Do you know a software tool that cuts a bigger .STL object into smaller .STL objects and take the smaller .STL objects and add joinery to it, so they lock together once fully printed.
Not .STL, but http://www.tamasoft.co.jp/pepakura-en/ is a simple algorithm that converts most common model files to a foldable structure. (It’s also available on the bay)
You could probably do multiple exports/imports or mod their code and finish with a .STL closer to what you’re wanting.
EDIT; Turns out this program does work with .STL format, they’ve updated since I last used it.
please don’t pirate Pepikura. It’s only $29 and it’s maintained by an origami master. It’s a great value.