I’ve already said how much I appreciate Zaggo’s designs.  Watching his treasure chest being built on my ‘bot was really really cool.  The hinge pins were printed already inside of the hinge – something made possible by the nature of fused deposition modeling.

While this toy car by kparanya was probably the first captive breakaway multipart print I’ve seen on Thingiverse, I was more inspired by Zaggo’s treasure chest.  :)  It should be possible to print entire geared assemblies using this kind of system.  Admittedly, you’re probably not going to get precision geared parts, but you could probably make a decent toy or rough tool.  Once you start using the piece it should essentially grind out any extra plastic threads.

Anyhow, something to think about.