The second level of machining automation is here. It may not be at every shop or factory yet, but it’s coming.
Exactly what is this “second” level, you ask? I look at the first level as workpiece and part automation in which usually a pallet stacker with a load/unload station serves one or more machine tools in a cell or flexible manufacturing system (FMS). Sophisticated software manages and monitors the cell or FMS, and it can also be tied in with ERP systems to ping the FMS when the delivery schedule changes, waiting for raw material, tools need to be ordered or many other production factors that would impact the cell.
What I consider the second level surrounds cutting tool automation, which is another phase beyond the initial big step involving part handling automation that really permits effective and practical lights-out manufacturing, further removes human error, increases spindle utilization—while reducing cutting tool costs.
The system is comprised of hardware, usually a robot for a single machine tool cell or an overhead gantry type delivery device accessing a centralized tool storage “hive” that can serve larger FMSs.
Software is key to the brilliance of this cutting tool automation endeavor. Added functionality to the current cell or FMS software package alerts which tools need to be loaded and on which machine, monitors tool life, signaling when it needs to be changed, and more.
For example, BAE Systems is home to a world-class, lean, fully integrated manufacturing system that maximizes operator and machine efficiency that manufactures complex titanium components for the F-35 aircraft.
In addition to an impressive and large pallet and workpiece stacker system, the British company has included cutting tool management.
Results show they can reduce the amount of redundant, expensive cutting tools, such as those required to cut titanium, because the cutting tool management and transportation system can deliver the same tool to different machines.
Meanwhile, the software is tracking the life of each tool and will alert when the tool needs to be replaced and also perform the replacement task.
They also don’t need extra large capacity tool changers on each machine, saving floor space. Most cutting tools are stored in a centralized tool storage section within the FMS.
Another case in point is Kempf CNC-Technik, which manufactures simple to highly complex components in batches of 1 to 500, as well as prototypes for pneumatic and hydraulic applications, for the automotive and construction industries.
In 2013, the German company invested in its second Fastems FMS with a raw material store, 156 pallets on four levels, seven machining centers, and four loading cells. One outstanding feature of this system is its second level of automation: the Fastems CTS (central tool storage), which holds 2,500 tools, and a robot for transporting the tools.
Because each machine also has its own tool magazine with 60 tools, it can access 3,200 tools.
And this is from every machine, because a gantry system with the robot conveys the tools from the central storage to the appropriate machining center as required.
For unique tool identification by the robot’s reader, each individual, pre-set tool is equipped with an RFID chip. Around 1,000 tool transports and 500 pallet transports take place in the system each day.
The average spindle utilization of all machines is between 95 and 98 percent.
Stefan Kempf, the company’s CEO, said, “The flexibility we gain by being able to process every workpiece on every machine in the FMS is so great that we want to continue with this approach.”
Kempf CNC-Technik’s third FMS is now operational.
Those are the compelling benefits that the second level of automation—cutting tool storage, transport and management—can offer.