Piano Roll Reader
This is a pneumatic vacuum-powered reader for old-fashioned paper player piano rolls. (See 1st image)
Certainly there is a musical use for this, but I had other purposes in mind when I came up with it.
Specifically, I designed this for the purpose of being able to "program" pneumatic machinery.
More details available on my projects blog, here:
https://theheadlesssourceman.wordpress.com/2018/06/22/piano-roll-reader/
NOTE: The customizer may be of questionable usefulness. It could be fun to fiddle with, but to do any real work, I recommend downloading the openscad file.