Engraver tube life expectancy - time or hours used

[Scott Naylor]

I have been reading the forum for a while and have been trying to research some of the details of owning a laser. I have a CNC router and have been thinking of adding a laser engraver to my business, but I would not be able to afford a new one at this point. So, as I am looking at used units through various sources, I have a couple of questions that maybe you - the experienced users - would be able to answer easily.

1. I read the information from Universal Laser and Epilog on tube life, but is the life expectancy strictly hours of use, or time, or both. If a machine was only used lightly (5 hours a week) but for 8 years or so for example, would it still have plenty of life to make it to 10,000 hours, or does time take its toll and it probably is overdue for replacement.
2. I have read a few things on the environment where the laser resides. How important is it for the temperature to be maintained. My shop in Ohio is cold during the winter. I can warm things up before I begin to work, but do not typically heat when I am not there.

I know there are more considerations than these above before buying a used machine, but these are couple of questions I would like to have the answer to before I continue my pursuit of a laser.

Thanks for any help you can provide.

[Scott Shepherd]

Scott, from years on this forum, my opinion is there is no way to answer the tube life question. There are people with tubes that are failing weeks or months into service and then there are stories where people have had the same tube for 8 years and still running strong and everywhere in between.

The charts and graphs I have seen from the factory on it is that about the 5-6 year mark, they start down a failure path that never recovers. Meaning, when they hit that point, they start to lose power slowly and then all of the sudden, it drops off almost completely at some point after that.

To me, that's all theory, graphs and charts. Doesn't mean too much when you're 2 months out of a 2 year tube warranty and it fails. There's just no way to predict it. It seems it's very tube specific. You can get a good one and it'll last a long time, or you can get one that's not so good and it won't last as long and there's no way to tell the difference.

I would not allow my laser to freeze or stay really cold. The tube is an all aluminum housing and which has seals that keep the gases in. Aluminum, dropping down to that level and then heating up again is going to move way more than I would be comfortable with.

It's filled with a mixture of gases that are suspended in there. It's my understanding that the gasses or molecules can begin to settle in the bottom of the tube, which means they don't get "excited" when powered up. I would think that allowing the temp to drop into freezing or even close would have some negative impact on the way those molecules are suspended and interact together.

That's just my opinion, there are folks on here with a lot more education in the specifics than I have, so I'll let them say for sure, but that's my take on it.

[Guy Hilliard]

Scott;

The life expectancy of a laser tube is not the amount of time it is used (turned on) but the elapsed time since it was manufactured. So a tube with a life expectancy of 20,000 hours is expected to output its rated power for about 2 1/4 years from the date of manufacture regardless of how much or how little it is used. It has been my experience that most tubes last more than their expected lifetime.

[donald bugansky]

Scott,

I too live in Ohio as well and it can get really cold during Dec-March. I just keep the shop at 60 degrees via radiant floor heat I had installed when I built the shop. Once the slab is heated, it stays warm for quite a bit. It really doesn't take that much to heat. When I'm in the shop, I just kick the other thermostat to 68 which controls the boiler for the "forced hot water" heat.

If you are on a slab and don't want to break up the floor, they make electric radiant floor mats I believe in 4 by 8 ft mats. You could put one of those under your laser and keep it at 60 which keep the laser constant.

Lastly, you could build a small box or mitt (which is heavily insulated) and slide it over the tube area when you're not using it and it's had some time to cool down from it's last use. This may help in mitigating the tube from getting into the freezing area.

Just some thoughts.

Bugs

[Dave Johnson29]

have been trying to research some of the details of owning a laser.

Scott,

You are going to get a lot of folk lore and opinions on this one and sorting out what is what may well be confusing. We have had this discussion on here many times as you have no doubt found in your research.

I began playing with lasers in about 1998 and I do not mean laser engravers but messing with glass lasers and building power supplies. For reasons unknown to me still, back then I elected to follow the CO2 path and I currently have two. I have one 50W glass ex-medical that I bought as surplus in about 1999 and I believe it was brand new. It is water cooled and still runs fine today but has probably had no more than 20 hours use over that time.

Some years back I was offered an old ULS 1700 with a Synrad 25W tube in it. The tube is dated 1992. Synrad have no record of it having been refilled or repaired. I have no idea how many hours use it has but when I got this machine I had to rebuild the X-axis carriage and machine up new guide rails for the X-axis. Good guess is lots of use.

