The building that houses my laser cutter has 2' thick rubble filled stone walls so having already got the physical and mental scar tissue from previous attempts to pierce holes through them I decided that venting the fumes through a nearby window made much more sense.

Hence this design.

To fit it I removed the pane of glass and replaced it with a cut sheet of 4mm cast acrylic (drawing included so you can tweak it to fit your size of window).

When designing it I had a complete brain fart and worked on the basis of my laser extractor tube being 8". It was only after many many hours of printing; when I got to the last part (the internal tube mount) that I noticed the tube was a bit big and realised that the tube is actually 6" DOH! :-(

.....or the design cleverly uses the venturi effect by expanding the 6" inlet into an 8" cavity to prevent leakage :-) You choose!

There are DXF files included for the gaskets each side of the acrylic window pane (I used some 3mm neoprene which is a bit dodgy to laser cut but I figured I could chance it for a one off). There's also a DXF for the 3mm acrylic blade that shuts off the vent.

I've included stl's for two versions of the tube mount. One straight and one angled that matches the return around my window.

There is a spacer between the acrylic window pane and the blade holder so that the blade clears the glazing bar above the unit. For me, 14mm is ideal but I've included the Fusion 360 file so you can change that.

If I were to print/cut the parts again, I'd not leave the 1mm gap between the blade and blade holder; half a mm would be fine.

As well as the printed parts and laser cut blade and replacement window pane you'll need six M5x40 socket head screws, washers and heatset inserts.

I printed in PETG as it should stand the exposure to the UV sunlight.

[Edit 16th November 2020]

I've replace the DXF for the blade with a version that has less clearance between it and the blade holder. I've also uploaded an STL of that version as someone asked for it.