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In use, the unique, flexible construction of this brush-hone makes the tool both self-centering and self-adjusting to compensate for any wear. In accordance with the abrasive type and grit size, precise surface finishes ranging from mirror finishes to cross-hatching are automatically accomplished. “After we decided to test the brush-hone, BRM gave us some recommendations and basic guidelines,” recalls Taylor.

BRM developed a series of fine grit models for die applications where RCBS used progressively finer grits to achieve their results. “I had a spare CNC mill, so I made up a fixture and started trying the process at different speeds and feeds. It took several process changes before we were able to consistently achieve our stringent surface finish requirements.

Initially, Taylor wrote a very basic honing program for the CNC mill. Once he decided to go online with the process, he wrote a parametric program to automate the process. Essentially, the CNC operator inputs four or five different parameters, e.g. bore length and ID. The CNC performs the necessary calculations, and then selects the corresponding Flex-Hone brush. Based on the input, the CNC also calculates the number of tool strokes, rpm, and so on.

“The new automated process is a real game changer,” Taylor says. “It is probably 60 percent to 70 percent more efficient than doing it by hand. Also, there was a substantial increase in quality. It is better and faster. But the ergonomic improvement – removing the potential for operator discomfort and injury – alone would have been enough to justify the new process. For instance, there are no more repetitive motion injuries because there is no more repetitive motion in the polishing. So, that is a 100 percent improvement.”

Taylor says that the surface finish of the RCBS steel dies is now sub-micron (roughness value) when they come off the machine. After the Flex-Hone finishing operation, the surface finish is improved by a factor of eight. He adds that “depending on the die, we use multiple hone sizes as well as varying grit materials and number of strokes.”

With the steel die finishing solution a success, RCBS decided to try the flexible hone solution on its dies that feature a much harder carbide material. “On those we use a unique Flex-Hone brush with diamond crystal grit, and basically achieve the same type of results in terms of automation and finish,” Taylor says. “The finish looks like a mirror when we’re done.”

For more information, contact Brush Research Mfg. Co., Inc., 4642 East Floral Drive, Los Angeles, CA 90022, 323-261-2193, Fax: 323-268-6587, www.brushresearch.com.

ATK Security & Sporting Group, 7480 Flying Cloud Drive, Minneapolis, MN 55344, 952-351-3000, www.atk.com.