u/ginhinio

This is a twist-to-zoom lens barrel: 6 parts, clear PETG on a P1S. Twist the outer ring and a hidden helix inside pushes the barrel out.

I didn't model it in CAD. I described it: "I want a camera lens mechanism that you twist to extend or retract." Then I kept asking for changes in plain English: make it print without supports, make the pieces click together, hide the sliding mechanism. It took about 14 rounds of that back and forth, not one magic prompt.

Full disclosure: the tool is mine. It's called Loftsmith, and I've been building it because I wanted something like a friend who's good at CAD. You say what you need, it writes real parametric CAD (not a mesh), and you can keep refining it in plain words.