Machine still producing smoke

My Glowforge Pro is still producing a lot of smoke outside of the unit, even though the exhaust line is clear and the fan is running. Any suggestions beyond the default F.A.Q. page? Here are the support threads where I have described this problem:


A video of the problem is available at:

I have gone through all of the recommended self-checks for excessive smoke.

Yes, that is not supposed to happen. Have you removed the hose at the rear of the machine and checked the fan to see if the grill that covers it needs cleaning?

(Also, if your vent setup with the hose is longer than eight feet or has more than two 90 ° bends, you might need to install a booster fan in the line.)

Is that smoke coming from under the glowforge, or is it just a trick of the camera? When I had smoke come out of my machine (forgot to open the blast gate. Turns out thats important), the smoke came from the sides. Well, the sides of the front.

That’s not supposed to happen. What’s the source, pass through or underneath? How long is the vent hose you’re using? Anything over about 8-10 feet will need a booster fan inline on the hose.

Same if you have much in the way of curves or corners. My vent system, for instance, has 6 (:grimacing:) 90-degree corners before it leaves the house, so I have two booster fans, a 600 cfm and a 400 cfm, plus some extra boost from the range hood whose chimney it shares. That reduces my smoke to almost nothing, though I still put blue painter’s tape over the gaps when I cut acrylic.

It looks like it is coming from both the front and bottom.

I am using the provided exhaust hose and only have the curves shown in my video. I would be surprised if this due to a lack of a needed booster fan.

Okay, it’s hard to tell what’s going on outside of the screen shot, so it helps to ask. :slightly_smiling_face:

Did you remove the hose from the back of the machine and check the grill over the fan to see if it is clogged? That has to be cleaned periodically or smoke can start pouring out of the front of your machine if it gets clogged.

That is, indeed, a ton of smoke. Might be a trick of the video view but it looks like the Forge is really close to the wall, forcing a tight turn on the vent. Can you slide it way from the wall a little more and “soften” that turn in the hose? Might help with the flow.
Also, no idea if it will help your actual situation, but a booster fan certainly couldn’t hurt. The definite advantage is leaving it running well after the cut and after the internal fan auto shuts-down.
Good luck!


Thanks for the suggestions! I’ll disconnect the hose again and take another look at the fan when I return from my trip.

I’ll take some more detailed pictures of the rear of the forge in a few days when I return. I should note that this was working fine for a month and a half and that I still feel significant flow at the exhaust pipe’s exit when the forge is operating.

There is a fan on the inlet, so if the exhaust flow drops below its flow rate the case will suddenly be under positive pressure instead of negative. Probably not the best scheme.

Yea, in that case I’d definitely start thinking that @Jules has the right idea and some build-up somewhere is the issue.
This is a dirty business, this lasering…

Could I please get a response from GlowForge support? This is the second thread that I have opened on this topic and I would like to find a resolution ASAP.

Did you get a chance to check for buildup of crud on the fan grill?

There is little to no accumulation of crud on the back of the fan, I have only two bends, and the total run is 68”.

Can you show the exhaust hose connection?

Is it leaking there Too? Might be just the shadows but it looks like there might be smoke residue on the GF.


Seriously! This ticket’s been open for a week! The other (My Glowforge has picked up a nasty smoking habit) is open for a frickin’ MONTH! What happened to a max of 3 days to hear from Support?

Maybe we need to ping @Rita?