I recently got into “Karakuri” paper models. It is a pretty eco-friendly and cheap hobby, especially if I use paper/ads from the mail.
Karakuri puppets are traditional Japanese mechanized puppets or automata-for-fun. It became a thing in Japan after Europeans introduced clocks. I imagine the first Japanese engineer or person who opened a clock to see what's inside, saw all those cams and gears, and of course thought of making something way more funny ;p
I got this book from amazon.
The book has really good explanations of the science and physics/movements. It is not just a “follow these directions” kind of book. It also shows some projects done by high-school students and gives you tips for what to use (type of glue, matt, etc…)
There are also some models to cut out and assemble. I already made two. I think the cutest so far is the peek-a-boo bear.
Here is what is inside:
Adding a PI / montion sensor
I could add a little raspberry pi. An idea is to add a motion sensor inside. Once you get close to the bear, the cams will rotate and the bear will do a peek-a-boo. I can connect the paper model to a bell and put it on the door. Once someone gets close to the door/teddy bear, it can ring a bell or send a notification to my phone ;p (so the person doesn't have to press a physical button – that is so pre-covid). Of course the teddy bear can be dressed differently in the summer or winter ;p
But I kinda enjoyed building something without using computers. So, it might be a while before I add more automata.