Post Print Smoke / Smell

I generally smell the most burn / material from the GF after it has completed cutting.

After the cut is done the head resets position and the fan turns off.

I have read that being able to leave the fan on for a brief while after the cut is done is something GF is “working on” - any updates on this? It would seem many people are getting puffs of smoke under materials and open the cover minutes later to find the smoke there and subsequently exiting into their workspace.

After the fan turns off - what happens to the air inside the GF? Is it sealed? If not, is the smoke escaping through the intake valves?

Unfortunately, the smokiest part is after cuts - this takes a toll on those with allergies / sensitivities.

I know there is residue left on the print, but it actually feels like smoke is being pushed out of the GF right after a print.



The fan should stay on for long enough to clear the smoke. If you are still getting smoke/smell, look for leaks in your ducting and make sure that the vent is clear, within specified length limits, and does not have too many bends.

My fans run for about 10 seconds after the job is considered complete.

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Mine runs for a while after the job and clears the thick smoke out. However, as has been noted before, there is smoke stuck under the work piece in the crumb tray. As soon as I move the work, it escapes. So I often move the piece to the side and close the forge again and wait a moment before removing anything.


I wish this were the case with mine! Does anyone else have this feature?

happens to me a lot, too. i really do wish we could keep the fan running even with the door open. or have a software button that would run the fan for 15 seconds, so we could do this:

and then hit the button.

it’s not so bad with cardboard, paper, or wood. but for the really smelly stuff?

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This has been standard behavior for quite a while. Previously, the fan shut off the instant the laser did, now it runs for another 10 seconds. That’s not what yours does?

I use one of these booster fans and it works great.


Yep. I expect I’ll drill some holes the depth of the bed in the honeycomb parallel to the floor so the trapped smoke can be extracted if I move mine upstairs from the basement.

Although the geek side of me wants to fab up a little bed tilter with an Arduino that I can attach to the rear of the bed and tilt it before I open the lid :grinning:


No - my fan does not run after the print as far as I can tell… there is the noise of the GF running constantly, but I think that’s for the coolant or something (?)

Unfortunately, I don’t think this will help. I am pretty sure the honeycomb is suspended in the tray, such that there is exit room there. When I have placed material so the back 1/2 inch or so is not covered, I can clearly see smoke being drawn from under the material during cuts.

The problem is that smoke collects in cells that are closed on top by the material (probably lots of turbulent flow under there). Without moving the material, that smoke is going to stay trapped there.

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the loudest part of the GF running is the fan. so that probably is the fan you’re hearing.

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There is a fan that kicks on when cutting… but when you turn the machine on and when it is idle there is a lot of noise… is that also a fan?

That’s the coolant pump. It runs continuously.

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I agree with this 100%. Need to let the user specify how long to run the fan after job finishes. Should default to 10 sec but be user definable (manual cooldown time).

right, but the fan noise continues for at short period of time after the cutting is done and the head moves back to it’s spot. that’s the loudest part.

I am using this by the way:

I am venting out of a residential window. I have it in the storm window and open the main window and attach the dryer vent each time I glowforge.

I plan to tape around the storm window on the inside with HVAC foil tape… but as I say I havent noticed that much smell when cutting… only after everything is done.

The flap does open when the GF is cutting, I have verified that from the outside. I think it is shut when it is not cutting.

Putting another fan in the system is not so much of option, nor is drilling any holes in the bottom of the GF or the GF in general.

The path to my window from the GF is an S shape. My GF is literally almost right at the window. I am using VERY little of the GF dryer vent.

The smell is almost something that would limit my use of the machine since I am so sensitive. My eyes burn after using the unit too.

Holes drilled back to front would give it an exit - have be one through every honeycomb section.

Thanks for writing. I’m glad you contacted us about this.

Even with proper filtration, small amounts of smoke and fumes can enter the air around your Glowforge, producing a detectable odor. You may also smell an odor when you open the Glowforge lid, even long after a print is complete. This is not harmful.

However, if you detect a strong, sharp smell that also causes eyes, nose, or throat irritation, or if there is visible smoke escaping while the lid is closed, shut off your Glowforge unit immediately. Smoke and fumes could be entering the room in excessive concentrations.

We’ve created an troubleshooting guide with illustrations. You can see it here:

If you’re still seeing or smelling excessive smoke or fumes when using Proofgrade materials, we’re here for you. Write us again and send us:

  • The name of the material you’re using
  • Photos of your Glowforge and your exhaust system

They are harmful if you have asthma, young children, other sensitivities or are concerned about particulates:

From the EPA: “articulate matter (PM), also known as particle pollution, is a complex mixture of extremely small particles and liquid droplets that get into the air. Once inhaled, these particles can affect the heart and lungs and cause serious health effects.”

If you can smell them, they’re there.

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