Compact e-chains in Alzmetall machining centers

• What was needed: E4/4L e-chain delivered as a pre-harnessed readychain® system.
• Requirements: High travel speeds and accelerations, compact installation requiring narrow bend radii, continuous load
• Industry: Machine tool manufacturing
• Success for the customer: The E4/4 light e-chain offers exceptionally compact external dimensions and is at the same time particularly robustly built; the readychain® system saves assembly time and costs and makes installation considerably easier for the customer.

Alzmetall GmbH, based in Altenmarkt and recognized as a leading manufacturer in the metalworking industry, has been developing high-performance machining centers since the 1980s. These machines have earned a strong reputation in the premium segment for their precision, quality, and productivity.

One of these machining centers, the GS 650 is a high-performance gantry engineered for maximum precision and dynamic performance. Equipped with highly dynamic, maintenance-free torque drives, the machine achieves positioning accuracies of up to Tp = 0.007 mm while maintaining high machining speeds. These capabilities make it ideally suited for tool and mold making, single-part production, series manufacturing, and a wide range of precision machining applications.

The machine can be integrated into automated production systems using a variety of loading concepts. These include linear robot solutions, enabled by full overhead crane access, as well as pallet changers and articulated-arm robots for front loading, including systems equipped with zero-point clamping technology.

For key system components, Alzmetall partners with specialized suppliers. This includes the energy supply system responsible for delivering power, data, and coolant to the spindle.

The demanding requirements placed on the energy supply system are a direct result of the machine's dynamic performance. During operation, the spindle is capable of rapid movements and high acceleration rates, placing significant loads on both the cables and the cable management system. Combined with continuous operation and a high number of movement cycles, these conditions require an energy chain system capable of delivering long service life and reliable performance.

The challenge in this application was routing a large number of cables to the milling head within an extremely confined installation space while accommodating high dynamic loads, including rotational speeds of approximately 540° per second and around 90 movements per minute. The solution had to maximize the available installation space without compromising the service life of either the energy chain system or the cables.

A further challenge was the requirement for both energy chains to incorporate multiple links capable of reverse bending.

Since igus® products had proven successful with the earlier GS 800 model, Alzmetall determined the GS 650 will also be equipped with igus's readychain® systems.

This choice not only reduces assembly time, but also contributes to the durability of the energy supply system. They allow small bend radii - which also permits compact installation situations - and are characterized by a long service life even under continuous movement stress. This is an important criterion for Alzmetall, because the machines are very solidly constructed.

The GS 650's spindle operates at speeds of up to 30,000 rpm and requires between 50 and 60 power, data, and media lines. These include servo motor cables, hydraulic hoses for tool clamping, encoder and measurement system cables, coolant lines, and compressed air hoses used for spindle cleaning. Preassembled readychain® systems significantly reduce installation and assembly time.

The machine's energy supply system provides movement across three axes. The x-axis operates independently, while the y- and z-axes overlap. To simplify installation and maintenance, all three energy chains terminate in a centrally located distribution box supplied by igus. The x-axis chain is mounted horizontally and uses the machine's upper cover as a support surface, with a bridge-guided design that minimizes installation space while ensuring reliable chain guidance.

During the development of the GS 650, igus engineers were able to take advantage of a newly introduced e-chain series (E4/4L) featuring a significantly more compact design. Despite maintaining the same cable capacity, the chain was 20 mm narrower than comparable solutions. Those 20 mm proved critical, ensuring that the e-chain remained within the machine envelope throughout its entire range of motion. Even with its compact dimensions and tight bend radii, the system supports the high speeds and dynamic movements required by the machine while maintaining reliable cable protection and long service life.