I need someone to explain this to me.

Printing a RepRap

repstrap

The RepRap project has been working on bringing 3D printing to the masses by creating a extrusion printer that can also make the majority of its own parts. For the most part, these print ABS or HDPE plastics which are strong and recyclable. In order to create these replicating printers, similar machines called RepStraps are built out of either laser-cut parts or machined elements. They are functionally equivalent to RepRap printers, but are not made of printed parts. [nophead] documented his RepStrap, HydraRaptor, that is based off a milling machine. He had already printed a set of RepRap parts, and he documented printing a second set. The machine worked for about 100 hours over the course of 2 weeks, printing about 1.5 kg of parts. He made a few adjustments, such as replacing ABS bearings with HDPE to reduce friction. The parts are for Factor e Farm so they can get started with 3D printing.

Related: RepRap pinch wheel extruder