Sublime (Brad) at Tantillus.org printed a fully functional hobby lathe using PLA plastic capable of cutting metal parts. Each of the parts necessary to build the lathe was small enough that they could be produced on an affordable 3D printer within the budget of most robot hobbyists.
The lathe design was the result of contributions from many people, though Sublime added his own touches/improvements. The surprising thing for me was that it is definitely possible to bootstrap from a low-cost 3D printer to create other tools that most robot hobbyists want for their home workshops.
I'll be posting more about Sublime's work and the creation of the Tantillus 3D printer in subsequent videos.