Building a 3D printer from a kit takes the mystery out of the technology. This one is called a RepRep Prusa Mendel 2, because it’s self replicating. Once you’ve got one you can print the custom parts on the 3D printer and all the rest is made from off-the-shelf components. The printer uses PLA, a plastic made from cornstarch and has a faint smell like candyfloss when it’s printing.
When I made this 3D printer, I didn’t like the shape of it with all the exposed wires. But once it starts working, it’s quite mesmerising.