Self powered air filter

This model is a self contained, battery powered, airfilter for a print enclosure.  It uses a 4020 fan, two  AA sized batteries and 3/8" (10mm) thick activated carbon filter media that is cut to fit & stacked in the shell. Do not overstuff the shell, you don't want to block off air flow.

Two versions of the fan body are included, one for fans with 32mm screw spacing and one for fans with   35mm screw spacing. The fan body should be printed with flat side down & walls upright with supports everywhere.

The media shell slides onto the bottom of the fan body.  

My build used two 14500 li-on batteries and a 12v 4020 fan.  A MT3608 DC-DC boost circuit board, like this one: https://www.amazon.com/dp/B0C858YYQ1  was used to provide 12v for the fan.   The battery contacts used were like these: https://www.amazon.com/gp/product/B072379C1  and attached with CA glue.  The hole for the power switch was sized for a switch like these:  https://www.amazon.com/gp/product/B07T1JG6BD.   

See pics for wiring & assembly details.  Alternative fan voltage and voltage regulators could be used, Just be sure the combination of batteries, regulator and fan are appropriate.   After taking the pictures, the model was modified for a 46mm wide internal space for a better fit with the voltage regulator circuit board.

Voltage output should be adjusted prior to making the final connections to switch and fan and installing the regulator in the case

The battery cover slides in to cover the battery and electronics, the fan cover slides in to cover the fan output.

.STEP and Fusion 360 source are provided.   

Please note that the F360 source includes use of the free  “ParametricText” F360 add-in to set the screw spacing info inset into the fan body bottom.  The user parameter “FanScrewSpace" is used to set the fan screw spacing.  The user parameter “FanScrew” sets the hole size for the fan screw.  This has only been tested with 32mm and 35mm.