Okamoto technology delivers new orders of flatness

Flatness and straightness levels within 0.5 micron can now be held per metre stroke of the machine table in the latest Okamoto UPG-84NC Ultra Planarisation surface grinder while supporting table loads up to 700 kg. The machine has a table size of 850 by 400 mm and an electro-permanent magnetic chuck size of 800 by 400 by 100 mm. Grinding wheel size is 305 by 38 by 127 mm driven by a 5.5 kW motor and distance between wheel and table surface is between 50 and 550 mm. The x-axis longitudinal table speed is variable between 0.3 and 25 m/min, vertical and cross-feed rate is between 1 and 790 mm/min. The UPG-84NC is the most compact of the latest UPG machine range of 13 machines which can be specified having table lengths up to 4,000 mm and all are capable of generating the same degree of flatness. Okamoto achieves this performance by having added programmable variable pressure to hydrostatic bearing technology which enables some four times greater levels of rigidity to be obtained over conventional surface grinding machines that use hydrostatic bearings. The technology was originally developed by Okamoto’s special purpose application engineering team to create a new order of ”mother” machine capability with minimum inertia and vibration when the table reverses. The idea was to create new orders of flatness and straightness for production grinding its own surface grinding machine tables, beds and bearing guide rails. The latest UPG range is ideal for grinding tasks such as dies, master granite surface plates, metrology equipment, LCD and semiconductor production. All the machines in the range have been completely re-designed using totally enclosed stainless steel guarding giving easy access to the grinding area.