Processing housing units places high demands on the machines. As well as the aforementioned precision, high levels of reliability and large travel paths are required. Not least for the extra-large screw compressors, whose housings have a volume of around a cubic metre and a weight of roughly 1.5 tonnes.

In order ensure economic housing machining for the entire product range, GEA took the decision to make their facility in Berlin state of the art. Since numbers have grown so much recently that part of the production had to be moved out, returning to entirely in-house production should create additional capacity. 

The plan was to replace two ageing horizontal machining centres from the beginning of 2015. This came with the need to dramatically reduce machining times (especially downtimes), to increase machining accuracy and to devote particular attention to high-precision depth machining of holes. A high level of machine availability was also in the list of requirements along with the most up-to-date Siemens 840 D sl controller and a switch to HSK-100 tool holders. "We considered every detail in terms of optimising the machining process", stresses Production Manager Hanno Heim. "Then we thoroughly compared the relevant machines from various manufacturers. This included time studies for a reference component, involving all the necessary machining processes."

The HEC 630 began operating in February 2015, and the HEC 800 in July. Startup went smoothly for both machines. Series production was able to start just days after handover, as the horizontal machining centre specialists from Chemnitz also provided technical support. Part of this was the preparation of the work step sequence for different housings, checking the tools in use, starting the program and finally achieving a good part.

Ronny Kolbe works particularly intensively with the new HEC machining centres. The specialist in production planning and control works together with Burghardt Krüger to create and optimise the CNC programmes run on it. He also mentions another plus point which has already been proven in practice – the tool magazine with 240 slots that can automatically accommodate tools of up to 340 mm in diameter and up to 800 mm in length: "This capacity makes us very flexible and means we don't have to constantly re-tool, even for the smallest series runs. We were also able to reduce clamping operations per housing from three to two." Despite its large tool wealth, the tower magazine requires only a small footprint in comparison to other solutions, which is an important argument in cramped conditions. In addition, tools can be loaded and unloaded during machining time.

The new Siemens 840 D sl controller has gone down well with machining staff. Although a Siemens CNC 840 D was installed in the previous machines, the latest generation allows a much more relaxed way of working, as Ronny Kolbe explains: "The control panel has been redesigned. A large screen and the implemented operating software make work easier and simple to understand with numerous pictograms. The simulation options have also improved significantly. The operators can use Help and service routines for quick fault diagnosis."