„Producing parts faster“

Prometall: High Quality Automotive Connectors

Many parts can be manufactured quickly and economically in outstanding quality using Bihler technology – a fact that has been well known at prometall Fertigungstechnik GmbH in Rieden am Forggensee for many years. And for a recent order for the manufacture of automotive connectors, it was vitally important for the company to use Bihler technology – in the form of a new GRM-NC servo stamping and forming machine with the LEANTOOL radial and linear system.

A lot is going on at prometall Fertigungstechnik GmbH in Rieden am Forggensee. From the milling and lathing machine through wire and spark erosion systems and on to the punching machine, Bihler stamping and bending machine and a combination stamping/laser machine, almost all the equipment in the ultra-modern prometall machine pool is in use. The company supplies hinges and drawer guides for the furniture industry as well as contacts for the electronics industry and utensils for kitchen use. “Things are going well and we are very happy with the current order levels”, reports Andreas Hofer, Managing Partner at prometall Fertigungstechnik GmbH. “One of the secrets of our success is that we have a very broad range of activities, plan and act with an eye to the future, always meet our deadlines and make sure we achieve the highest quality standards.” From the very beginning, prometall has been supported in this by technology from Otto Bihler Maschinenfabrik. Andreas Hofer started his training at Bihler in Halblech exactly 50 years ago, at that time still with Otto Bihler. And when Andreas Hofer founded his first company, prometall Werkzeugbau GmbH, as a pure contract manufacturer in 1987, the first series production of stamped and bended parts three years later naturally got underway on a Bihler machine. “Even back then, there were parts that could only be produced on Bihler systems because only these could deliver high production speeds coupled with accuracy of a hundredth of a millimeter”, explains Hofer.

Clear decision

Technology from Otto Bihler Maschinenfabrik was therefore even then a guarantee for the success securing of orders – and it still is today. “At the start of the year, we received a new order for the production of electric contacts for automotive communications”, reports Hofer. “We were selected ahead of a number or our competitors because it was clear that we would use Bihler technology to produce the parts, meaning that top component quality was assured.” However, it was equally clear that prometall would first have to make the corresponding investment, more specifically in the form of a GRM-NC servo stamping and forming machine and the LEANTOOL radial and linear tooling system. Andreas Hofer was in no doubt about this decision: “Only businesses that use and fully understand the most recent technology will reap the opportunities present in the market and succeed in the future”, says the founder of the company, in which his two sons, Michael and Andreas, now also work. Michael Hofer is responsible for planning new tools, while his brother Andreas heads the design engineering department at prometall.

Perfect technology

The decisive factor in the investment in the GRM-NC and the LEANTOOL system was not just the required quality but also the fact that the contacts could only be produced at the desired speed using the Bihler technology. This is because the highly complex, pairwise module requires a very large number of demanding operations. These include the shaping of an internal bushing in the galvanized part, which is coated with a noble metal, as well as the zero-play insertion of a rolled internal spring which is first stamped and bended from a copper strip measuring one tenth of a millimeter in thickness. The manufacturing process also involves feeding in a plastic pin as a contact protector and, of course, everything is completely oil and grease-free. “The technology is simply perfect for this application”, explains Andreas Hofer.

Concrete benefits

As usual, prometall produced the entire design and all the tools for the new automotive contact itself – however, on this occasion also on the basis of the LEANTOOL concept for radial and linear manufacturing. The advantages of this system were soon demonstrated in practice, even independently of the new contact production order: “In combination with the GRM-NC, the LEANTOOL modular system makes it possible to produce sample parts and small runs particularly economically and in top quality, while simultaneously reducing the tool throughput times to a minimum”, says Michael Hofer. “More concretely, this solution enables us to save 30 percent in terms of tool costs, while also being able to manufacture the tools themselves in only two-thirds of the time it used to take. And in the production hall, the setup times have been more than halved to an average of two to six hours”, confirms Andreas Hofer junior.

On-time delivery

Alongside the high component quality and reduced costs, this time saving is another secret of the success of this company, which now already has two GRM-NC machines. “With Bihler, we are simply faster and more economical for certain parts”, says the company’s founder Andreas Hofer summing up. As a result, prometall was able to keep to the extremely short delivery period of only four months for the automotive contacts. Since then, it has also been possible to manufacture other LEANTOOL tools equally speedily, including eight items just for the different variants of the new connector.

Definitely the right path

It is clear that the implementation of the LEANTOOL system went equally swiftly. “It took us twelve weeks from starting work with the LEANTOOL through to the first finished part”, reports Andreas Andreas Hofer. “And it must also be remembered that the more we use it, the better able we are to exploit the potential of the system for our purposes.” The use of the GRM-NC and the LEANTOOL radial and linear tooling system has also been warmly welcomed by the workforce and the new technology has been very positively received by the younger employees, in particular. All in all, this new chapter in the company’s history, which has been ushered in by prometall with the GRM-NC and LEANTOOL system, is a complete success and Andreas Hofer has no doubts: “In this way, we have been able to win new orders and continue to shape our future success. With the new Bihler technology we are definitely on the right path.”