Taping off forge to prevent odor spilling directly into lungs - doesn't bode well for the filter?


I’m at the end of a particularly smoky run of maple beer taps for a local brewery and have taken to taping off the entire forge to prevent the smoke from filling the entire house. It leaks from almost every joint. Anyone else have this problem? It also pours out the vent into the outside. I can’t imagine how the filter will work if it literally pours from the cracks in the machine.


The forge works through negative pressure. When it is functioning properly, air should be sucked into all those cracks. It is not designed to be airtight. Have you cleaned the fan and grill for the vent or made sure the fan is actually working? I’m not sure taping it up as such is a great idea.


Yeah looks like something is amiss with your ventilation setup, that should all be whisked away.


If you have visible smoke coming through the front/top/sides during a print, something isn’t right. Smoke should only go out through the exhaust.

Support can view your machine logs and verify the fans are running at speed. You’ll save a round-trip by providing a date and time (including time zone) when you ran a cut that leaked everywhere.

Video of the smoke exiting the front would be helpful to them as well.

Good luck and stay safe.


Yes indeed. your exhaust fan is clearly not working correctly or your port cover to the outside is NOT opening.


Definitely not venting correctly, as stated, the inside is under negative pressure, no smoke should be coming out from those areas.

Have you checked the exhaust fan? Depending on what you’re working with, they get pretty gummed up.


Interesting. I am also engraving maple beer taps for my local brewery. Have done at least a hundred so far on three sides. It is one of the least smelly of anything I have done. Zero smell or smoke until the lid is lifted, and almost none at that time because the crumb tray is removed so no place for smoke to be trapped.


Either your exhaust fan isn’t working or the exhaust fan grill is face loaded. The grill is most likely I think.

I had that issue with the PRU and started taping the cracks.the build-up on the grill is gradual and I finally checked the grill and found it almost completely occluded.
When the machine is breathing right and your exhaust run has no leaks there is zero smell during operation.


Please remove all of the tape from the cracks, it needs to be open for air flow into the machine. That exhaust fan will burn out.

If you have smoke coming out of the cracks, you need to check the air intake (make sure nothing is blocking it underneath the right side), and clean your exhaust port using the cleaning instructions at the link below.


Check the exhaust fan carefully, after removing the hose - a buildup there will cause smoke to start coming out of the cracks.


Thanks I just did that and it helped tremendously!


I bought a special adapter for my vacuum cleaner brush (long horsehair upholstery style brush) so I could get that fan cleaned. Amazing how much crap gets deposited on it. :smile:


The first thing the intake air does is pass over the heat exchanger, so if it were restricted the machine would overheat quickly and shut down.
With the exhaust restricted the intake fans pressurize the interior forcing smoke out of every crack in the machine.

Depending on how long this condition has existed, the air path through the head can also be affected, because the tiny fan in the head that prevents smoke from getting the lens dirty draws air from the interior of the machine.
In my case I noticed a slight fog on the inside of the window on the side if the head.
I had to unscrew the window to get it clean, and I saw the entire beam path needed cleaning.
So I removed the window, the mirror and the lens to clean them with the wipes, and used alcohol and Q-tips to swab out the beam path behind the window and the lens bore.
Be gentle with the mechanism that the lens sits on which moves up and down to focus.

Also a good opportunity to clean the blades on that tiny fan.
It might sound complicated, but cleaning the head is a snap.
Just be careful because I’m sure that head is one of the most expensive components of the machine.

*Note that this is all my own solution to the problems I found and is in no way official.


Just following up after all the tons of good advice you’ve already gotten to ask: how long is your exhaust run?


I don’t think so. The main air intake is underneath and air is sucked in by the intake fans. The big design flaw is that if the exhaust flow falls below the inlet flow the pressure switches to positive. If it had just an exhaust fan like most laser cutters then it would never have positive pressure.


If it never had positive pressure then the volume through the cooling system would be entirely based on the exhaust and as that got clogged the cooling system would fail.

I really hate to have pain when I am hurt but it does make me pay attention. Smoke coming out of the Glowforge can be like that.


The glowforge does have an exhaust fan, and it runs at a higher displacement than the intake fans. When the exhaust flow restricts, the intake volume overcomes the exhaust and the extra is pushed out the cracks.

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