Synrad state on their website 45,000 hours average use from their tube and at the last time I checked, they gave no length of time. I am retired and the laser is a hobby toy so it gets very little serious use. It has been sitting unused in the garage for more than 8 weeks. Temps have been as low as 12F and currently it is 30F in the garage. I just started it up and it fired immediately and burned a small test project perfectly.

I can't go into the esoteric ponderings about gas mixes separating etc, and it may well be possible, but I can say this Synrad tube always works first time and every time. Same for my glass one which is water cooled and I use a 50-50 mix of distilled water and anti-freeze.

So, to try and help you with the dillema and based on my very limited experience, I would suggest buying something with

1:
A Synrad tube with a not too worn appearance for the mechanicals.

2:
One of the Chinese machines that have replacement glass tubes for about 200 to 300-bucks. Search here for Rabbit lasers. James and others have quite an extensive range of experiences with them.

3:
Any other machine with some form of warranty on the tube.

I hope that helps a little.

[Joe Pelonio]

I agree that you cannot predict it, for example, in my case, with a tube sold as lasting 11,000 hours:

Tube#1 lasted just under 2 years, replaced on original factory warranty, approx 3,000 hours

Tube #2 Lasted just over 1 year, had to pay for replacement, approx 2,000 hours

Tube #3, still going strong after 4 years, approx. 4,800 hours*

* Knocking on wood when I click the "submit reply" box

[Scott Naylor]

Thanks for all the responses.

The summary on the tube life seems to be - it's a roll of the dice on longevity.

On the heat. I have a small office area that I could heat if I needed to. Since this is my weekend work, heating it all of the time does not currently make since. Even though it has been cold here in Ohio, the shop has a slab floor and is heavily insulated - so it hasn't got down below 35 in there, even when we had that 2 weeks where it was 25 and below.

Dave, your comment on Chinese units has me curious. I was not originally considering one since it seemed that replacement parts would not be timely and support could be a problem. I ran across a site with a Jamieson Laser Cutter (in Connecticut) and, even though the units are Chinese, they state they spare parts in the states. Has anyone had any experience with these units?

Thanks again for the help.

Scott

[Scott Shepherd]

I think Guy has hit it right on the head. Those large numbers are 24 hours a day, 7 days a week, running or not. There are 8,760 hours in a year. So x 2 and you're at 17,520 hours. Now, take the 40,000 number people mention, that's 4.5 years, running or not.

[Dave Johnson29]

Now, take the 40,000 number people mention, that's 4.5 years, running or not.

:) but, but, but, but my Synrad tube is dated 1992 and Synrad are the only people equipped to recharge them. In fact it is so old they told me I am on my own as they stopped supporting this model in 2002 or 2004.

The hours you quote may apply to other brands of tubes.

[Scott Shepherd]

Dave, I'd hope you'd be the first person to recognize that one sample does not make a trend. There are 100's of posts on here with people with lasers less than 5 years old that have failed. You are one of the only ones, if not THE only one that have one that old that has not failed. One example like that is far more likely to be the exception than the rule.

Also, a 1969 Mustang might run better than a 2010 Mustang, but how many 1969 Mustangs are in the junk yard or scrap now? Just because one 1969 mustang runs great, doesn't mean every single 1969 mustang built is still running great.

[Dan Hintz]

Here's my two cents, so feel free to add it to the pot, stir, and take out a buck fifty...

The numbers provided by manufacturers are estimates based upon tests in controlled settings. The first problem with this, and one you have no control over, is the word "estimate"... no two tubes are going to act/react the same, and as with all non-static items, early failures are a real possibility (though hopefully rare). The second problem, and one you have some control over, is the setting the laser is used in.

Other than extremes in temperature or voltage, the worst thing you can do to a laser is allow it to sit (used or unused) in a non temperature-controlled environment. As the temp swings, the various materials expand/contract at differing rates (particularly the seals), which leads to a loss of gas. Of course, running the laser full tilt after a night off warms things up quickly, and turning off for the night after a hard workout cools things off, leading to a similar issue.

[Darren Null]

My Synrad is dated 2002 and is also still going strong.

[Bill Cunningham]

Well, from my personal experience, a laser tube will keep working right up until it doesn't..:confused:

And, the only thing that 'really' causes cancer is Saliva.. But only if swallowed in small amounts over long periods of time..(George Carlin)

[Dave Johnson29]

I'd hope you'd be the first person to recognize that one sample does not make a trend.

