Cooling for over an hour

Today was the big day! Emails have me pumped up, ready to open and print in minutes!

I got it all set up in my workshop, which is inside a house with fans for cooling but no AC. I didn’t get a temp reading but outside it was in the 80’s. I’m assuming inside in the shade with fans it would be less.

At first it went straight to cooling and I couldn’t even load a file. Then I turned it off and pointed fans at it for a few hours. Then I tried again and got far enough to press print…but when it told me to press the button it immediately said it was paused with no explanation. Then when I hit cancel it said it needed to cool.

Big day felt like a big let down. I might not be able to use this thing. No refunds now. I wish I would have known I couldn’t use it in my workshop. From the reading I’ve done on the Recent revelations of the limits on temperature it seems like the only place I could use it is in an air conditioned room.

Anybody have plans to hack together an Air Conditioner just for the Glowforge? I’d rather not try and cool my whole shop down to 72 degrees.

It really seems like a huge bummer, any fixes or tips from the company?


Glad you got your Glowforge, sad you got got the heat wave issue. I have to admit, although I knew the theoretical issue of needing to cool a laser and that heat was a potential problem, I never thought that it would be so widespread. In the almost two year ramp up to delivery, venting and noise were well-discussed, shop environment not so much. In my mind the Glowforge would be an indoor, office machine and I have air conditioning in my work office, at home and even at my cabin in the woods. So many folks don’t have air conditioning and don’t really need it. This is a puzzle. Room swamp coolers or window units seem to be what is required.


There is no need to cool the entire shop but you will have to get the immediate area down to 76-77 or so.
An 8-10 kbtu unit blowing at it will do the trick


Are there any indicators as to when a firmware update has been pushed? Wondering if it didn’t have the latest firmware onboard when it went out the door and maybe the machine hadn’t had a chance to update to the new cooling plans they’ve pushed?


If you plan to use your Glowforge unit in ambient temperatures up to 75F, your Glowforge Basic should be fine. I’ll look into this more tomorrow and will update this thread.


That would be great. But, unfortunately, we have no idea when an update is happening or when one has happened.


My “shop” is a normal house with insulation and everything. My actual house is tiny, about 144 sq ft. I’d never be able to fit the Glowforge in my tiny house and I have all my other things in my “shop house”. I have a 3d printer, CNC machine, full wood shop, etc. I don’t think it’s an extreme situation. All my other shop tools work in my shop. I don’t run a sweat shop, just usually open the windows and turn on the fans for both the heat and ventilation.

I do feel like if any piece of equipment was sensitive enough not to work without an external chiller in most of the country it should have a huge disclaimer. I know I’m past the point of no return here but for anybody else who might be considering buying one they should know. It should say in bold letters WILL NOT WORK WITHOUT AN EXTERNAL AIR CHILLER. I know the Pro is supposed to be better at this and maybe I would have gotten that if it were discussed more. I didn’t need the big laser or pass through for that money. Now I’m stuck buying an external air chiller for my “stand alone” machine. I know now that other laser cutters have external coolers so I’m not faulting them for needing it, just for selling a machine that needs one without one. Temperatures around the country around getting any cooler.

Haven’t been able to print anything yet.
Feeling disappointed. :slightly_frowning_face:


There’s been a fair amount of discussion about this and the variability in what “normal” temperatures are in various parts of the country & the world. As a result last month they pushed out new cooling handling in the software that may have been on your machine yet (needed to download from the cloud).

Also, if you just got it and unpacked and tried to use it, it might be overly warm from the transit - where the vehicles might have been far warmer and thus the machine still very warm.

I use mine in an unconditioned basement that is insulated so doesn’t get the advantage of the earth heatsink. It’s been in the low to mid-80sF for most of the past couple of months. Before the latest update, mine wouldn’t run above 77F even though the humidity levels were low (40%) so I was perfectly comfortable. After the update it hasn’t had an issue. In fact this week I ran a project with multiple runs of up to 3 hours at a clip in an 81F temps without it stopping or needing a cooling cycle.

