When it comes to the production of high-precision parts for industries ranging from aerospace to medical, grinding remains the best, most cost-effective approach to obtaining fine surface finishes and tight tolerances. However, as skilled operators grow scarcer and demanding customers make high-mix/low-volume (HMLV) part production strategies necessary, the traditional approach to grinding these parts with multiple machines and multiple setups has become impractical.
To ensure their customers have the application flexibility and machining power needed for the latest trends in manufacturing, grinding system OEMs continue to incorporate more processes and capabilities into single-machine platforms. This allows even the most precise components to be made with the multi-process approach that has enabled HMLV production paradigms across numerous industries.
One such multi-process system is the MÄGERLE MFP 51—a multi-tasking grinding machine that has, in some cases, resulted in overall process time savings of over 50 percent for components like aerospace turbine vanes.
The MFP 51 offers a full range of surface and profile grinding operations in addition to drilling, milling, and measuring, all with five-axis movement. Whether a shop needs creep-feed, form, profile, reciprocal or classic surface grinding—as well as dressable or electroplated CBN grinding—the MFP 51 performs at a level of flexibility that allows manufacturers of high-precision parts to reduce setup times significantly, a key factor for success in HMLV lean manufacturing environments.
In previous decades, standard lean practices for ground parts revolved around four-machine production cells manned by up to four operators who strove to optimize for low cycle times and consistent part flow. And, because parts that undergo these grinding processes often require some conventional milling, parts produced with this paradigm generally move from the grinding cell to a separate milling machine. This manufacturing strategy worked well for high-volume applications and kept cycle times to a minimum.
Unfortunately, a shortage of skilled labor and a more holistic understanding of manufacturing productivity has made the old approach obsolete. A single MFP 51 with one operator, however, can perform the work of the entire four-machine cell, all without the risk of damaging workpieces when moving them between machines or an imprecise setup causing scrapped parts. Furthermore, the reduction or elimination of setup time and lowered risk of damaged workpieces results in considerable upstream and downstream savings across entire production lines.
To do the work of four machines, the MFP 51 needs to have the tool capacity for all its multiple operations. To that end, the machine includes a 66-position tool magazine in a gantry-style system and quick-change pallets to minimize setup time. The palletized approach to workholding makes it simple to perform numerous operations on a part with minimal risk—the dimensional relationship between the part and the machine remains perfect, because nothing has moved.
The tool magazine and quick-change pallets also enable a greater level of process versatility. This is especially important for industries such as aerospace, where a proliferation of advanced materials requires different tools, including those capable of cutting or abrading materials with high nickel content or significant heat resistance. With a tool magazine capable of accommodating 21 grinding wheels, 21 dressing rolls and seven tools—or any other combination of through-coolant metalcutting tools, grinding wheels, and measurement probes—manufacturers can easily keep up with high-mix jobs with varying materials and degrees of precision.
From a pure grinding standpoint, the most important feature of the MFP 51’s tool magazine is its ability to accommodate up to 37 maximum-diameter CBN grinding wheels. On a normal CBN grinding machine, manufacturers are limited to perhaps a single arbor with 8″ (203.2 mm) of diamond roll form. The MFP 51’s expanded wheel and diamond roll changer, however, enables a variety of dressable CBN wheels, each of which can be dressed to shape or used as part of a wheel-roll combination to expand the number and types of features that can be ground on a given part.
An optional RFID-based system automates wheel size records on the wheel itself, a useful feature given the simultaneous tool and dresser roll changer capabilities of the MFP 51. Typical systems will write this data to a given tool position, but with the machine’s new approach, whenever a wheel is used or dressed, the machine records the diameter—accurate to 0.1″ (2.54 mm)—and writes that data directly to an RFID chip in the wheel. This means greater flexibility, faster tool changes and the ability to move tooling between machines.
The MFP 51 includes the new Siemens SINUMERIK 840D sl control, which features a touch-screen interface that users can change into a customizable platform for human-machine communication. The Windows-based control makes it possible to display virtually any media, including video, at the machine, so operators can watch setup instructions before starting and plot their process data live while grinding.
Grinding machines like the MFP 51 help shops create a HMLV production flow, eliminate setup times, and reduce required manpower. And if today’s precision manufacturing shops can’t handle jobs by grinding their parts in one machine, with one setup, they may not be able to afford to take on the jobs at all.