Efficient production under the most cramped conditions

SITEC has been able to install five of the compact horizontal DMC 60 H linear machining centres on a space where only four were possible before. ​​​​​​​

For 20 years now SITEC GmbH has ranked as the top German address for sophisticated machining of a multitude of different materials. Its range of performance includes the precision machining of series parts for the car and commercial vehicle industry, for example, as well as the 5-axis milling of highly complex individual parts. The company from Korntal-Münchingen recently installed five highly dynamic DMC 60 H linear precision centres to handle the three-shift production and from the very first workpiece onwards has achieved maximum efficiency and accuracy.

“As a supplier we have to convince our customers with our quality and suppler service if we are to survive long-term in this fiercely competitive branch”, explains Ulrich Sigloch, Managing Director of SITEC GmbH. Car manufacturing in particular – a branch where the company generates a large part of its turnover – requires a special quality philosophy. At SITEC this means, “being even better than the customer expects”. Ulrich Sigloch sees several reasons why this is so: “On the one hand we have highly motivated and reliable employees who are well versed in the high level of required expertise and on the other hand our short and unbureaucratic decision-making channels boost flexibility enormously.”

SITEC puts its trust in particular in its motivated and competent employees who are more than capable of exploiting the full performance potential of the high-tech machining centres.

The majority of its demanding customers come from the field of the car and commercial vehicle industry – for example ZF Friedrichshafen one of the industry’s most reputable suppliers. This cooperation is manifested in a close competence partnership. Meanwhile around half the orders processed by SITEC come from this key player in the branch.  “We produce the housings for the Ecomid truck transmission from ZF, for example”, says Ulrich Sigloch, giving us a little insight into the product portfolio. In this field, the company is in fact the exclusive supplier of ZF. The Managing Director also looks back on a relationship with this customer that has become established over time: “The number of orders we received from ZF has increased progressively over time, thanks certainly to our quality and supplier philosophy.” The processing of customer orders is clearly structured. “Weekly schedules determine our delivery dates and quality regulations require that we measure the parts at regular intervals”, is how Ulrich Sigloch describes the production processes.

Innovative technologies even in the standard version

The coolant units were place on an overhead platform so all the new machines could be installed side-by-side despite the cramped conditions. This meant that the compact horizontal centres could be moved even closer together without interfering with access to their controls and tool magazines. 

Technologically speaking the five DMC 60 H linear centres also come up trumps at SITEC. Ulrich Sigloch goes on to talk about their geometric accuracy: “The direct drives in particular really come into their own with regard to our extremely tight dimensional shape and positional tolerances.” Expressed in figures: the machines have a circular and positioning accuracy of 4 µm and a repeatability accuracy of 3 µm. This adds up to a gain in accuracy of 25 percent compared to machines with ball screw spindles. The high level of reliability is another outstanding feature of the linear technology. “The maintenance costs for these drives are minimal and DMG MORI grants a five-year warranty – now that really is convincing.” Another point that benefits accuracy is the ingenious cooling of the machine. This encompasses all primary and secondary sections of the linear drives as well as the NC rotary table and the main spindle. In addition, the linear drives of the DMC 60 H linear – in combination with the extremely rigid, V-shaped and weight-optimised travelling column made of GGG60 – guarantee the necessary dynamics, even in highly productive 5-axis simultaneous machining. Acceleration here is up to 1 g, the rapid traverse up to 100 m/min.

The Managing Direction also praises the new magazine technology. “The wheel magazine is the perfect tooling solution for us: intelligent, fast and extremely compact.” With its patented wheel magazine the DMC 60 H linear has a tool magazine with space for 40 tools even in its standard version, when equipped with five of these wheel magazines the machine can hold up to 303 tools.
The machine can also be setup parallel to production and idle times already in the two wheel magazine version. The magazine also excels during operation: 2.5-second chip-to-chip times and delivery of the tool furthest away in just 5.6 seconds.