Using of 3D Printers When I was searching on the Internet, I found many uses of 3D printers. Some of this uses are dangerous. They could print a complete weapon such as Knifes or guns. I am afraid, If the government consider that printers as a dangerous machine. On the other hand, they could print very useful things. I found in the Internet that the scientists fabricated a very small battery that I can use in Laptop or mobile phone by using this printer. I watch a news report on Fox News that a Father built prosthesis for his child and it cost only ten dollars. This is the link of this report (http://goo.gl/WDirft ).