I did work on an auxiliary cooling approach but wasn’t ultimately successful and didn’t keep tweaking it due to the update removing my issue. My posts on my GF cooler might give you some help in knowing what didn’t work as well as where the cooling parts are in the machine and could give you someplace to start. Alternatively, a room a/c unit, especially if the cooling airflow was near or directed toward the GF should remedy the issue as well.


Part of the reason I ended up with a Pro is internet threads I’d read about low cost laser cutters often had somebody reply and say before you get too excited about the price, don’t forget you’re going to need a water pump and a bucket and probably a water chiller if you want to do anything real with it.

So, though I wasn’t sure if what I wanted to do with it would count as “real”, but it seemed like avoiding a regret like this one was worth the price.


The manual was updated yesterday but it still says you should operate between 60 and 75F.

Print when the ambient temperature is within the following ranges. Printing outside these
ranges may cause your print to pause periodically or fail to complete.:
● Basic: Below 60 degrees Fahrenheit (16 Celsius) or over 75 degrees Fahrenheit (24
● Pro: Below 60 degrees Fahrenheit (16 Celsius) or over 81 degrees Fahrenheit (27

Not sure how you are getting away with it hotter than the limit for even the pro. Does humidity make a big difference to cooling inanimate objects?

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not unless they’re wet too i shouldn’t think

Basically you’re talking about wind chill and wet bulb temperatures.

Inanimate objects aren’t impacted by wind chill aside from cooling to ambient faster. For example, an exposed water pipe at my house won’t freeze if the windchill is 10 degrees f and ambient is 35f.

Wet bulb temps are probably more accurate in the sense of measuring the environment of a workspace.

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Not sure why humidity would matter except it was one of the factors listed in one of the GF posts here I believe.

I also don’t know that it didn’t pause because I wasn’t sitting there watching it - I was working on other designs but the jobs finished in the time the GFUI initially reported as the time required for the jobs. I would have expected that it would have taken longer if it had to pause to cool. It could also be that the listed ranges are “optimum” but that there is a tolerance outside the listed temps - like “best use by” dates for food freshness.


I can imagine air laden with water might cool slightly better because it might have a higher specific heat capacity than dry air. However it seems very dry where you are so that doesn’t explain it.

Correct. The basement isn’t air conditioned but it is dehumidified because otherwise we get that damp musty basement thing going on :slight_smile:

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not really. i was referring to the effect of local humidity on evaporative cooling, which is why i suggested it might only matter if the item was wet.

we keep our dehumidifier at like 50% juuuuust in case. it wasn’t really musty before, but we did have that catastrophic aquarium failure…

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Just for example:

80 degrees (dry bulb temp) at 100% humidity and 29.92" pressure has a wet bulb temperature of 80 degrees.

80 degrees (dry bulb temp) at 75% humidity and 29.92" pressure has a wet bulb temperature of 74 degrees.

80 degrees (dry bulb temp) at 50% humidity and 29.92" pressure has a wet bulb temperature of 64 degrees.

80 degrees (dry bulb temp) at 25% humidity and 29.92" pressure has a wet bulb temperature of 58 degrees.

Humid air releases less heat through evaporative cooling.

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I hope it works today, I’ll take temp readings in the room and humidity as well. If this needs its own AC unit I guess that’s what I have to do at this point. Where should I point the AC to? I have the unit in front of a window (shades drawn, no direct sun) for ventilation exhaust tube access but I guess I don’t want to vent outside and have the AC pull the fumes back in right? Do window units pull from outside or recirculating inside air? This is all stuff I didn’t think I’d have to deal with.

sorry, yes, you’re right, i misread the meaning of your earlier paragraph.

what i mostly took issue with is your frozen pipe scenario because i don’t think it’s germane. i mean yes sure someone will probably be upset that their basic laser doesn’t work in 90F environments with 100% humidity but that’s not really relevant either; i just made too many assumptions i didn’t spell out.

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Window a/c units recirculate the interior air, they don’t pull air in.

The right front bottom is where the air is going into the GF and the heat exchanger is right above that underneath the big button. It’s the black perforated plate you see if you look inside on the right.