contraption (noun)
: a machine or device that appears strange or unnecessarily complicated, and often badly made or unsafe (Oxford Languages)
: a device or machine that looks awkward or old-fashioned, especially one that you do not know how to use (Cambridge Dictionary)
: a usually mechanical or electronic device or gadget (Merriam-Webster)
A Rube Goldberg machine, named after American cartoonist Rube Goldberg, is a chain reaction–type machine or contraption intentionally designed to perform a simple task in an indirect and (impractically) overly complicated way. Usually, these machines consist of a series of simple unrelated devices; the action of each triggers the initiation of the next, eventually resulting in achieving a stated goal.