Using DIGILOG technology to 'track down the micron'
- Measuring Components

BLUM production metrology at Carl Benzinger GmbH

Now even the jewellery industry is using state-of-the-art milling technology involving up to five axes. Carl Benzinger GmbH is transferring experience gained from developing and producing such machines to innovative CNC machines for manufacturing high-precision small parts for industrial use. The company incorporates measuring components from Blum-Novotest on all such machines in order to allow for automated production.

"We are always trying to extract the last micron of precision and reliable machine processes are very important to us," emphasises Benzinger's managing partner Rainer Jehle as he explains the company philosophy. "The customer gets a machine that can do exactly what needs to be done, keeping production as simple and efficient as possible." The Carl Benzinger company started developing manual turning and milling machines in Pforzheim, Germany as long ago as the early 1950s. With the proximity to the jewellery industry in the 'Golden City' of Pforzheim, it was only natural that Benzinger machines were used for the individual and mass production of jewellery items. In addition, systems developed and built by Benzinger are also used in other industrial sectors.

One of the special features of the Benzinger machines is the very sophisticated programming that greatly simplifies tool changing and inserting new tools. The user is walked through the process, which is automated as far as possible. Amongst other things, this includes the automatic measurement of new tools, so the process automatically adjusts itself to the length of the new tool. This can only function properly based on extremely precise tool length measurement, and this can only be achieved by using BLUM measuring components. The jewellery production plant incorporates laser measuring systems, while the industrial plant has workpiece and tool setting probes as well as lasers. That means, measurement in the machine is the basis for all automation tasks.

Benzinger has been using BLUM's new LC50-DIGILOG laser measuring system for more than two years now. Its intelligent digital-analogue technology and the several thousand measured values produced by it per second yield several benefits. The LC50-DIGILOG in Pforzheim is achieving even more exact results than previous systems. All tools are measured in the machining centre while rotating, which allows for machining precision that would not be possible with tools measured outside the machine. Some tools are also checked after the machining: Whereas carbide tools are used for rough machining, the finishing is done using expensive diamond tools that are very precise and often cost thousands of euros. To prevent them from getting damaged, it is important to ensure that the previous roughing operation has been completed properly. The measurement is not influenced by dripping coolant or chips that may stick to the tool – the intelligent filters employed by the DIGILOG technology simply remove the data generated from contamination on the tooling.

The machines for industrial parts production have BLUM workpiece touch probes as well as BLUM tool setting probes and laser measuring systems. Whether it is a tool or a workpiece that is being measured, the touch probes used at Benzinger exceed expectations. The high probing speeds that are possible, mean that measuring times can be kept very low. For workpiece zero-point referencing or the final component measurement, the TC52 touch probe can measure at speeds up to 2000 mm per minute without impairing the accuracy of the measurement. The tool breakage detection with the tactile systems can also be carried out at 2000 mm per minute.

In all applications, an additional advantage is that BLUM products  can be easily integrated into the Benzinger machines, despite the fact that they are capable of fulfilling very complex requirements. "With our machines, we test the limits in a number of aspects, especially where precision is concerned. Measurement in the machine is essential, especially to ensure stable machining processes," as Rainer Jehle summarizes. "Wherever we have a choice, we always go with BLUM products; our experience with them has been extremely positive. The fact remains that customer requirements are becoming increasingly challenging, so more and more measurement technology is being used in ever more complex scenarios." So, there's no doubt: At Benzinger they will continue to get better at 'tracking down the micron' ...