This is just over the top geeky.
The Making of A 3D Printer
Ever wondered how a 3D printer actually works, or thought about building one from a kit? These step-by-step photos show how to start with a collection of parts and end with a finished printer.
via The Making of A 3D Printer | PCMag.com.
On the other hand this is good to know. This is the kind of technology behind some of the digital model systems. In fact we may be using a 3D printer to make crowns bridges and dentures in the not to distant future.