[crooked-v]

Lego Mindstorms could be worth considering as a general-purpose hobby robotics platform: EV3 (the older version) can be flashed with a custom Linux distro, and Robot Inventor (the newer one) can run Python scripts. In either case all you need to add more structural parts is to pick up a bulk case of used Technic parts, so it's eminently reusable for multiple unrelated projects.

For an example of stuff people have built with them, here's a Robot Inventor-based Rubik's cube solver: https://www.youtube.com/watch?v=_cl2Wur8waY

[monocasa]

Oh jeeze, I feel old if the EV3 is being described as "the older one". I have horrible memories of writing some "Not Quite C" for RCX because the compiler didn't support modern amenities like stack frames.

Being able to just run Linux on the thing sounds like a god send.

[wcarss]

A group I worked with in a high school lego robotics competition managed, if I recall correctly, to achieve 'recursion' by defining 2 very similar functions and having them just call each other. It was a frustrating device at times but also a really fun experience!

[cema]

Is called a trampoline, a standard trick more or less.

[wcarss]

Cool! That makes sense -- it still felt incredibly clever and tricksy to us when we were about 16 and trying to map our 'beautiful algorithm' into NQC sometime past midnight, for a morning competition.