Accura Ships 0.15 micron Bearing Grinder(Pic)

Accura Technics Inc. (USA, privately held)[website] announced it has shipped a bearing grinder repeating 0.15 micron roundness. The company's 1210G multi-surface grinder is being used to finish spindle components for camshaft and crankshaft roundness measuring equipment. Roundness in pre-delivery tests achieved 0.15 micron for a ball bearing inner race, and 0.25 micron for a ball bearing outer race. The grinder X-axis has a hydrostatic bearing workhead driven by a linear motor. The other two axes are an air bearing ID/OD spindle wheelhead and a ball bearing rotary surface spindle wheelhead. The wheelheads are independently CNC controlled, using servomotor ball screws. The entire assembly is mounted on a thermally stable natural granite base. The grinder allows workpieces up to 250mm tall, offers a 300mm swing, and 350mm X-axis travel. A variety of options are available such as autoloaders and gauging