Life expectancy of the Glowforge tube


#1

How long can I expect the Glowforge tube to last me and also what is the replacement cost to buy a new one.


#2

I think something like 10000 hours has been mentioned and replacements $500.

In contrast a cheap Chinese tube lasts about 2000 hours and costs about $150.


#3

Haven’t seen any prediction from the company or information about the specific manufacturer here. Must be info from an outside source?


#4

Perhaps I imagined it. I think Dan said 2 years of heavy use. I have seen Reci tubes advertise 10000 hours but rumour is that GF use Yongli.


#5

There are 8760 hours in a year. So a tube rated for 10000 hours would run continuously for about 1.2 years. So a tube rated for 10K hours, that’s used for 8 hours/day, ought to last 3.6 years. Except the laser isn’t on all the time. It has a duty cycle that’s probably a lot less than 100%. If the laser has a duty cycle of 50% on average, the 10K tube will now last 7.2 years.

I only use my cutter for a couple of hours at most, every few days at most. The duty cycle (hours/day that the laser is powered divided by hours/day) on my GF is much, much less than 100%. If it’s got a 10K tube it ought to last me most of my remaining life. A 5K tube might even do it.

Worth mentioning that the meaning of “rated life” for a laser is the same as a light bulb. The “hours” is a statistical number, not an actual count-down clock. And what the statistics are based on is dependent on the manufacturer. For example, “rated life” might be the amount of time before, on average, 20% of the tubes do not meet operating specifications anymore. It could mean the point in time when they think 50% of the tubes will have failed outright. Reliability estimates (MTBF) is tricky stuff and the data is easy to “game”. So a number without the details of how it was tested and what constitutes “failure” is kind of worthless.


#6

No one knows. Anything we tell you is pure speculation. :slightly_smiling_face:


#7

Except laser tubes apparently deteriorate when they aren’t used, i.e. they have a shelf life. I haven’t seen any figures though.


#8

Six


#9

OK. You motivated me to go do some studying on Laser reliability (I deal with product reliability as part of my job). What I learned after a couple of hours of reading can be summed up as follows:

No seal is perfect. Everything leaks. Sealed CO2 lasers “leak” (though “diffusion” is a better description of the process I think. “leak” would imply a defect like a crack maybe). As the gas pressure in the tube goes down (and diffusion runs in both directions so outside air infiltrates to some degree, too, which changes the mix) the laser’s performance drops.

Higher temperatures would accelerate the rate of diffusion (the laws of physics demand this). But just sitting unpowered the tube is going to degrade, but slower. It’s not a big stretch to guess it’s governed by the Arrhenius equation (since most everything is), which basically means rate of diffusion increases exponentially with increasing temperature. So the tube will die a lot faster the hotter you run it. Doing more high-power jobs will wear it out faster than lower power. Conversely, the tube should last longer the cooler you keep. But no one appears to publish any actual reliability data. The figures quoted for expected lifetime vary widely, and pretty much every spec I looked at had the lifetime rated as a spread of years (like “3 to 5”).

So the answer to the question “how long will the tube in my GF last?” would probably be somewhat vague even if we had specs from whoever makes the tube. Best answer is probably “until it doesn’t work anymore”.

I’m sure the GF keeps track of it, and I admit it wouldn’t do us much good at the moment (though as machines age in the field, the data would start to be useful), but it would also be nice if we could get the total hours of operation on the tube as part of a “dashboard” function in the GFUI…


#10

Yes but I think there is another wear mechanism when it is running. I think the ionisation causes chemical changes to the gas mix.


#11

Thanks for asking!

The Glowforge tube is rated by the manufacturer for 2 years. We’re doing lifetime testing now to dial that in a little more closely.

The tube is covered under the warranty. Out of warranty, we’ll replace it and realign it for you for $499, including roundtrip shipping in the US. We’ll also have a replacement tube part available for purchase.


#12