SOTW #17 - Glass Top Fuigo - What's going on in there?

A look at the inside operation of a prototype fuigo (鞴) box bellows...two intake valves, two manifold valves, one piston, one output, double action...more about fuigo here: http://islandblacksmith.ca/2015/06/why-you-need-a-swordsmiths-fuigo-box-bellows/
valves: http://islandblacksmith.ca/2015/11/making-valves-for-fuigo-box-bellows/
fuigo archive: http://islandblacksmith.ca/tag/fuigo/