INCREASING SPEED AND EFFICIENCY WITH AUTOMATION When you compare one saw to another, what do you notice? Most fabricators point to cutting time as the most significant point of difference, and that difference raises important questions about throughput and ultimately, efficiency and profitability. Over the past 50 years or so, saw manufacturers have come a long way. Today's circular and band saws have little in common with early reciprocating power hacksaws with ratchet feed. Up-to-date production saws with frequency-controlled feeds and speeds are modern machine tools. While in the early days the saw blade was the limiting factor for a machine's performance, today's machines use carbide cutting tools and outperform their predecessors many times over. Modern design elements - ball lead screws, linear guides, and composite materials, just to name a few - together with the latest CNCs and programmable logic controllers allow not only a much larger variety of material grades and shapes to be cut, but the saws can cut these jobs efficiently, precisely, and consistently. With the advent of flexible manufacturing, mass production is becoming less and less necessary. As the need for flexibility increases, the need for high production volume decreases. Subsequently, the saw, normally the first machine in the manufacturing process chain, has to be able to cut small quantities - even one-of-a-kind items - as efficiently and accurately as it cuts mass quantities. Automating for Efficiency What if the saw were capable of tackling the material handling jobs without the need for an operator? What if the cut piece could be removed from the saw automatically, deburred, and stacked or palletized, without an operator? What if the new material could be delivered to the saw and put into a queue while the machine is still processing the previous cut job, without an operator? What if the remnant could be measured and put back into storage automatically while the saw is still cutting so that it could be used again? That makes four "what-ifs," but these aren't theoretical what-ifs. Such sawing systems do exist. While it is relatively easy to automate processes that repeat (as in mass production cutting), the big challenge is automating material handling for single-piece cutting. Sawing Center 101 Six elements are necessary for automating a saw that makes one-of-a-kind or two-of-a-kind cuts. 1. An automatic storage and retrieval system (AS/RS) designed to store all the raw materials that need to be cut in a specific time period (for example, three weeks). 2. An automatic crane capable of handling individual workpieces. It must first load each piece of raw material into the AS/RS as inventory; pick the workpiece from its storage location; and deliver it to the infeed conveyor of the sawing machine. The crane is also responsible for storing the remnants after the cutting process is complete. 3. A quick-change station that facilitates feeding the workpiece to the saw while returning the remnant to the crane. 4. A CNC sawing machine capable of sawing all the materials stored in the AS/RS. 5. A sorting unit on the outfeed side of the saw to put the cut pieces into boxes or onto pallets for further processing. 6. An inventory management system (IMS) that controls and monitors all the processes in the sawing center. The last item, the IMS, is the system's brain. An industrial-grade server provides the connections between the system's programmable logic controller and the other five elements. Cut orders can come from any of several sources. The two most common are your management resource planning (MRP) system or a keyboard on the shop floor. Modern technologies also enable orders from remote locations that are transmitted via the Internet to the IMS. After receiving the order, the IMS server checks for the necessary inventory and starts the sawing process if the right material is available in sufficient quantities. After the order is complete, an order confirmation is sent back to the order's originating location and the inventory level inside the AS/RS is adjusted for the just-finished order. The AS/RS of a sawing center is typically a cantilever system with enough cantilever arms to store enough inventory for a given production run (typically two or three weeks). Since the cantilever arms require a certain material strength, additional cassettes are often used to store material that is too thin or too warped to be stored on cantilever arms. If the inventory management computer is the brain, then the saw is the heart of the sawing system. Before a system can be designed, some analytical work is needed to determine the: - Type of saws necessary. - Number of saws necessary. - Type of sorting necessary. The type of saw (band or circular) depends almost entirely on the material spectrum that needs to be handled and cut. If the majority of cuts are in material sizes 6 in. and larger, a band saw is likely the most suitable. If the majority of cuts are on workpieces smaller than 6 in., a circular cold saw is likely to be the best choice. However, these are just guidelines. Only a detailed sawing analysis will show which saw is the right one for a given application. Some sawing center installations have both machine types. Again, the choice depends on the work to be done. Like the type of saw, the quantity of saws depends on the cutting to be performed. Because the material handling is done automatically, and because the system is a truly lights-out cell, the rule of thumb is that one fully integrated saw replaces three to five stand-alone saws. Unattended Postcutting Handling The process of sorting and handling the material after it is cut has a big impact on system efficiency. Getting the cut parts into a container so they can be moved to the next machine shouldn't be a bottleneck. The easiest (and least expensive) way is to "let 'em drop." Unfortunately, this doesn't do the trick. Depending on the job requirements, the random position of the cut pieces in the box together with a 2-ft. free fall into the container might be unacceptable. A machine-mounted chute that directs the cut pieces into the container is an improvement, but this doesn't lend itself to lights-out operations. Such a system can run unattended only until the sorting containers fill up. An efficient solution is a robot. Depending on the shape and weight of the piece, the robot automatically selects the right tool, either a gripper or a suction cup. If the cut piece is too short (less than 2.5 times its diameter) for a gripper to hold it securely, the robot automatically changes to a vacuum system and picks the appropriate suction cup. After the cut piece is removed from the machine, the robot places it into or stacks it onto the container or pallet. To make this solution work in a lights-out factory, the robot measures the container and optimizes the stacking pattern based on the workpiece dimensions and those of the container. As it was with the precutting processes, the goal of postcutting operations is to maximize throughput by having all of these processes run continuously and unattended. The team at TecSaw understands the need for extreme performance and is committed to providing solutions that will increase your productivity. We provide the best products on the market and the value-added services that maximize every dollar. With repair and maintenance programs and just-in-time delivery, TecSaw is the home of extreme performance. Visit our website at www.TecSaw.com or call us at 1.888.TECSAW.1 to learn more about extreme performance. This article excerpt is based on an original piece by Werner Rankenhohn, President, KASTO Inc. FEATURED PRODUCT BOMAR Individual 520.360 DGH Product Features * Semi-automatic, double column band saw machine * 20" x 14" cutting capacity * Miter cutting in both directions (60R/60L) * Frequency controlled direct drive Why Choose BOMAR? * Affordable, high quality band saw machines * Innovative design features * Extremely versatile http://www.tecsaw.com/Code/Brand/Product/newmachinery.aspx?brand=Bomar&product=ind-520-360-dgh.htm NEWS The Montreal Manufacturing Technology Show 2010 is coming May 17 - 19 We invite you to attend the Montreal Manufacturing Technology Show from May 17, 2010 to May 19, 2010. This year’s event is being held at Place Bonaventure and is Quebec’s definitive manufacturing show. Visit our partner Proscies Inc. at booth 148 to learn more about machine tools and factory automation technology! http://www.sme.org/cgi-bin/get-event.pl?--001891-000007-home--SME- EXTREME PROMOTIONS * Machine Specials * Circular Saw Blades Specials * Band Saw Blades Specials http://www.tecsaw.com/code/page.aspx?_id=extreme-promotions.htm USED MACHINES * KASTOtwin AE 4 * KASTOtwin A 5 * KASTOssb 260 VA http://www.tecsaw.com/code/page.aspx?_id=used-Equipment.htm SUBSCRIBE (http://www.tecsaw.com/site/News-Resources/subscribe.aspx) UNSUBSCRIBE (http://www.tecsaw.com/site/News-Resources/unsubscribe.aspx) CONTACT US (http://www.tecsaw.com/site/contact-Us.htm) © TECSAW INTERNATIONAL LTD. Visit Today!