From a paper-intensive process to digital mold manufacturing

Bosch Formenbau GmbH in Mühlhausen has relied on CAD/CAM products from Tebis for over 12 years. When they first began, the mold was still designed on the drafting table or in a 2D CAD system. The CAD department then used Tebis to redesign the mold as a 3D data set just to calculate the milling programs. At that time, 3D design was only a means to the end of generating the milling programs. As CAD/CAM systems very quickly became more powerful, Bosch switched over to 3D design at an early stage. The entire manufacturing process has been structured based on a complete 3D design of the mold for over five years. And the mainstay of the operation is the Tebis Viewer technology. It gives all personnel full-time access to the current data, and it is used all the way from acquisition through NC machining to assembly. The 3D data set for die design always remains the central medium of information.

A first step in manufacturing preparation is the Tebis Feature Scanner. This completely automatically recognizes all of the suitable geometry for drilling. The relevant parameters for manufacturing, such as diameter, depth and thread or toleranced fit type, are stored in a feature. The subsequent NC manufacturing process can access these data again and use them to automatically generate the necessary NC programs. Die manufacturing is then begun. Milling programs for the steel parts are calculated and electrodes are designed, managed and NC programmed on a total of six Tebis CAD/CAM workstations. The current Tebis Electrode module was implemented in the company’s electrode design in 2005. It can be used to quickly extract, modify and augment burn surfaces. The system then automatically suggests an appropriate blank and offers the available electrode holders from a library. The key to this software is the integrated electrode management, which provides all of the information on an electrode, including the designation, position, type, arc gap, material and operator. "We have currently achieved a savings of at least 25% per electrode in electrode design, which is certainly a significant potential with our production of more than 5,500 electrodes per year," says Andreas Schwab, technical manager at Bosch.

But of course an electrode first has to be milled before there's anything to be measured. And, as initially mentioned, 3D milling was the starting point for the Tebis installation at Bosch. However, they are relying more and more on NC programming in the CAM system for 2.5D drilling and milling as well. Because this in turn means that the machine operators don't have to program as much on the NC control, a new working model was developed in which three employees form a team. The tasks are then rotated within this team: each team member works on the machine and in NC programming for specified intervals. The result is that the different work experience is complementary and so the employees can be deployed more flexibly," explains Schwab, "which was also a request that personnel had presented to us."