This is important step forward for the entire field: open source sub 1500 USD metal printer. It can be mad by anyone with some experience. It is based on static MIG welder and moving invert delta 3d printer platform as build bed.
Project was developed by Michigan Tech's Open Sustainability Technology Lab: Gerald C. Anzalone, Chenlong Zhang, Bas Wijnen, Paul G. Sanders and Joshua M. Pearce. Kudos to you gentlemen!
From project abstract:
Technical progress in the open-source self replicating rapid prototyper (RepRap) community has enabled a distributed form of additive manufacturing to expand rapidly using polymer-based materials. However, the lack of an open-source metal alternative and the high capital costs and slow throughput of proprietary commercialized metal 3-D printers has severely restricted their deployment. The applications of commercialized metal 3-D printers are limited to only rapid prototyping and expensive finished products. This severely restricts the access of the technology for small and medium enterprises, the developing world and for use in laboratories. This paper reports on the development of a <$2000 open-source metal 3-D printer. The metal 3-D printer is controlled with an open-source micro-controller and is a combination of a low-cost commercial gas-metal arc welder and a derivative of the Rostock, a deltabot RepRap. The bill of materials, electrical and mechanical design schematics, and basic construction and operating procedures are provided. A preliminary technical analysis of the properties of the 3-D printer and the resultant steel products are performed. The results of printing customized functional metal parts are discussed and conclusions are drawn about the potential for the technology and the future work necessary for the mass distribution of this technology.
Project homepage with detailed build instructions:
Academia paper on this printer:
If you want to learn more about MIG (metal inert gas) welding:
There is another welder based DIY metal 3d printer project with almost no documentation - The Chipfuzer:
New TIG welder based metal printer: