2,400. How many of them do you need to pay for a new/recharged tube? Not many.

$240 per hour is your standard rate Gary? That's pretty steep for vector cutting.

[mitch stephens]

Related question, I was doing some acrylic parts in 12x24 sheets, getting 70 parts per sheet. I found that my cutting would drop off as time went buy, first row of parts fell out of the plastic easily, second had to be broken out, third and fourth barely penetrated the acrylic (1/8" thick).

I managed to get through the job, about 800 pieces, by manually adjusting the speed setting and decreasing it as time went by on each sheet, that way I could get the parts cut.

Does this sound indicative of the tube failing? ULS X-600 50 watt and the tube is from 2011 according to the tag on it.

Next time try starting at the side that you are having trouble with and work your way back to where you used to start. Your mirrors could be out of alignment from one side to the other
Mitch

[Gary Hair]

$240 per hour is your standard rate Gary? That's pretty steep for vector cutting.

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.

[Brian Lamb]

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.

Next time try starting at the side that you are having trouble with and work your way back to where you used to start. Your mirrors could be out of alignment from one side to the other
Mitch

[Rich Harman]

I found that my cutting would drop off as time went buy, first row of parts fell out of the plastic easily, second had to be broken out, third and fourth barely penetrated the acrylic (1/8" thick).

Check the distance from the laser head to the workpiece where it cuts best and where it cuts worst and see if there is any variation.