Developments in cellular manufacturing are emerging as key trendsetters.
“Cells are increasingly compelling as a strategy for round-the-clock productivity.”
Modern Machine Shop, Mark Albert,
Mark: My Word (A monthly column of comments and opinions)
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Mark has been writing his Mark: My Word column every month since January, 1981.
I visited a fair number of booths at the 2011 EMO tradeshow in Germany, but the one that gave me the most food for thought was that of a factory automation supplier. Fastems, headquartered in Finland, is best known in the United States for its robotic machining cells, pallet magazines and flexible production systems. To ensure the success of a cell, which depends largely on the control system, the company also develops software. As shops move to cellular manufacturing, developments in cell control capability indicate important trends in production concepts. This was apparent at the booth.
One of these trends is morphing cell control into the basis for a shop-wide production control system. This is the point of the company’s multi-level manufacturing management system. On one level, the software acts as a coordinator of the cell’s activity by routing the pallet transporter to available machines, keeping track of incoming and outgoing workpieces, monitoring status of both machines and work-in-process, and other functions. What’s new is that the same system can also manage the production schedule as well as organize the library of NC programs and the database of cutting tool information.
On another level, that of the “station commander,” the system provides the human/machine interface (HMI) that runs on a Web browser so that the cell is accessible remotely to any Web-enabled device for monitoring. Finally, a “dashboard” utility enables cell status to be displayed on a large-screen monitor, thus giving visibility to shop personnel.
Another trend is the melding of lean manufacturing principles into cell design. The automated cell is the ultimate in flexible, zero-setup, order-based production. Flexibility, in this context, represents the open-ended opportunity to continually find waste-reduction adjustments. This principle was best exemplified by robotic deburring on a machining cell set up in the booth.
The robot was doing double duty. Its main role was to handle workpieces at the load/unload station. Its secondary role was to deburr parts between machining operations. This required the robot to exchange its part gripper for a rotary deburring tool. Manipulating this tool made good use of the robot’s multi-axis dexterity. It also kept one of the machining centers from sacrificing its metal removal capacity for a secondary operation. In addition, deburring gave the robot a productive task to do during the otherwise idle time while the machines were in cycle, so the gain was almost a “freebie” in terms of resource utilization.
Because one of the advantages of a cell is the ability to produce a variety of dissimilar parts, programming a robot for numerous complex deburring routines could be an obstacle. However, this barrier has been lowered by the company’s new Fastsimu offline programming software, which automatically creates a deburring routine, using a CAD file as input.
Although cellular technology is by nature hardware-intensive (a lot of racks and rails and pallets), advances on the control side make cells increasingly compelling as a strategy for round-the-clock productivity. The key lies in the potential for integrated manufacturing data management.