.....if we replace the throwing arm of : www.ronleigh.com/ivytech/_ref-trebuchet-range.htm (http://www.ronleigh.com/ivytech/_ref-trebuchet-range.htm)
...with a single simple hinged arm of a "classical" design (see Middle Ages wheels...) at :
https://www.lhup.edu/~dsimanek/museum/machines/perp_ani.gif (https://www.lhup.edu/~dsimanek/museum/machines/perp_ani.gif)
A trebuchet ( gravity simple machine...variable lever ) modified into a gravity self-powered simple machine (oscillatory lever...) ?
If so , there is nothing new (a kind of "Lego-soft",only)...but the gratitude to our predecessors.
Al_ex