Meccano can be used to build gearboxes and differential transmission.
This guy had made a knitting machine.
Electronics is creeping in, this machine had an Arduino at the core of it with a fantastic relay board running everything.
I remember using one of these Philips electronics kits as a child.
Circuits were built to a template with components joined with little spring things.
This electronically controlled car had everything including electric windows.
A two story elevator with doors and interlocks was built by a retired lift mechanic!
Here's Mal learning about steam engine control from a fellow amateur.