Since one of the design ideas behind this machine is to make it widely available, the material it uses had to be widely available and cheap so the main material is molten aluminum wire.
While the basic technology sounds easy in theory and has been used even 20 years ago in the past for some applications, there are still many difficult technical obstacles to overcome. These obstacles include reaching complex requirements like developing a printhead that is resistant to abrasive properties of molten aluminum by using ceramics, magnetic containment and getting drop-on-demand molten metal droplets.
The price range of the first machine should be around 250.000 USD which is much cheaper than currently available commercial metal 3d printers.
Hopefully the Vader team will be successful in bringing their machine to the market and start the race for affordable HOME metal 3d printers. I want one! And I know some of you want one too
Vader Systems company page: http://www.vadersystems.com/