PC-based control automates tool magazine

With the increasing demands on machining technology and the growing importance of flexibility and productivity, the need for tools is also increasing for machine tools. Eberhard Hahl, Managing Director of Wassermann Technologie GmbH in Eichenzell near Fulda, explains: “The new tool terminal was designed to meet these current customer requirements. Only the diameter of the tools and tool drums are fixed. However, the tool length, length division, number of tools, tool cleaning, tool holders and RFID tool data acquisition can be freely configured
. Another special feature is the extremely compact design. This is achieved by using tool drums that run inside each other, i.e. not next to each other.”

Christoph Neuhaus, application software developer at Becker Engineering GmbH in Leichlingen, adds: “High flexibility includes the ability to integrate a wide range of machine tools with different control platforms. The openness of PC-based control is the
decisive factor here. For example, third-party software can also run on the Beckhoff control hardware, which facilitates access to the tool tables of the respective machine.”

The concentric tool terminal consists of one or two additional, intermeshing drums as required. The tools are handled by a linear unit with an integrated tool changer. This takes care of placing the tools in the drums as well as feeding them into a tool buffer or directly into a tool changer on the machine side. Eberhard Hahl explains: “The tool terminal offers tool management for up to 9,000 tools and is suitable both as a direct magazine and tool storage for tool management and as an extension of existing tool magazines or a central supply magazine for several machine tools.”
Julian Becker, application software developer at Becker Engineering, describes the special feature as an intelligent additional magazine: “The tool terminal can work completely independently. This is ensured by its own tool management, database and sequence control as well as its own interface to the machine tool. In addition, the software for external additional handling, the interfaces to peripheral devices and the integrated recording of tool data are also available in the tool magazine itself.”

The high flexibility of the tool terminal offers clear cost benefits for the end customer, as Eberhard Hahl explains: “With the tool terminal, we have designed a versatile standard magazine, which is reflected in a good price-performance ratio. However, if required,
can also be individually connected to the machine tool, for example. The tool terminal is available as standard in two model variants – S-Curve for up to 280 tools and D-Curve for a maximum of 570 tools.”

Becker Engineering has been gaining experience with PC-based control since Christoph Neuhaus sees numerous advantages that have resulted from this: “Among other things, we benefit from the fact that the PLC and additional high-level language applications can be implemented consistently on one platform. There is also the good scalability. It allows the control project to be easily migrated to more powerful hardware, for example equipped with a multi-core processor, if performance requirements increase.”
Wilm Schadach, Beckhoff sales office in Monheim, adds another aspect: “PC-based control also offers complete consistency from a handling and engineering perspective. In addition to PLC functionality, motion control and visualization, the tool database can also run on the same platform. This has proven to be a significant advantage in the overall design of the system.” According to Julian Becker, it was also very easy to become familiar with Beckhoff’s PC-based control technology: “The use of familiar, standardized programming languages significantly simplified handling.”

Becker Engineering also benefited from the wide range of data communication options via TwinCAT ADS. Christoph Neuhaus comments: “ADS enables very easy access to the PLC data from the high-level language application. And conversely, an ADS server can also be conveniently developed in a high-level language
, which can be easily accessed from the PLC. In this way, reliable data transfer between the tool magazine and the machine tool, for example to exchange order numbers or evaluated user data, is achieved without great effort. In addition, the necessary updates can be conveniently fed in at
in the event of subsequent further developments and Industry 4.0 solutions can also be implemented with the client/server architecture available via ADS communication.”

Another important aspect of PC-based control for Christoph Neuhaus is the availability of the latest Windows operating systems, the good update policy and the simulation options available without additional license or hardware requirements: “The entire system can be simulated on your own development PC. For example, you can change the motion axes to simulation axes or map the I/O behavior close to the hardware using software simulation modules.”

In a currently implemented tool terminal with two drums, a total of five servo axes ensure fast and precise tool handling. The corresponding AX5000 Servo Drives and AM8000 Servomotors are controlled by a CX2030 Embedded PC with TwinCAT NC PTP. This realizes
a rotation axis for each of the two tool drums as well as a vertical axis for reaching the desired drum level, a horizontal axis for gripping into the plane and a rotation axis for a double gripper. Another automation task is the
pneumatic control for the double gripper. Eberhard Hahl adds: “The tools are transferred from the drum to the outside via the gripper rotation axis. This can also be designed as a telescopic axis in order to transfer the tool directly to a magazine on the machine side without intermediate handling.”

The motion control application was implemented in TwinCAT with the help of PLCopen motion blocks, which, according to Christoph Neuhaus, has proven itself in practice: “Programming the motion functions with the motion blocks was very easy and extremely time-saving. Another advantage of Beckhoff drive technology is the One Cable Technology (OCT). This allows assembly and material costs to be reduced and smaller cable drag chains to be used, which facilitates a compact design. In addition, the electronic nameplate significantly speeds up commissioning.”