Lean medical manufacturing through compact machining cell advancements

Automation on a smaller scaleIn the past, automation was typically associated with streamlining high volume production. Robots performed a single task and changeovers were time-consuming, difficult and could adversely affect a company’s bottom line. To develop a stronger position in the market, automation manufacturers were forced to rethink automated manufacturing and provide solutions that could adapt to low-volume production. Machine tool builders and robotic integrators were compelled to work closer than ever with fixture and tooling manufacturers to improve the changeover time to maintain the course of Lean machining and to increase productivity of low volume operations. One example of this collaboration was the development for medical manufacturing of a robotic cell that minimized waste in set up and work flow. FANUC, a leading supplier of robotic automation, and Methods Machine Tools, Inc. developed the cell, named FANUC RoboDrill Med Cell (Med Cell) that addresses all these elements and is highly efficient for low-volume operations. The Med Cell is designed so that raw goods are staged for efficient in-feed flow and accurate part fixturing in the machine tool by the robot. The Med Cell offers 5-axis machining capability using a tilt rotary table and is specifically geared to short run production requirements, while maintaining a high level of unmanned operation.  It provides Lean automation as a complete pre-engineered, fully-integrated production machining cell for automating the loading, unloading and machining of medical device parts.An off-the-shelf “EDM-style” chuck that uses a common fixture base holds the raw material. The part is mounted on a pallet, fixtured accurately and rigidly in a corresponding tooling chuck that is air actuated, eliminating the need for new and redesigned fixturing. Then, as machining begins, parts are machined completely for that particular application without interruption. Parts flow out of the cell for final packing or other required operations. The entire process is automatic with minimal set-up required. When a changeover is required for the next short run, simple modifications are made to the in-feed system and some minor adjustments performed before the next run. In many instances, manufacturers can run several different jobs in a single set up with little or no changeover, increasing productivity and profitability of their small lot parts of varying sizes and materials.  The Med Cell commonly produces complex medical components manufactured from stainless and cobalt chrome materials on a short run basis. In most cases these parts are leaving the machining cell completely finished.  FANUC understands the need for Lean and even applies these principles to its own manufacturing. When building the company’s Robodrill Milling machines, FANUC incorporates robotics to handle the castings and components, fixtures them in large sized “EDM-style” chucks and machines components from raw material, completing final assembly with minimal change over. Material flow and other considerationsRobotic automation is available, cost-effective and is an ideal way to increase accuracy and productivity while reducing costs.  However, simply adding a robot to your operations will not increase efficiency. Robotic loading in a cell requires significant consideration of raw material flow. Material handling can play a vital role in improving a manufacturing process, and addressing this core issue is critical to implementing a Lean automation cell. Well-designed in-feed flow is critical to maintaining a Lean automation cell; a robot is useless without incoming raw material. Robot manufacturers have made material handling easy with simple-to-use software. Short run production with robotic loading and unloading is now a very affordable solution for the average job shop or a 1st or 2nd tier Medical OEM. After tackling the raw material flow issue, you must then consider handling, locating, fixturing, machining and removal of the product from the cell. Keeping a rapid material flow from raw goods to finished product will decrease product cycle times, increase productivity and capital equipment use, and decrease inventory. Smaller, customized part runs become economically feasible.Taking advantage of simple robotic interfaces and innovative workholding is important, but manufacturers can now benefit from an entire automation “cell” by choosing solutions that include capabilities such as 5-axis machining. These cellular technologies hold the key to keeping manufacturers competitive and profitable.  Steve Bond is National Sales Manager, RoboDrill, RoboCut and EDM Products, for Methods Machine Tools, Inc. (www.methodsmachine.com)