120mm Extractor Fan

I wanted to add an extraction system to my cellar hobby space, primarily for my SLA printer. I had a bunch of 120mm PC fans, and some carbon filter sheet. Drain pipe to route it to the outside was easy and cheap, so I quickly knocked together this thing to connect everything together.

Full paramterised OpenSCAD source is provided in attached zip file, and latest version will always be [on github](https://github.com/nistur/extractor).

Exported version supports 120x25mm PC fan and 90mm drain pipe.

Designed to print without supports, and models should be exported to be in the correct orientation.

Not much space in the enclosure for fan control hardware - I'm intending to control this externally and just run power into it.

I may update this to add a HEPA filter at some point, but I couldn't find a generic one to easily mount, so will probably have to resort to using one for a random vacuum cleaner, mounted within the 'connector' piece.

EDIT: Test print proved that the tol