RefreshEng and NUM technology breathe new life into Cincinnati 2-OM centreless grinders

Controlled by NUM's Flexium CNC kernel, the upgrade solution converts any of the veteran Cincinnati 2-OM family of centreless grinders to the same kind of automated and precision machining available on state-of-the-art grinders - but for an outlay that is some 60% lower than a new machine, it is claimed. Initially, the new NUM CNC based machine is targeted at centreless grinding applications in the aerospace industry, and comes with application-specific software to automate the production of the specialist countersink, button-head and relief style fasteners used in aviation fuselage and engine production. RefreshEng's CNC upgrade solution is offered in four variants, with a choice of three autoloading options. The NUM-based upgrades transform the Cincinnati 2-OM's original hydraulic- and mechanical-dressing architecture - with its fixed cam-and-stylus control - to an advanced CNC software-based system with up to seven axes of servomotor-based motion depending on customer choices. NUM's operating software employs dialog boxes to simplify programming - allowing new grinding profiles to be created in less than a minute. The operator simply populates data fields on a sequence of screens, which include graphical representations of the fastener style selected, and the profile is automatically generated. Parts can then be produced completely automatically, with the machine's software also automatically performing housekeeping tasks such as dressing the wheel. The hardware upgrade is based on NUM's economic Flexium 68 CNC kernel, with an FS152i touch-screen HMI, machine panel with handwheel for operator programming and control, plus MDLU3 drives and BPX servomotors fitted with precision absolute encoders. The seven axes controlled by the CNC, depending on the machine model, are control wheel-infeed, -traverse and -rotation, dresser-infeed and -traverse, backstop and spindle lateral adjust. "The Flexium upgrade we've devised provides an economic CNC solution that brings the workhorse 2-OM range of machines bang up to date, in terms of precision, programming flexibility and automation - boosting productivity substantially," says Damian Clements, CEO of RefreshEng. "Capital investment cost is reduced by such a large margin, compared with a new machine, that payback can be as short as a few months - which is critical for many of the manufacturers in this highly competitive sector. The new machine also automates all aspects of the centreless grinding process, eliminating any need for manual interventions such as loading and hand finishing, to deliver a much higher level of safety."