Think ahead to the near future. You’re shopping on eBay, and see a cool pair of sunglasses. So you buy them. But you don’t enter your shipping information. Instead, you just hit Print. A few minutes later, your printer spits out sunglasses. It’s not a picture. It’s the actual pair of sunglasses.

Your home printer just fabricated your purchase. The process is known as Rapid Prototyping. It’s the ability to print complicated 3D objects. The machines to do this can cost upward of $150,000.

But a group of graduate students built a 3D printer for about $3,500. You can learn more at Fab@Home.org.