In today’s competitive landscape, factors such as increased flexibility, minimized setup time, and enhanced productivity are crucial for commercial success.

At Lewa Attendorn Gmbh, the need to optimize the machining section and make it more cost-effective arose due to the growing variety of parts, varying materials with diverse dimensions, and the demand for quick and prompt customer satisfaction.

Lewa Attendorn, a medium-sized enterprise with over 150 skilled employees, is a turnkey provider of custom solutions in pipe shaping technology and advanced robot systems, as well as a partner for CNC manufacturing of complex turned, milled, and bored parts. The company also operates the largest vocational training center in the region, training up to 220 trainees for local industry in its well-equipped training workshop. Lewa Attendorn’s capabilities span a wide range of jobs, including drilling and milling, turning and grinding to complete robot welding systems.

Streamlining Production with Zero Point Clamping Systems

Modern production systems and machinery are designed to operate at ever-increasing speeds and efficiencies, often pushing the limits of their capabilities. To address this challenge and explore optimization and cost-saving opportunities, Lewa Attendorn determined that the most effective solution was to shorten setup times by implementing a zero point clamping system.

“On what are manufacturers to concentrate to be more cost-effective? In the reduction of non-productive time, we aim for minimizing the setup times to make manufacturing more cost effective and as a result more competitive,” says Rainer Frisch, head of machining in production at Lewa Attendorn.

Lewa Attendorn began the search for the ideal zero point clamping system manufacturer. After evaluating well-known providers, the team chose STARK Spannsysteme, a part of ROEMHELD Group that is recognized as one of the world’s leading suppliers of zero point clamping systems

“At the start we were very concerned, as we had a zero point clamping system from another manufacturer in use on a machine and had problems with inaccuracies and the mounting plates had become distorted. On one occasion the entire machine was suspended from the crane hook as the operator could not see that the workpiece was still clamped,” explains Rainer Frisch. Robert Hartmann, head of sales at STARK Spannsysteme, was able to very quickly clear up these doubts. “On the STARK system the release is hydraulic, as a result the pallet is raised on release and the operator can clearly see that the pallet has been released. On other systems there is only simple locking, and the operator has no indication of whether the workpiece is clamped or released.”

The team at Lewa Attendorn also had the opportunity to view the zero point solution from STARK live on site and spoke to the responsible machine operators. This further solidified their decision for the STARK zero point solution.

Reduced Clamping Time with ROEMHELD Stark Innovations

Initially, STARK equipped one DMU 100 machine at Lewa with the Speedy 2000 zero point clamping system. They opted for a modified octuple design with larger spacing to improve turning moments. In this setup, retractable nipples are secured with high precision by spring force and released hydraulically. The special nipple shape ensures no damage to the fits during pallet changes. Given the frequent clamping cycles on this machine, Lewa significantly reduced clamping time, thereby boosting productivity.

Once Lewa Attendorn was fully satisfied with the quality, accuracy, clamping process, and setup time, two additional DMU 100 machines were equipped with STARK clamping systems. A large Wotan boring machine was also outfitted with these systems. This Wotan machine is used for manufacturing frames for bogies, complex cast structures, and welded structures in small production runs or one-offs, handling tasks from face milling and shoulder milling with high feed rates to boring, thread cutting, and reverse countersinking.

In collaboration with STARK, Lewa decided to equip the Wotan machine with the Speedy 3000 zero point clamping system. This involved attaching five rails, each with three Speedy 3000 units, to the machine table (2000 x 2500 mm). The reinforced version of this system permits a maximum load of 25 tons. Both pallets and workpieces can be placed directly on these rails. Additionally, a ROEMHELD hydraulic unit was provided for clamping and releasing, featuring an integrated "third hand function." This function ensures that once the workpiece or pallet is securely engaged, it remains in the correct position, preventing it from falling out and eliminating the need for the operator to hold it. The system is also prepared for the "clamping check" option, which can be easily added later.

“Here we have a right-angle clamping plate 2500 mm high. At the moment, 2 clamping plates are fitted, one 1600 mm wide and the other 1200 mm. The clamping plates have been equipped with the retractable nipples. Speedy 3000 are also installed in turn on the clamping faces on the right-angle clamping plates, so the pallets can be changed quickly,” explains Rainer Frisch.

Added by Robert Hartmann, “The entire zero point clamping system from STARK is a modular system. Small, medium-sized, or large pallets can be clamped by using the narrow clamping plate and the wider clamping plate or by using both clamping plates, and there is access to the workpiece from all three sides.”

Here, Lewa Attendorn is using clamping frames 2.40 m high and 3.50 m wide, weighing approximately 3.5 tons, with the workpiece along weighing approximately 1.2 tons.

Successful Integration at Lewa Attendorn

“For us, the situation is much easier and we gain an immense amount of time,” Frisch explained.

Frisch continued, "Before, we lost a large amount of time during setup and during clamping on the clamping plate. We spent approximately 5 hours setting up and clamping alone and the machines were stationary during this time.”

In using the zero point clamping system from ROEMHELD Stark, Lewa Attendorn is now able to clamp workpieces that are to be machines next and workpieces that are to be machined simultaneously. A dedicated setup station in front of the machines has been established for this purpose.

“While the workpiece is machined, we are setting up, as a result we do not lose any time any more and everything is also considerably more convenient,” adds Rainer Frisch.

Gaining a Competitive Advantage with ROEMHELD Technology

With the integration of zero point clamping systems from ROEMHELD Stark technology, Lewa Attendorn is able to drive perfection and high quality while meeting their deadlines. Thanks to the additional capacity, flexibility and setup time reduction, the company is able to increase accuracy and production. With this time saving, competitive advantage is realized as they are now able to better meet customer’s technical, schedule, and economic requirements.

Rainer Frisch commented, “We are very satisfied with the collaboration with ROEMHELD Stark. Starting from the constructive meetings during the planning phase to the service and support on site.”

“Finally, everything hinges on a single point: to reduce the downtimes to be more cost-effective and increase the turnover—and we have achieved this goal with the zero point solution from ROEMHELD Stark,” said by Hermann-Josef Bettendorf, member of the senior management and head of sales at Lewa Attendorn.