You have reminded me of a summer working in a pharmaceutical company as a student. There was a fun machine for pulverising sugar, a tonne at a time. On the gearbox was a big lever labelled “knives forward” and “knives backward”. The entire room was explosion proof because fine sugar dust in the air makes a nice barothermic bomb.
When I got back to U, I thought I would take a look in the library for information about this machine. Sure enough, there was a fat textbook, from the 1930s, about the technology of rotary pulverising machines.
The differential equations started on about page 30 and continued for several hundred more pages. Not something you knock up in an hour or two with a 3D printer.
