Originally, 3D printers were invented to fill the needs of manufacturers' R&D departments. The traditional cycle of design, machine by hand, and test -- again and again -- was time consuming and expensive. The movement to outsource machining capability to China has simply drawn out the time delay associated with this cycle. By making the manufacture of test pieces automatic and hands-off, 3D printers result in a much more agile prototying process.
Increasingly, 3D printers are being used for full-time manufacturing. 3D printing turns the mass-production paradigm on its head: Instead of high startup costs and low unit costs once you reach high volume, startup costs are low and the incremental cost for each item you make is the same as that of the first one. Generally, the point where mass production becomes cheaper per unit than 3D printing falls between 10,000 and 100,000 units. In fact, 3D printing can be a less expensive solution for a significant segment of the manufacturing market.
Today, there are dozens of companies vying in the personal 3D printer market. This includes such proprietary commercial players as MakerBot, Stratasys, and 3D Systems, as well as open source upstarts such as Ultimaker and the venerable Reprap project, the granddaddy of the open source 3D printing market.
Printers printing printersTen years ago, open source 3D printers did not exist. You could buy a commercial machine for $20,000 and order the stock material from the manufacturer. Then, in 2007, the original patents on many of those machines expired.
In the spring of 2007, the first open source 3D printer came online at the University of Bath in the United Kingdom. This machine, composed largely of parts produced by a commercial printer, plus a few motors and circuit boards, was capable of manufacturing most of its own components. In 2008, the first fully self-replicating rapid prototyping machine, called the RepRap, was made of parts printed by another RepRap. It was open source hardware in the purest sense: Feed the open source design to a 3D printer and out pop the parts to assemble another.