I recently decided to try to get into simple electronics work, and dabble some with microcontrollers. After finishing a few early practice projects I decided I needed a way to deal with the soldering fumes before I wanted to embark on anything larger. I decided it would be an interesting mini-project to build one myself, and this is what I came up with.

It uses a standard 120mm PC fan, and a handful of other parts that were easy enough to source on Amazon or my local Microcenter. I'm already fairly comfortable with 3D printing and basic CAD, so the project is housed in two custom 3D printed cases (two parts each). The base contains the li-ion battery and most of the other electronics. The top contains the fan and filter. 

The two cases are connected with some 3/4" LocLine. This gives some flexibility in positioning the fan, while giving a convenient and concealed/protected path for the fan wires. The LocLine snaps into connection points on the 3D printed cases. The top case pieces are a friction fit, as once the fan is screwed in place the only "weight" they have to hold is the filter. The bottom case is held together with some threaded inserts and M3 bolts.

In the bottom base there's a plug to connect the battery to a simple circuit; a momentary switch and battery status indicator, wired in parallel with a simple fan controller.  The fan wire is run down through the LocLine and connected to the controller. With the battery connected, the knob controls the fan speed (or turns it off entirely), while the momentary switch temporarily displays the current charge state of the battery on the indicator.

So far the extractor has worked quite well, and I look forward to having it for future projects. I have included links to the parts I used (excluding the 3D printed ones and the M3 bolts/heatset inserts) in the components section. The `.step` files for the 3D printed parts are in the files section, and the OnShape source can be found here, if you want to make adjustments (different LocLine size, different fan/filter size, etc.  

I have a few ideas for future improvements.  I'd like to provided access to the battery charging port without disassembling the bottom case, so a hole and way to mount that cable/port somewhere. I haven't used the extractor long enough for heat to be a problem, but I'd also like to add some airflow to the bottom case; I have a couple tiny little 20mm fans I'd likely use for that purpose, although I'd likely need to either make the entire bottom larger, or have them protrude from it to have space for even those. Ideally they'd come on automatically both along-side the larger fan, and when charging the battery.