Scott,

That's why I stated in my original reply "very limited experience" as this is the only Synrad tube I have ever had, but the glass ex medical is still going strong and I believe that was made by Coherent probably around 1996. Admittedly the glass one has had very little use, but it still fires first time every time. In the time I have been messing with CO2 lasers, the only failures I have had were because of me. No water flow, voltage fluctuations from the power supply.

The other point I was trying to be subtle about was that there are lots of stories about dead laser tubes less than 5 years old, but very few if any of those are Synrad tubes. I can only recall one story on this group of a Synrad early failure.

I do not like pointing the finger and damning any other products and I have nothing to do with Synrad in any way. I am just stating my experience with CO2 lasers and my old Synrad tube. Over the years I sold off the other CO2 lasers I experimented with so I have no idea if they are still working or not, but many ran for several years before I was coerced into parting with them.

[Scott Shepherd]

So who's still using Synrad tubes on their systems? GCC? ULS doesn't, Epilog doesn't (that I am aware of). GCC maybe?

[Gary Hair]

Well, from my personal experience, a laser tube will keep working right up until it doesn't..:confused:

You won't find a statement any more true than that! From anecdotal "evidence" I think that the more a laser is used the longer it will last - maybe it just seems longer.

Gary

[Dan Hintz]

The other point I was trying to be subtle about was that there are lots of stories about dead laser tubes less than 5 years old, but very few if any of those are Synrad tubes. I can only recall one story on this group of a Synrad early failure.
I doubt you'll find even a single story of anyone dieing in a zeppelin crash within the last 50-60 years, so one can conclude travel by zeppelin is the safest form of travel. Statistics with a limited number of data points can conclude nothing of significance.

Edit: Looks like Steve beat me to the punch... how many here have Synrad tubes in their machines?

[Dave Johnson29]

Statistics with a limited number of data points can conclude nothing of significance.


Dan, I draw your attention to my original reply, "very limited experience." Quoting out of context can be made to validate anything.

Nuff said?

[Darren Null]

To answer the original question....lasers work because they are full of gas. Over time the gas leaks out of the casing and that makes the laser work less well. Sooner or later your laser will fail because it doesn't have the right gas mix. If it lives that long....:

So. Eventually, your laser WILL fail. As far as I can tell (and please bear in mind that this is a guesstimate) if you have a higher power laser (which puts more stress on stuff) and if you run it hard (which increases wear) you're more likely to have an early failure. Beyond that it's a lottery.

[Mike Christen]

I have a epilog summit with a synrad tube 25watt. I bought the engraver used from epilog rep 2 years ago. The tube is dated 1996 and when I bought the machine they had no record of it being repaired, recharged, etc. I still use it all the time and it is more or less setup to be a permanent rotary engraver. It is still going strong, biggest problem is any vector cutting needing a radius or angle cut with it, not a good machine for that. But hey 1996 and still going strong, guess I'm lucky.

[Rodne Gold]

Over 10 lasers I have owned, most of em owned for 3-4 yrs I have had in excess of 10 failures of both Coherent and Synrad tubes ..some tubes lasting 3 months or less..some for 3 yrs + , all low powered tubes (rated 25 or 30w) and most of the failures have been sudden ...not just a slow loss of power. Currently I have 6 running , 3 with coherent , 3 with synrad.
I count myself lucky to have a working tube life of 3 yrs , I dont view 3 yrs as an expectation but a bonus.
Thats why a bumper to bumper warrantee in excess of a year is important.
Last tube I had swapped out (send old one back and get a reconditioned one) was a 30w Coherent in Nov 09
and it cost me in excess of $4k including postage to and from Germany.

[Richard Rumancik]

I communicated with Synrad on the topic of tube life several years ago. At that time I was told by a technician the 45,000 hours is referencing the gas lifetime, not the entire laser tube. He also suggested that if lasers are not returned for 10 years, it is reasonable to claim that the tubes have been proven to last more than 45,000 hours. (That would be assuming a 50% duty cycle.) You may agree or disagree with Synrad’s conclusion. I did not get the impression that they had dozens of lasers on a life cycle test. The statements were based on field experience. Not sure how they determined gas life, unless it was extrapolated from lab tests (if they know the rate of gas degradation, they could extrapolate to determine when the gas quality makes the tube unusable.)

