Smoke, Fume, Particulate Extractor

This project started with a desire for a low cost, but effective smoke extractor for my laser engraver and then took on a life of its own. These could be used for a variety of filtration needs including soldering, welding, particulate and/or VOC capture.

• Uses commercial off-the-shelf HEPA/activated carbon filters that cost less than $10 each 
• Can use a variety of mechanisms to move air, including shop vacuums, 120mm fans, inline duct fans eg, [https://www.amazon.com/dp/B0CFDKFYW3/?coliid=I2QCBW6S8N84LM&colid=2KK1UIAIKMCLC&psc=1&ref_=cm_sw_r_cp_ud_lstpd_5SYERS191X8KTQW39QGR ], and dust collectors. 
• Filters can be stacked (up to 3 in the small box and 4 in the large) to improve filtration but with a resultant increased demand in static pressure requirements. 
• Various connectors are included that should meet most needs including various duct and hose sizes, and popular 3d printed segmented flexible tubing (TeslaPunk or Hornberger). https://www.printables.com/model/107125-flexible-segmented-vacuum-hose-40mm-fits-dn40-pipe  https://www.printables.com/model/22486-flexible-segmented-hose-75mm 
• All connectors attach using a 120mm fan hole layout using either screws/nuts or screws with heat inserts.
• Filter for small box is a readily available car cabin filter (BW285) https://www.amazon.com/dp/B07T55BRF3/?coliid=I261VBR9YYR14R&colid=2KK1UIAIKMCLC&psc=1&ref_=cm_sw_r_cp_ud_lstpd_N6W97Q494XZJX3F346RV 
• Filter for large box is from a commercial air purifier (HY4866) https://www.amazon.com/dp/B0CF1GLSYS/?coliid=IC90R2XNBDE1I&colid=2KK1UIAIKMCLC&psc=1&ref_=cm_sw_r_cp_ud_lstpd_N6W97Q494XZJX3F346RV 
• Reversing the filters/air flow and removing the lids (large & small box) and blocking one outlet (small box) these could be used for small, clean-air stations akin to a mini laminar flow hood.
• An activated carbon box is available (holds approx 1lb./455g) that can be added to the small box for additional capture of VOC's
• Use a layer or two of paper towels on top of HEPA filters as a pre-filter