Small investment with a big effect

In keeping with its company slogan of 'Small investment – big effect', automation specialist Weiss GmbH brought eight machine tools 'up to speed' with the help of innovative clamping devices from Hainbuch. Headquartered in Buchen, Germany, Weiss GmbH is a specialist in the development and manufacture of high-precision rotary indexing tables and automation technology components.

To bring its machine tools up to speed, the company employed Hainbuch work-holding technology and this drastically reduced set-up and machine idle times whilst simultaneously increasing precision and process reliability. As the Director of Tool Management at Weiss, Mr Thomas Schuster explains: "The product development in recent years has forced us to completely rethink our manufacturing processes with the aim of reducing set-ups and machine downtime."

With massive worldwide growth, the company is working on comprehensive capacity extensions. Reviewing a milling operation on drive or transport cams where rotary index tables are the centre of the process, the company demanded soft, jerk-free and impact-free movement with a long product life. As Mr Schuster continues: "We had to reduce set-up and idle times through optimised precision and shorter machining time. We felt that Hainbuch could support us in this endeavour".

Retrofitting project

Looking for new clamping device solutions, Mr Shuster visited Hainbuch at the EMO exhibition and this initial contact proved promising. The large retrofitting project required the upgrading of eight older machine tools with high-precision clamping devices that demonstrate a high repeatability, high holding forces and short set-up times as a necessity.

Analysis of the clamping situation

Together with Hainbuch Regional Sales Manager, Joerg Tittel, the existing clamping program of conventional 3-jaw chucks was promptly analysed and appropriate alternatives were found. The result was the introduction of customised clamping devices for the eight machines.

For the smaller machines the main benefit was not just the shorter clamping set-up time, but also having the ability to use new tools from Mitsubishi Materials (MMC) due to the high holding forces of the Hainbuch chucks. For larger machine tools, the most significant factor was the massively reduced set-up times. Thus, the complete package of innovative clamping devices and a more effective quick change-over fixture paid for itself within a very short period of time.

The Toplus clamping system was implemented to ensure optimal precision with high clamping forces. The Centrotex quick change-over system was also integrated into the manufacturing process to ensure quick change-over of the numerous component types. The use of Mitsubishi cutting tools and the consequent change to cutting parameters was not a requirement imposed on Hainbuch. However,  with Mitsubishi Materials cutting tools given a more rigid, robust and sturdy machining platform through the Hainbuch products; Weiss GmbH could optimise the potential of its cutting tools and yield better results. Credit to the stable and precise platform provided by Hainbuch, the cutting tools operated at higher speeds and feeds, tool life was enhanced and surface finishes were also improved.

Optimal metal removal rates

The large transport cams manufactured by Weiss GmbH are soft machined with indexable insert tools. The high clamping forces, the stability and the precision of the Hainbuch chucks enable optimal metal removal rates. Viktor Gruslak, Acting Department Manager responsible for cam milling recalls: "With the old fixtures we had set-up times of between two and three hours for a complete conversion. Now, the overall time is between 10 to 20 minutes. We still have to align the tailstock the changeover time of the Hainbuch chucks takes only five to ten minutes. This is a huge saving."

Asked whether clamping device providers other than Hainbuch were contacted, Schuster responds: "At that time, we were extremely thorough in looking over the offerings from all possible vendors at EMO, but the Hainbuch solution was the best suited for our parts."

On his first walk-through of the manufacturing facility, Hainbuch Regional Sales Manager Mr Tittel comments: "We immediately recognised the potential impact that our products could make and to reinforce this we conducted practical trials. When a 3-jaw chuck was replaced with the Hainbuch system, the machine operator said: "Often you do not trust yourself to increase feeds and other metal removal rates to the levels that the new clamping device allows. An operator is often limited by the pressure of the clamping hydraulics, but even when testing the machine and tools to the limits, the clamping device still had more to offer."

Better workpiece quality

Mitsubishi Application Technician Ullrich Jüngert adds: "With this application two lucky breaks came together. We have a higher clamping force and rigidity. This allows us to apply an IMX-series end mill cutter, a milling system with interchangeable cutting head and a carbide shaft that ensures high accuracy. With this combination it was also possible to reduce machining times by half in some cases.”

Schuster summarizes more than a year of operating experience: "A project such as this can only be executed with reliable partners. Partners who like ourselves also focus on involving the employees. By implementing the new Hainbuch systems, we are saving 15 minutes of set-up time for every single part. This is one hour per shift saving that wouldn't have been possible without Hainbuch." The only effort involved for Weiss was adapting and integrating the clamping hydraulics in the controllers, in order to clamp and unclamp hydraulically.