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Issue link: https://mms.epubxp.com/i/155490
feature parts into the machine tools using an overhead crane. Once company managers recognized they couldn't fill their skilled labor capacity need through hiring, they determined to free up their existing labor capacity by automating steps such as this one. But what was the right way to automate? The company knew of no other shops in its region or in its market that were applying robotic automation. Even Mr. Campbell, who was hired by Stabiltec because of his manufacturing experience in industries outside of oil and gas, says robotic automation was not his first choice. Reasons foR a Robotic cell Though the transmission parts vary considerably from customer to customer, what they all have in common is some combination of turning, milling and drilling. For this reason, Mr. Campbell initially thought that multitasking would be the right way to achieve more labor-efficient machining. Previously, machining each part had involved operations on both a lathe and a machining center. Switching to a machine able to do turning, milling and drilling in one cycle would leave just one machine tool into which to load the part. The operator's role would therefore be reduced. However, closer analysis revealed that multitasking was not the ideal solution for this application. One shortcoming was cost. Because of through-hole drilling and boring operations, the machine would need to have long travels to accommodate long tools. One multitasking machine big enough to do the job would cost the same as the combined price Stabiltec ultimately paid for the robot, lathe and machining center that now do this work. Another shortcoming was throughput. The multitasking machine could either turn a workpiece or mill it, but it could not do both operations at once. Allowing the work to remain split between a lathe and a machining center would be more productive, because the machines could perform these operations simultaneously on different pieces. Repeatable robot loading would remove the risk of handling or setup errors typical of processes involving multiple machines. The final argument in favor of a robotic cell came back to labor capacity. A multitasking machine would reduce the need for labor, but Mr. Campbell still envisioned an operator loading it. By contrast, the robotic cell would enable the shop to do away with labor for long stretches of time in machining the transmission components. Now, these parts are run in a cell in which a FANUC Robotics R-2000iB robot with a capacity of 165 kilograms loads and unloads both a Mighty USA Viper VT36CL-2000 CNC lathe and a Haas VF-5XT vertical machining center. The company justified the entire cell on the basis of freeing up operators during the day and continuing production into the night. Once the cell was A typical transmission consists of three machined components, as seen in the photo of assembled transmissions at left. The parts are ordered in quantities that could be as small as 10, so the robot is used for high-mix, low-volume production. Repetitive high-volume work is not essential for automation to succeed. mmsonline.com September 2013 MMS 69