[wakeupcall]

I also find that line hilarious, but maybe it's intended as in "size adjustable down to the millimeter".

CAD programs are generally unitless. You can design a box with OpenSCAD "down to a micrometer" if you want.

Designing a joint that works well also will poorly 3d-printed parts is usually what matters, but it's not like we're lacking customizable solutions:

https://www.printables.com/model/757297

(not detracting from the website.. just commenting on the headline)

[sahruum9]

The STL format is unitless, as is OpenSCAD, but the vast majority of CAD software uses units.