Glowforge takes 40 minutes to more than 1 hour to cool down to print

I just started to use my Glowforge in an airconditioned room at about 72F. Everytime I print, my Glowforge will take between 45 mins to more than 1 hour to cool down to print. This is extremely fustrating. What makes it worse is that right after a successful print and when I start the next print, the Glowforge will go into a cooling mode, taking 45mins or more again!!! This is ridiculous.

  1. Is there sometime wrong with my Glowforge?
  2. How can I tell what is the temperature my Glowforge is sensing at any moment?
  3. Where is the temperature sensor located?
  4. Is there a BUG in the firmware that requires it to go through a compulsory cooling down mode even though my room is within the operating temperature of my Glowforge?

Any kind of help is appreciated.

What model :glowforge: are you using?

The operating temps are:
60-75 Basic
60-81 Pro

It may be a simple matter of not enough airflow around the :glowforge:
Have you cleaned the fans, confirmed the exhaust is clear and air is properly exiting the machine?

There is no temperature readout available to users at this point.
Most of us have a temperature sensing device (laser gun etc), or some other method of determining the temperature around the :glowforge:

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Running a CO2 laser too hot is a very bad thing. The life of the tube is reduced significantly if allowed to run too hot. When the laser is run it generates heat. The Glowforge has cooling liquid that circulates around the laser tube to help cool it. In the case of the Pro model there is a peltier cooling system to help cool the cooling liquid, the basic model does not have this peltier system and relies on air flow to help cool the liquid. As Houdini7 said, check your airflow - make sure intake (front right hand lower corner) and exhaust are clear. The exhaust grate in the back can get quite dirty which will reduce the air flow.


Also make sure you don’t have hot air coming back in through your exhaust. There’s nothing wrong with the software… I run mine at 72. Can’t say for sure about your machine, but likely it’s just warmer inside than you realize.

Other than checking for a build-up of debris, you could aim a fan at your machine to help with airflow and/or set your AC a bit cooler to see if that helps.

I don’t think everyone’s 72 is the same, either. I’d at least try turning the A/C down two degrees to see what happens.

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There are also some great tricks floating around the forum for helping keep your GF cool during operation. Here’s a search to get you started:

Your Glowforge features a closed-loop liquid cooling system that uses the air from the room to remove heat. It is designed to be used when the temperature next to your Glowforge is between 60 degrees Fahrenheit (16 Celsius) and 75 degrees Fahrenheit (24 Celsius). To check, put a room thermometer next to the right hand side of the Glowforge; it draws in air from underneath, on the right.

You can try any of these things to improve warm-weather performance:

  • Try printing with no material on the bed (so as not to generate smoke and fumes) and no exhaust hose attached. If this works, then the problem may be that your exhaust hose is constricting the flow of air out of the unit, preventing cooling.

  • Examine the bottom-right side of your Glowforge, and ensure that there is no fabric or other flexible material underneath it, like a tablecloth. There are air intake vents, and if they become obstructed, it makes cooling less effective.

  • Try pointing a fan at the right side of your Glowforge. If there is warm air around the intake, this could help it cool off.

  • Power off your Glowforge when you are not using it. When your Glowforge sits idle, the fans are off, so heat can build up

  • Just wait. Your print may take a little longer when it’s warm, but your Glowforge will protect itself and make sure it cools enough to prevent any loss of power or damage. It’s clever enough to pick up from exactly where it left off, even if it needs to pause to cool down during the print!

  • Ensure that the sun isn’t shining on the lid. This could cause the inside of your Glowforge to heat up.

  • If you are venting outdoors, ensure that extreme temperatures or humidity do not enter the Glowforge unit through the exhaust hose. Disconnect the hose from the outside air when the Glowforge is not in use.

  • Turn your Glowforge off and open the lid for a few minutes before trying again. It’s possible for the air in your Glowforge to heat up, just like a car in the sun on a hot day, opening the lid will help that warm air to escape and your Glowforge to cool down.

If you are still running into trouble, please let us know the following so that we can investigate further:

  1. A description of the things you tried and what happened

  2. If possible, place a thermometer next to your Glowforge on the right hand side and measure the temperature there; if not, estimate the room temperature

  3. The date and time (including time zone) when you had the problem

  4. Take a picture of the exhaust hose behind your Glowforge that includes the part where it connects to your Glowforge, and the part where it exits the room

Hi everyone,

Thanks for your advices! I just started to use my GF and everything is new. Airflow is very good and there is no obstruction to the air intake and exhaust. I suspect that although the thermometer in my room says 72F, the actual temperature inside the GF may be higher. I brought a huge external fan and blew cold air towards the right side of my GF. That shortened the cooling down time incredibly.

By the way, does anyone know where is the temperature sensor located inside the basic GF?

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I’m glad to hear the fan improved things!

The sensor is measuring the temperature of the liquid in the cooling system, so even if the room is within the operating temperature range, your Glowforge may need to spend some time cooling to get the coolant back down within the operating temperature range. Making sure that the air intake on the right side of your Glowforge is clear of obstructions, and has a good supply of cool air, will help speed the cooling process.

I’m going to close this thread - if the problem reoccurs, go ahead and post a new topic. Thanks for letting us know about this!