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86 MMS April 2017 mmsonline.com FEATURE Diameter adjustments are plotted in a line graph on the HMI for easy viewing. If the readings trend too far from nominal, the cell stops. With a single scoop, a diverter arm removes not just the offend- ing part (which can't be reliably identified at such high speed), but also ever y par t in the stream leading back to the grinder. Once parts are cleared out of the cell, manual inspections weed out any that are truly out of specification, and the opera- tion can continue, defect-free, once the problem can be identified and solved. The primary challenge in setting up this system was balancing the need to avoid faulty parts and keep the cell running with minimum stoppage, Mr. Bannayan says. A data filter that's too strict would lead to frequent and unnecessary interrup- tions, and a filter that's too lenient would lead to unnecessary risk. Fine-tuning was critical, par- ticularly with a system sensitive enough to pick up contaminants as seemingly insignificant as a drop of coolant. This is also why parts pass through an air-knife cleaning station immediately prior to the laser inspection. FULL AUTOMATION, ZERO DEFECTS Any faulty part that makes it through the second laser diameter gage is caught and diverted at the next inspection station. A step conveyor carries parts to a second vibratory bowl feeder that fun- nels them into an eddy current sensor. Commonly used and specifically suggested by the customer as a means of quality control, these devices use electromagnetic fields within the part to detect cracks, voids or other imperfections. Two of these devices must operate simultane- ously to keep up with the two-part-per-second production rate. To that end, the vibratory bowl feeds parts into two channels, each with a cir- cular cartridge at the end that stops the flow of parts. These cartridges index at a precisely timed rate, with each movement allowing a single part to fit snugly into one of the slots carved into its outer diameter. At the same time, a pneumatic tube opposite the feed sucks another part from its cartridge slot and directs it down a tube into the waiting eddy current sensor. Rejects are diverted, and good parts drop directly into a box. When the count of good parts matches the batch size of 10,000, the first box is conveyed out of the cell for shipping, and a new one shuttles in automatically. For the customer, the new cell will mean no more manually pushing every part through eddy current and laser inspection to weed out rejects, no more manual boxing (or re-boxing) prior to shipping, and perhaps most importantly, no more surprises or emergencies. For anyone else, this project demonstrates not only the possibilities of modern automation systems, but also the hard work, creativity and expertise they require, even if the specifics of this project are unique to a particular supplier and customer. The grinding, inspection and packaging cell is capable of churning out millions of zero-defect parts per year. Glebar, call 201-337-1500 or visit glebar.com.