APEX series showing how to rig mechanical systems like pistons, suspensions with springs (motorcycle or car shock for example), ball joints with constraint movement (think how steering works on a car). I think the best way to approach this is to showcase it in a style of a LEGO model, its very visual and relatable. A lot of reference can be found on youtube as well. Things like this for example:
https://www.youtube.com/@in1
Starting with simple systems and gradually getting into more advanced ones.