Genkei is comapny from Japan that produces 3d printers. They made this enormous 4 meter tall Delta 3d printer. I think it is not designed to be real production printer, but more of a demonstration and promotional project.
It will use pelleted material for extrusion instead of filament. It makes perfect sense for this size of machine.
The 3d printer will be on display at the Tokyo National University of Fine Arts and Music Museum, as part of an “Materializing II” exhibition that runs from Saturday, July 19 until Friday, August 8.
Genkei homepage: http://genkei.jp/
Source: http://3dprint.com/8835/japan-huge-delta-3d-printer/
Update:
here is the video of Magna in action:
Update:
USA based SeeMeCNC is presenting their even bigger Delta, so the race for the largest Delta is ON:
http://diy3dprinting.blogspot.com/2014/07/seemecnc-partdaddy-45-meter-tall-pellet.html