“We have earned a certain reputation in the market when it comes to the highly economical yet precise machining of series parts,” says Dipl.-Wirtsch.-Ing. Jörg Schmauder, Managing Director of Sales/Marketing at Schwäbische Werkzeugmaschinen GmbH (SW) in Waldmössingen, Germany. The basis of the company’s success is the special design principles of the machines, which are most commonly multi-spindle machines. The multi-spindle concept itself results in increased productivity and lower space and energy requirements in comparison to classic machine tools with fewer spindles. SW machines also feature a sophisticated loading concept: two-table models have a swivel carrier unit with two driven horizontal carriers with clamping fixtures for workpieces or interchangeable pallets. After loading, this unit completes a 180° rotation. This moves the clamped workpieces into the working area in front of the spindles and the finished parts outside of the working area to be unloaded. A torque drive makes it possible to change the work angle of the carrier, which serves as a fourth machining axis. Optional torque drives are also available for the individual clamping fixtures, enabling five-axis machining.
Short chip-to-chip times for maximum productivity
“At SW, we consider every tenth of a second that a tool isn’t machining the part to be wasted time,” adds J. Schmauder. This is why the company has always fought against non-productive time. The most effective means of achieving this is a high level of dynamics in all movements to and from the workpiece and during tool changes. Depending on the application and size of the machines, linear motors or low-wear ball screw drives are used. The tool changer is also integrated directly into the machine. This high level of dynamics also applies to the axes of the swivel unit. This concept enables a chip-to-chip time of less than three seconds.
Another key feature of the machines is their exceptional robustness. For example, the machine and spindles are designed according to the box-in-box principle and integrated into a stable monoblock. This enables continuous use, even for high-performance machining of materials that are difficult to machine such as stainless steel or nickel-based alloys. This is also a requirement for long-lasting precision.
New machines allow for larger workpiece dimensions
“Despite the many advantages of our machines, there is also a certain disadvantage that comes with the swivel unit regarding the maximum dimensions of machinable components,” says J. Schmauder. Over the years, SW has had several customers request the ability to machine larger components on SW machines. This led to the development of the first machine prototype in the BA W08 series, the BA W08-11, which was developed for machining aluminum workpieces. Several of these machines have already been sold to customers. The use of linear direct drives allows this machine to have an acceleration of 2 g in the linear axes. It has a 35 kW spindle with up to 17,000 rpm at 80 Nm and HSK-A63 interface. HSK-A80 and HSK-A100 spindles are also available. In contrast to the previous machine concept, the swivel carrier and the second work table have been omitted. This solution enables the machining of larger workpieces. The prototype of the BA W08-11 has a working range of 1,500 mm (X), 1,025 mm (Y) and 660 mm (Z). The interference zone of the A-axis has a diameter of 1,650 mm and a length of 1,830 mm. A space version is also available for the BA W08-11, which offers more flexibility for the machining of large workpieces. This model features a larger interference zone diameter of 1,850 mm and length of 1,980 mm on the A-axis. SW has also developed the BA W08-21, a twin-spindle sister model that enables machining of two workpieces at the same time. In this machine, travel of the spindles is 800 mm (X), 1,025 mm (Y) and 660 mm (Z). These specifications apply to the HSK-A63 and HSK-A80 interfaces. In addition to single-table machines with linear direct drives for the machining of non-magnetic materials, SW is also developing single-table machines with proven ball screw drives for the machining of conventional iron, steel, or nickel-based materials.
Extensive automation capabilities
In today’s industrial climate, customers demand more than just good machines: they expect fully automated and validated processes for precisely defined tasks,” says J. Schmauder. SW has been meeting these challenges for a long time, he says, and has extensive experience in planning and implementing sophisticated manufacturing solutions. Automation experts have at their disposal powerful IT-supported planning tools such as simulation processes and tools for feasibility and material flow analyses. This enables workpiece costs, for example, to be calculated as early as the planning phase. The customer thus has a reliable set of figures for his estimates in advance of his investment decision. Of course, automation also includes robots and workpiece or tool storage, as well as various types of auxiliary equipment.
This naturally also applies to the new models in the BA W08 series, which can be automated with a variety of solutions. One solution to facilitate the loading and unloading of large and heavy workpieces for the operator at the machine is the integration of the TopRob. The machine is loaded and unloaded with the aid of robots on platforms or gantries above the machine. Multiple grippers enable the rapid exchange of finished and raw parts. Another option is to load and unload the machines from the front with an SW FloorRob.
In addition to machining, SW’s automation capabilities also extend to numerous other processes that take place in modern production lines. These processes include cleaning, drying and preservation, assembly and testing, and packaging for transport. SW’s automation team integrates third-party processes into the production lines and assumes overall responsibility for them. Depending on the overall circumstances of the production line, SW automation solutions also enable lights-out machining.
life Services: Support throughout the life cycle
“With life Services, we offer our customers a broad, interconnected selection of support services throughout the life cycle of their machine,” says J. Schmauder. This cycle begins with life academy and life startUp, which offer thorough training and direct support during startup and ramp-up of production. During the entire service life of the machine, the customer has access spare parts and service at any time with life parts and life help – via both remote maintenance and service technicians. With life upgrade, the machine remains operational for many years with upgrades to hardware and software, or even a complete retrofit.
Today, the online collection, archiving, and analysis of data generated during production with the use of life data is becoming increasingly important. For this reason, the machines are extensively equipped with sensors that record all essential operating parameters. Customers retain full control over the types and scope of the data collected, as well as the analysis methods used. With the tools, the operating status of the system and the usability of the tools – for example deviations or even malfunctions with regard to concentricity or breakage – could be continuously tracked and the machining history documented down to the individual workpiece. The analysis of the data also provides indications of impending failures and helps in the planning of maintenance intervals and the stocking of spare parts.