DIY Laser Fume Extractor

 After purchasing a hobby laser cutter as any DIYer should, I quickly realized the fumes pumping out the window would be a problem. When the gas leaves the building, air must replace it, or it'll get sucked back in through any cracks. An open window in the bedroom helps. However, should any vapors return, I'd like them to be made harmless (and odorless). To mitigate this, I researched solutions and spent weeks designing my own. It must fit in the tight space under the laser cutter, be easy to open for filter replacement, and have quality parts.

 The construction is plywood screwed together, with silicon at all corners. The design is such that any leaks simply pull additional air in. So there's no risk of leaking gasses where it shouldn't. The worst* that can happen is the gas isn't filtered completely, and still gets pumped outside.

There are perfectly cut blocks slid into place over each component. This acts as a barrier to keep dirty air moving through the filters, and is removable for maintenance. Each loose part is lined with neoprene or window stripping. The perfect fit is because I also modeled this entire setup in 3D.

The finished product does a fine job, and isn't loud at all. Each of the filter and fan components is rated for around 250 cubic feet per minute capacity. Since the fan is at the end of the filter, it pulls in the walls of the box, creating an even better seal. No, that isn't a car engine filter attached to the fan. It's a HEPA filter, making sure any smoke or carbon is filtered out before running through the fan. My fancy test was lighting and blowing out a candle to see where the smoke pulled into the box. No leaks! At least not externally. Putting a scented candle at the inlet and my nose near the end yielded no odors, so it seems to be working. The purpose of this was not to go cheap, although it definitely saved money over any plug and play option.


Known downsides are the cost of filter parts. They weren't crazy, but there are other ways. The inlet being so close to the carbon filter is also an issue. It may develop preferred paths, lessening the filter ability over time. I can rotate the filter over time to help with this, or stick a piece of paper over the closest section of filter to diffuse the gasses around more, at the expense of a little suction. Cheers!