Agreed, this is some proper nice tinkering writeup that we get far too rarely now.

Lovely project! I'm a software guy who in recent years does lots of CAD for hobby projects (mainly robotics) and orders custom machined parts (lots of sheet metal construction, occasionally milled parts) along with 3D printing.

I find parametric modelling very zen. Stacking operations is very Lego-like, like stringing up pure functions. Plus I can listen to podcasts while I model, but not while I write code - it engages the brain differently.

Now that LLMs are sapping some of the joy out of programming (I use the tools, they're productive, achieving goals and delivering user value is still satisfying, etc. - but the act of writing code is just more enjoyable than prompting, so it's a tad dispiriting that it's getting harder to jusitify) I also find that I get a lot of satisfaction from doing something with my hands. In some ways it's a safer space for technical creativity.

Can highly recommend hobbies like this.