1989 - Large segmented mirror arrays are built in jigsaw fashion from many non rotationally symmetric parts. These glass structures, figured on the off-axis grinding machine, are shaped assymetrically up to 2.5m square by 800mm deep. The machine weighs 130 tonnes and incorporates 9 axes of laser interferometry at 2.5nm linear resolution. A metrology frame based on three Zerodur straight edges eliminates errors caused by heavy moving carriages. The OAGM 2500, the largest ultra-precision grinding machine ever built, remains in full production at Kodak Federal Systems Division, Rochester, NY, USA.
1991 - The Nanocentre was, in its time, the most accurate machine tool of its size ever built: Major features are: Granitan structure, hydrostatic linear and rotary axes bearings, laser interferometry resolving position to 1.25nm, built in refractometry, multi-axis synchronised moves using the CNC3200, 32 bit microporcessor controller, friction driven X and Z axes, automatic CNC tool setting to 5nm repeatability with an optical tool setting system; temperature control to all liquid systems to within ±0.01°C. The machine can be changed from diamond turning to state of the art shear mode grinding of optical components in a few hours.« Back Next »