US boffins have invented a reasonably cheap 3D printer that can make metal tools and components.
Developed by a team at the Michigan Technological University, the printer can be created with parts that cost less than $1,500.
The team, led by associate professor Joshua Pearce, has developed the software and firmware used to control the printer and made plans to construct it freely available to anyone.
Pearce said the printer is a work in progress with parts created by the machine no more complex than a sprocket.
"Similar to the incredible churn in innovation witnessed with open-sourcing of the first RepRap plastic 3D printers, I anticipate rapid progress when the maker community gets their hands on it," said Pearce. "Within a month, somebody will make one that's better than ours, I guarantee it."
The parts to make the 3D printer include a small commercial MIG welder and an open source microcontroller. The machine can lay down thin layers of steel to form complex geometric objects. Commercial metal printers are available, but they cost over half a million dollars.
Pearce said the DIY metal printer is less expensive than off-the-shelf commercial plastic 3D printers and is affordable enough for home use. He suggested the device would be better off in the hands of skilled personnel for the moment as it requires more safety gear and fire protection equipment than the typical plastic 3D printer.
The invention raises the possibility of someone using the 3D printer to make their own firearms. However, Pearce said he believed the good to come from all types of distributed manufacturing with 3D printing will far outweigh the dangers.
The device could benefit developing countries that have limited access to manufactured goods, he said, and researchers who can radically cut the costs of scientific equipment to further their science.
"Small and medium-sized enterprises would be able to build parts and equipment quickly and easily using downloadable, free and open source designs, which could revolutionise the economy for the benefit of the many," said Pearce.
However, he cautioned that society may not be ready or mature enough to handle the prospect of readily-available, cheaply produced goods the printer could herald.
But added that with an open-source approach, "we are within reach of a Star Trek-like, post-scarcity society, in which 'replicators' can create a vast array of objects on demand, resulting in wealth for everyone at very little cost. Pretty soon, we'll be able to make almost anything."
