We report on the first-ever demonstration of grinding and polishing full-size, off-axis aspheric, mirror segments as
prototypes for an extremely large telescope, processed entirely in the final hexagonal shape. We first describe the overall
strategy for controlling form and mid spatial frequencies, at levels in the vicinity of <10nm RMS surface. This relies first
on direct CNC grinding of the base-form of these 1.4m segments, using the Cranfield BoX™ machine. The segments are
then mounted on a custom designed (Optic Glyndwr Optoelectronic Engineering Group) three segment hydraulic
support, and CNC polished on a Zeeko IRP 1600 machine using a variety of custom tooling. We overview the fullaperture
and sub-aperture metrology techniques used to close the process-loop and certify quality, all of which operate
with the segment in-situ on the IRP1600. We then focus on the pristine edge-definition achieved by the combination of
tool-lift and smoothing operations; results never previously demonstrated on full-size pre-cut hexagonal segments.
Finally, the paper discusses the feasibility of scaling the process to deliver 931 segments in seven years, as required for
the E-ELT project.