After being fundamentally overhauled, an almost 30-year-old large-scale drilling machine Wotan Rapid 6 was brought up to current standards with particular regard to precision.
The maintenance engineers of Schuler Pressen GmbH in Weingarten together with the service technicians from Dörries Scharmann Technologie GmbH (DST) from Mönchengladbach managed to solve this complex problem. Dörries Scharmann, a member of the Swiss Starrag Group, together with the mechanical maintenance team from the Schuler-Werk in Weingarten fundamentally retrofitted a Wotan Rapid 6 large-scale drilling machine.
„The intensive discussions, including those with the engineers from Dörries Scharmann, paid off because the value of the machine after extensive tuning measures has significantly increased“, says Dipl.-Ing. (FH) Alexander Horn, Head of Maintenance, Planning and Property at the Weingarten factory belonging to Schuler Pressen GmbH. “The mechanical function is as good as new“, he emphasises, “although the old but modernised components are still being used.” To cap it all were the new and state-of-the-art electronics incorporating digital intelligence.
Dörries Scharmann Technologie GmbH (DST) has long had close business relationships with many companies of the Schuler Group. „We carried out the retrofitting because we as machine manufacturers were in possession of the machine documents and in addition have a lot of know-how in this area”, reports Holmer Thomas from DST Project Engineering. In the case of the Wotan Rapid 6 (manufactured in 1987), the largest machine in the Weingarten factory, there was an urgent need to undertake something because of deteriorating quality. “It was only thanks to the ingenuity of our staff that we were able to produce the parts in the necessary quality”, recalls Horn. “Then finally we received the go-ahead for the retrofitting.”
The requirements of the specification were very high because the components manufactured on the drilling machine had to be machined very precisely. The maximum deviation over the total length of 10 m (X-axis) was, after the retrofitting, 60 µm. Schuler and DST modified the Wotan drilling machine at many critical points from the operating point-of-view. For example, the machine was fitted with a completely new bed carriage with a new form of drive. The double-pinion drive used previously was in fact only driven on one side. In the overhauled Wotan 2.0 there is now a double-pinion drive with 2 electronic drive systems. Horn: ”This was a real challenge , because we were confronted with a completely new type of bed carriage”, reports Horn.
Horn’s praise for the total project carries weight for two reasons: On one hand the factory itself has many years experience in machine construction, and on the other hand it is itself very active and experienced in the field of retrofitting. Horn supplies an example: “We are currently retrofitting the transfer system for a large press belonging to a well-known German car manufacturer.”
The Starrag Group Service has currently a staff of over 300 including more than 150 service engineers. (Lb) •