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82 MMS April 2017 mmsonline.com FEATURE quite another. Complicating things even further, parts had to be separated again after the grind for final inspection. As in any complex automation project, design- ing a cell to grind and inspect thousands of components per day and millions per year required a great deal of thought, effort, and close, con- tinuous collaboration with the customer. In this case, par ts emerge complete and drop into a box, ready for shipping. No human intervention is required beyond basic maintenance and keep- ing the cell fed with work. As for qualit y and consistency, a process capability rating of 1.7 Cpk provides the customer (as well as the cus- tomer's customer) with confidence that ever y part is defect-free and produced according to specifications. SETTING THE PACE The single point of monitoring and control for the entire cell is the grinder's Beckhof f CX Series motion controller and touchscreen human-machine interface (HMI), which uses Glebar's own front- end software to interface with all servos, gages, programmable logic controllers (PLCs) and other vital organs of automation. Yet, there's a mechan- ical control on this cell, too, one that Mr. Bannayan calls the "pace car" for the entire process: the precision singulation system located immediately before the grinder. Although this system is the primary constraint on production, it is necessary because the tiny parts are bulk-loaded. The journey begins in a vibratory-bowl feeder that funnels the parts onto a conveyor belt. From there, they move single-file down a narrow trench in a continuous, unbroken stream, the back end of one nestling into the open front end of another. Left this way, they'd be impossible to differentiate from one another during laser and high-speed camera inspections that determine whether they're suitable for grind- ing in the first place. "If you have any ovality in that pa r t at all, it's going to bounc e a round between the two grinding wheels," Mr. Bannayan says about the laser system. "It's either going to be out of tolerance or it's going to crack or break." As for the high-speed cameras, "chips Parts begin their journey in a vibratory bowl feeder (1), then pass through a singulation system (2) and laser and camera inspections (3 and 4) prior to grind- ing (5). After cleaning (6), they move through another laser diameter inspection (7) that feeds back to the grinder to keep machining on track. A step feed conveyor carries the work to a second vibratory-bowl feeder (8) that feeds parts into two channels. Each stream is broken up again for individual inspections on an eddy current sensor, and good parts drop into a box for shipping (9 & 10).