http://makezine.com/projects/the-multim ... milldrill/
3D printer my ass.You just need a metalworking lathe. Metalworking lathes are necessary to the production of almost everything but are very expensive. In 1915, special lathes made from concrete were developed to quickly and cheaply produce millions of cannon shells needed for World War I. Lucien Yeomans, the inventor, won the nation’s highest engineering award for it but sadly the technique was almost forgotten after the war. We re-discovered it as a way to quickly make inexpensive but accurate machine tools for use in developing countries and in trade schools and shops everywhere. We made modern construction practical by replacing the original poured, non shrinking metal with cement grout.