There’s a whole genre of creation that is basically just engineers tinkering to make cute mechanical structures. Historically you’d see odd whittled wood mechanisms and such, but with the proliferation of 3d printers, that hobby has exploded.
One of my favorite creators in this Genre is JBV Creative. He simply applies complex mechanical engineering to 3d printed kinetic sculptures, and most importantly shares his process.
The sculpture above is a fantastic example. Not only do you get this satisfying kinetic sculpture in the end, you also get to follow along as different mechanisms and geometry are tested to get the wanted result.
You can pick up all kinds of useful tidbits of engineering from watching these videos. I highly recommend you go check out the whole channel, there are many videos there to learn from.
Some videos focus more on the engineering process, like the one above. I really like how much JBV tries to pass on his knowledge and processes to help other people create things like this.