More than half of the volume of an unprocessed block is often cut away as waste, and this is for workpieces with surface areas of several metres and measuring several centimetres thick. To enable these workpieces to be produced in a reasonable time, RIVA employs a whole range of machining centres with multiple spindles, essentially constituting two, four or six NC machining centres on a shared machining table. Even so, machining times of 35 to 50 hours are not uncommon. The smallest machine has a machining space of 800 x 500 x 550 millimetres, while the table for the largest machines measures 14 by 4 metres. The achievement of high precision, optimum surfaces and reliable machining over the course of many hours requires constant and highly precise monitoring of machining processes and tools, for which RIVA uses measuring systems from Blum-Novotest on 15 machining centres – some of them have laser measuring systems installed, some have probes in the tool magazine, and many have both. Z-Nano type tool setting probes are also installed in some machines.
BLUM’s laser measuring systems are offered as unified systems, where the transmitter and receiver are seated on a single mount; or as single systems, where the transmitter and receiver are positioned separately from one another in the working area. At RIVA, both types are in use – for instance, six of these systems are installed in a special-purpose machine from Chiron with six machine heads. This allows all sizes of the tools used at RIVA to be measured, ranging from 0.3 millimetre ball nose mills to facing mills of 250 millimetres in diameter. One of the major benefits of laser measuring systems is the high level of precision and reliability under harsh working conditions. The laser measuring systems are mainly used at RIVA for Tool Breakage Monitoring and Single Cutting Edge Monitoring, allowing even the smallest breakages of cutting edges to be detected with µm precision while the spindle is running at nominal speed.
Alongside the optical measuring systems, tactile measuring systems such as the TC60 wireless probe in Backnang are also used. The probes are used in particular to detect workpiece reference points. In RIVA’s large machining centres, probe systems with BRC wireless technology are used. Compared to the commonly used infrared communication, this has the advantage that there does not need to be a direct visual link between the probe and receiver, and it allows up to six measuring systems to be controlled in sequence. To keep the measurement process as short as possible and avoid consuming valuable machine time in measuring cycles, BLUM has designed its probes to support fastprobing speeds. When probing, speeds up to 5 m/min are possible, depending on the type, without jeopardising the measurement precision of 0.3 micrometres. “BLUM sales representative Erhard Strobel has been able time and again to help us with tips on how to perform the numerous measuring cycles at the right location, allowing us to optimise our manufacturing process,” said Dietrich Herz, summarising his overall positive conclusion. “We are very satisfied – both with the products and with the support from Blum-Novotest.”
Founded as an engineering office in October 2004 by Hermann Püttmer, RIVA plans, designs and executes façade construction projects. A major project in Mecca, Saudi Arabia proved to be a major milestone in the company’s history. A glass façade structure, over six storeys in height, looms over the world’s largest clock at the peak of the monumental Mecca Royal Clock Tower Hotel – presently the third highest building in the world. The “jewel”, so named for its form, represented the foundation for the intensive partnership in the expansion of the Holy Mosque in Mecca, Islam’s most important and largest mosque. Since then, RIVA has also taken on the production of numerous construction elements made of stainless steel and aluminium – moving roof structures made of glass and stainless steel, gilded and powered multi-leaf doors, and complex façade elements constructed in many different ways in terms of size and structure.