Open source hardware and 3D printers go together like, well, open source hardware and 3D printers. Not only are 3D printers used to create all sorts of open source hardware—there are also a huge number of 3D printers that have been certified as open source by the Open Source Hardware Association. That fact means that they are freely available to improve and build upon.

Source: LXer – 5 notable open source 3D printers