Great idea. The advent of "inexpensive" 3D printers really opens up the door for many ideas that otherwise would never see the light of day. The real issue with small DIY carbon scrubbers is mainly sourcing a fan with enough pulling power to suck a sufficient quantity of air volume through the carbon base. PC fans lack greatly in this capacity. With a carbon base thick enough to provide real scrubbing effect 99.9% of all PC based fans will have nearly 0cfm through the carbon due to lack of pulling power.