DVS Group

WMS practical report:

Old turned New: Retrofitted machine leaves nothing to be desired

Old turned new: Machining chamber of the retrofitted machine

With its package for over­hauling and modernisation from a single source, Werkzeugmaschinen­bau Sinsheim GmbH has made an out­standing name for itself as a service specialist in a wide range of different industrial branches. One example of the comprehensive services available is a centre-drive lathe delivered in July, which underwent a general overhaul in Sinsheim and was equipped with numerous new features. The customer saved around 30 percent of the costs which would be due for a new machi­ne with a similar performance level in this case.

A well-known company from the printing machine sector had purchased the centre-drive lathe CM 704 from WMS in 2003. It has been performing reliably and without complaint ever since, manufacturing rol­lers for the printing industry. Yet the de­mands made by the market have changed over the years. The component spectrum has been extended to include larger – and especially longer – parts. In addition, a higher degree of automation and faster machining were on the wish list.

Which is why the question came up: is it better to buy a new machine or have this one overhauled and modernised? Alongside the price advantage of around 400,000 euros for the retrofit variant, the customer was also convinced by the com­prehensive advice and engineering service provided by the WMS experts. Taking the customer requirements concerning auto­mation and extended workpiece spectrum as a starting point, the mechanical and electrical engineers as well as the software developers from WMS drafted a complete package. From the overhauling and exten­sion of the machine by additional elements through the necessary tools and machining strategy to software for manufacturing the planned products, the customer received everything as a unified whole – and from a single source.

Additional features increase degree of automation and machining speed  

In the case on hand, the machine was completely dismantled first, in order to establish which parts would have to be replaced or processed. The tailor-made new design features were then integra­ted when the machine was reassembled. To increase the degree of automation, the machine was equipped with a gantry ro­bot for automatic loading. A workpiece magazine which can house ten workpieces with lengths between 800 and 3,000 mm and up to 200 mm diameter and 250 kg in weight was also added. Thanks to this supply, the machine can now work for two or three hours fully automatically.

The optimum machining of very long parts is made possible by two newly fitted, self-centring steady slides. In addition, the lathe machine was turned into a lathe-milling machine during the modernisation process. An additional Y-axis and driven tools were integrated for this purpose. This allows milling and drilling machining to be carried out in addition to turning in one clamping.

Great improvements were made in terms of cooling and lubrication during machi­ning, too. On the one hand, a high-pressu­re cooling lubricant system was integrated. On the other, the machine was equipped with a system for treating cooling lubri­cants for the first time. Thanks to this filter system, most of the cooling lubricants can be reused in a recycling system, significant­ly reducing the costs for new and the dis­posal of used cooling lubricants.

Latest control technology

To be able to make optimum use of all these new mechanical possibilities, the machine was equipped with a new con­trol unit. With the Siemens 840d Solution Line, the axes and spindles, the number of which has been doubled from eight to 16, can be controlled without any problems and, thanks to a network connection, can be serviced both locally or remotely. The Ethernet connection also allows the ma­chine to be integrated in a concatenated production line. With the new control unit, the Siemens Safety Integrated concept is also finding its way into the machine. This concept integrates safety technology in standard automation.

The machine was delivered and put into operation in July. Together with the machi­ne, the customer received detailed docu­mentation of the overhauling and moder­nisation work, which took a total of nine months.


bau Sinsheim GmbH

Werderstrasse 84
D-74889 Sinsheim

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