4 inch inline fan filter

I have a laser that I use both for engraving wood, metal, and occasionally PVC (yes, I know all about the chlorine). The fumes from certain materials actually started making the bearings in an inline fan start squealing and accumulating layers of caked on materials on the fan blades. In an attempt to fix this, I created an inline filter that can use various filters for multiple applications. I use these vent filters from Menards which catch the bulk of the particles alone with a mesh filter incase any larger particles make it through. For materials that you're really not supposed to laser cut or engrave*, I switch out the vent filter for an actual face mask, yes, an actual face mask- this significantly cuts down on the airflow from the 195 cfm fan but is worth saving the bearings. 
* fan vents fumes outdoors, definitely not intended to purify or clean the fumes, fumes should still be vented outdoors

Filter has been scaled to both 3 inch, 2 inch and  5 inch for testing and will scale beautifully as long as all x,y,z are scaled equally and proportionally. (eg, you want a 3 inch filter so you need to scale it at 75% instead of 100%-  x=75%, y=75%, z=75%.

Dimensions:

99mm diameter connector to fit into 4 inch flexible duct.

2.3mm recess inside each housing (4.6mm combined) for filter media.

12.97mm thickness of square housing requiring at least 28mm or longer bolts. 

10.3 mm diameter for bolts (M8 or smaller recommended)

Additional 3d printed parts used in my build:

Customizable filter mesh: https://makerworld.com/en/models/966311#profileId-937066

Customizable nuts, bolts, and washers: https://makerworld.com/en/models/55381?from=search#profileId-92739

Not for commercial resale!