Summary

I solder electronic components and wires from time to time and I was told solder fumes are rather toxic.

I did not want to invest a lot since it's only a casual hobby for me.

There are a lot of fume extractors here but I wanted to design my own version since it is also a way for me to develop my skills with Fusion 360. And I also wanted to use what was present in my closets, ie a 5v USB fan and a bunch of 5mm magnets I got from a previous project.

The cool feature I designed is the way the parts attach to each other: they snap thanks to small round magnets and that makes changing the filter a very easy task.

A video of the snap-on magnetic system:
https://youtu.be/Gog3wz5vRpU

You can choose to build it with only one carbon-based filter in front of the sucking side of the fan; or upgrade it and add a second filter, attached in front of the opposite blowing side. The main frame can be used for both versions so you can decide later if you want to add the second filter. Adding the second filter improves the filtration of course, but also reduces the sucking power (meaning you should do your soldering closer to the extractor).

So I ended up with this design that I find very satisfying and useful (it works!)

My USB fan comes with a metallic grid I re-used to beautifully finalize the design with its own screws (the model I used is referenced below).

Components list:

one '80x80x25mm' USB fan (see model below)
16 '5x1.5mm' magnets if you want a one-sided version (32 if you want the double-sided version) - available on Amazon, see below
PLA of course
one or two square piece of 80mm wide, 5mm thick carbon filter (cut it from a furnace or air purifier sheet)
CA glue to attach the magnets to the frames

The fan I used:
https://www.amazon.fr/gp/product/B06XRCDZDH

5mm magnets:
https://www.amazon.fr/gp/product/B00TACFNXS

A video of the working extractor in action:
https://youtu.be/yA7RCwI52VQ

Print Settings

Printer Brand:

Prusa

                                            Printer:                      
I3 MK3S

Rafts:

                                            Supports:                      
No

Resolution:

0.20

                                            Infill:                      
15%

Filament:

Prusament PLA

                Pearl Mouse Grey                    
                        Notes:                     Prints with no supports. Mind the print quality of the slots designed to shelter the magnets. It's a tight fit.

You need 1 FanCase, 1 FanFilterHolder (2 for the double-sided version) and 1 FanFilterFace (2 again if you want a double-sided version).

Post-Printing

Assembly

Magnets want nothing more than jump and snap at each other, even when you don't want them to. Attaching them to PLA can be tricky. Two things to have in mind:

Mind the polarity. If you are not careful you may end up with parts that will repel instead of attracting each other.
Be patient and find a strategy when you insert a magnet in a previously glue-filled cavity. If you don't, magnets will stick to your fingers instead of sticking in their slot. They also tend to find their way out and jump at their fellow magnets in your hand or at any magnet too close.

So double or triple-check polarity before you glue. And have a wooden or plastic narrow tool to help you push the magnets in and keep them in place while the glue dries.

Quick tip to make sure all magnets are oriented with the right polarity on a same face:
your stock of magnets is basically a cylinder made of small magnets. Don't try to separate them. Instead, use the column-cylinder of magnets as a stick to push a magnet in its glue-filled slot. Once inserted, simply slide the magnets-cylinder sideways while maintaining pressure. You may still have to push the magnet a little further down with a plastic or wooden tool. Keep one at hand since CA glue is fast. That method solves the two challenges I mentioned before.

How I Designed This

This is the third version of my DYI NAS server. I did not publish the two previous versions. They worked fine but had some issues I solved with this design. Feel free to ask questions.