Fan seems to blow smoke out the front of the unit

I have checked and cleaned the exhaust fan, it seems to be pulling stuff out the back just fine and I have a squirrel fan inline to help pull out the window. However I can see feel air blowing right out the front of the unit when it does things. From looking inside and feeling where the air is coming from it feels like the air assist fan is blowing the smoke out the front? Do I still not have enough pressure out the back? It seems to pulling air out pretty hard when I check outside and inside the unit.

The air seems to coming out the front surprisingly quickly. Are there other fans in there? Or something else that might be obstructing the air flow?


When is the last time you cleaned the fan/ grill on the back of the machine?

I Cleaned the fan right before posting this. So today :slight_smile:

If you laser the far left or right of the bed area, the air assist fan can blow the smoke through the sides of the front panel door. Because of how hard this fan blows across the material surface, no amount of fan on the exhaust can prevent it from happening.

I myself just added a silicone flap on the inside of the door to block this escape path.

You can either do this or just be aware of where the cutting happens on the bed in relation to these gaps and avoid it.

Your fan may be inhibiting airflow, not helping, or simply be insufficient for the ducting layout you have. Adding a fan doesn’t guarantee it will improve things, it has to be rated at least as good or higher than the built-in exhaust fan, for even the standard 8’ layout.

I have never had any smoke or odor “escape” from my machine - and I work a lot with acrylic, which has a very strong odor.

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I looked around found people recommending cutting the grill out the back of the unit. I did that and now everything blows out brilliantly :slight_smile:


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From the conversation, it appears that you might have been printing with modifications in place to the case of your Glowforge. Modifications to the case could allow infrared and ultraviolet light, heat, smoke, and fumes to escape, which could be hazardous to people. The Glowforge manual at describes how to operate your Glowforge safely.

This discussion is outside our team’s scopes, so I’ve moved it to the Beyond the Manual where it can continue.

When I cut leather, I get that smell in my basement shop. That irritates my wifes asthma. The GF feeds into the same chimney as my water heater, all connections are good, tight and taped, no problem with smoke or cutting wood. Suggestions and hints or links to building my own filter unit?

The machine is designed to operate under negative pressure, no odor or smoke should escape from the gaps around the lid and door. The exhaust fan is capable of maintaining this negative pressure if the duct is just a short distance with minimal bends, per the instructions.

If you are feeding into a longer or more convoluted duct path, the exhaust fan alone may not be sufficient to drive the air and the machine will no longer be under negative pressure, then fumes may escape.

The solution is to put an additional in-line fan into the duct system, preferably as close to where it leaves the building so that the entire duct is also under negative pressure. With a fan of sufficient airflow rating, you can even disable the machine’s exhaust fan, which reduces operating noise significantly.

Ok, Thankyou That explains a lot since in summer I vent it differently.
Does anybody know how long the filter unit filter will last?

It depends on what and how much you are printing. Material, cut vs. engrave, etc.

Worst case, you can fill a cartridge in a day. Some people have them for months.

They provide some rough estimates here. You’ll note Draftboard is not on the list, but they state it will dramatically reduce the life of the filter cartridge.

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