Keep in mind that it is necessary to define what reduction of output wattage constitutes “end of life”. I’d be inclined to say a 25% drop in power represents end-of-life but I don’t know what measure the manufacturers use.

Elsewhere, Synrad makes this statement: “SYNRAD lasers have a shelf life of 10 years and a demonstrated operating gas lifetime of well over 45,000 hours of continuous operation.” (Emphasis is mine.) This does not say that there won’t be any OTHER failures in the 45,000 hours; just that the gas itself will still be useable over that period. BTW 45,000 hours is just over 5 years operating 24/7. So a laser running 8 hours a day could see a gas lifetime of 15 years.

I haven’t read anything that suggests that regassing is required due to leakage (although a leak would make the tube inoperable.) I think that the main reason why the tubes need to be regassed is because of reactions occurring over time in the gas mixture itself, which degrades and contaminates the mixture.

[Rodne Gold]

I don't think gas life is the issue , just about all my lasers failed suddenly or very quickly , which indicates either blown electronics (mostly a RF board) or another "catastrophic" cause rather than a slow gas leak or just gas degradation.
I have had worse service from Coherent tubes than Synrads.

[Dan Hintz]

Elsewhere, Synrad makes this statement: “SYNRAD lasers have a shelf life of 10 years and a demonstrated operating gas lifetime of well over 45,000 hours of continuous operation.” (Emphasis is mine.) This does not say that there won’t be any OTHER failures in the 45,000 hours; just that the gas itself will still be useable over that period. BTW 45,000 hours is just over 5 years operating 24/7. So a laser running 8 hours a day could see a gas lifetime of 15 years.
Ugh, such deceptive advertising. It's like saying the engine and drivetrain on this new car will last 20 years, but if the body falls apart from rust in 5 years, what's the point?

I thought we were talking strictly gas in this thread, but if we're talking the whole package then Rodney is right, the electronics are more often the weak link. Reliable RF transmission electronics are a tough nut to design for tube manufacturers, evidently... maybe if they shot for military-grade components instead of standard commercial grade the boards would last longer.

[Mike Null]

Electronics are indeed the more common problem with laser tubes.

Having been a member of three engraving forums for a number of years I can say that, one tube life is unpredictable, two there are any number of instances where tubes were replaced within a few months of installation and sometimes more than once.

Trotec still uses Synrad tubes on some, but not all, of their machines. My 45 watt has a Coherent tube. It is now 3 1/2 years old.

I operated two 100 watt water cooled Epilog machines which were 10 years old and in daily use. Neither had a tube replacement. Both had Synrad tubes.

[Mark Ross]

Another bad thing to do is not clean off the dust on the heat sinks on the RF supply. Our epilog looks like it is about to go on its third tube. We average 1-2 years from what I can gather.

However we run a minimum of 8 hours a day M-F. Sometimes two shifts.

[Richard Rumancik]

Ugh, such deceptive advertising. It's like saying the engine and drivetrain on this new car will last 20 years, but if the body falls apart from rust in 5 years, what's the point? . . .

That sounds like the first (and only) brand new car I bought 20-something years ago.

Sometimes a company's marketing group will take engineering data or field experience and use it in their advertising, and maybe even use it a bit out-of-context. If you don't read carefully, you can really be mislead. It may even make the engineering department a little uncomfortable.

I think Synrad is a respectable company and makes good lasers, but I have never been entirely happy with the statements in their advertising regarding life. I'd like to see them improve their warranty as well - a one year warranty is really not good enough in my opinion. (Some of the laser systems manufacturers may warrantee it for longer.)

I think GCC may be still using some Synrads but it is hard to tell from the data sheets.

[Dan Hintz]

Next time anyone's laser fails (and it's out of warranty), let me take a gander at the RF board first... let's see if I can't improve upon the design with some more reliable components.

[Rodne Gold]

The RF board is easy to repair , however you need an offboard controller and an oscilliscope to tune em..
Synrad will give you instructions

[Dan Hintz]

All I need are the frequencies of interest... I have some decent lab equipment, including function generators, power supplies, and digital storage scopes going to a couple hundred MHz. I'm not interested in radically changing the design, just upgrading the components used (and maybe a necessary design tweak or two to take the new components into account).