Multitasking Machining

Manufacturers embrace multi-function equipment to gain a competitive advantage.

All manufacturers want to boost productivity, and an increasing number are purchasing multitasking or multi-function machines that can perform several different machining operations. These machines are proving to be a competitive advantage by producing accurate and repeatable finished parts.

These amazing machines were prominently displayed and demonstrated at the IMTS show last month in Chicago (see last week’s edition for details on IMTS). Beyond their multitasking capabilities, these machines are versatile in other ways, including the ability to produce one-off, complex parts or small lots of parts that may or may not be members of the same family. These devices can machine anything from big chunks of raw steel down to minuscule medical devices, and everything in between.

Multitasking equipment that combines different machining processes is not exactly a new idea, although the range of operations the equipment is capable of and the end results have expanded quite dramatically in the past few years. For our purposes here, we’ll define multitasking equipment as machines that can perform more than a single metal removal operation, simultaneously from one part with more than one cutting tool or from a number of parts.

There was a relatively large number of multitasking machines displayed and demonstrated at IMTS, and I noted some trends in what I learned from the various vendors on the exhibit floor, including:

• Multitasking equipment is well-suited for most lean manufacturing strategies and schemes.
• Multitasking continues to expand from the traditional mill/turn combinations to include more grinding and other finishing operation combinations.
• It’s getting more difficult to delineate multitasking equipment as either strictly a machining (milling) center or a turning center -- the processes are increasingly being combined in equipment.
• The power and workpiece-size handling capabilities of multitasking equipment increasingly match those of traditional standalone, discrete-process machines.
• To keep pace with advancements in multitasking equipment, associated controls and software have become more sophisticated with higher levels of integration.

Equal Partners

Beyond the machines themselves, software and controls are essential for optimizing tools and tool paths, workflow sequences, collision avoidance, scheduling and various types of production simulation and analysis. Like much of the rest of the product design and production cycle, complex machining and CAM are downstream areas that are finally moving to 3D in a big way. This indicates that 3D CAD data is increasingly being used instead of 2D drawings for CAM and actual machine tasks. Will drawings ever completely go away? No, but they will continue to decrease in number as time goes on.

As you can imagine, it’s not easy for software to support multitasking machines -- there is a significant additional programming investment involved. It’s especially difficult because support for a multitasking machine is more complex than that for a three-axis mill or two-axis lathe. On top of this, the software must have a streamlined and intuitive interface so it’s easy to use. The software side of the equation is just about, if not equally as demanding, as the hardware side.

The Middle Man

Controls act as the intermediary between the multitasking equipment and the software. Major trends here are network-centric controls and architectures based on an emerging Profinet factory automation standard, also known as Industrial Ethernet.

Controls are also increasing their capabilities in areas such as design parameter support, CNC logic simulation, process monitoring and servo motion tuning for decreasing machine energy costs. Outside the world of production, controls are often the lost stepchild of production tools, but they are just as essential as the machines and software.

Implementing Multitasking Machines

Considering the opportunities and challenges that multitasking machines present, the main reason to implement them is simple: to remove labor from the manufacturing process, such as when transferring a workpiece from one machine to another.

Multitasking machines don’t diminish the need for skilled workers. In fact, people with higher levels of skill are usually required to run them to optimize their operation and maximize productivity. Multitasking also is well-suited for high-value parts with tolerances that demand a minimal number of workholding changes between different machining operations. Although their initial costs can be relatively high in terms of initial purchase and implementation into a manufacturing process workflow, multitasking machines enable manufacturers to shift into higher levels of productivity.

While there’s no consensus on exactly what a multitasking machine should be, everybody agrees that they do more operations on a part than traditional standard machines, and that their future looks bright -- especially as their capabilities and adoption continue to increase. Multitask machines, software and controllers have certainly come a long way, and their future and potential seem almost limitless.