Open to new ideas
C 650 | C 400 | RS 3 | Hohner | Entry into contract manufacturing
Hohner Maschinenbau feels at home in the world of complexity and precision. So why not expand this know-how and erect another business pillar as a subcontractor? Thanks to two robot-automated 5-axis machining centres from Hermle, the German machine manufacturer is optimistic about taking this decisive step forward.
No flyers, no theatre brochures, no menus – it has been somewhat quiet in print shops over the past year. This also has had an impact on companies that develop machines for the graphics industry, such as Hohner Maschinenbau GmbH. During this difficult period, the family-run business from the southern German town of Tuttlingen decided to invest in two 5-axis machining centres from Maschinenfabrik Berthold Hermle AG, automated with the most powerful robot the Gosheim-based company has to offer. Hohner is thus entering the subcontracting sector and erecting a fourth business pillar – independent of the printing industry.
Hans-Peter Schöllhorn, CEO of Hohner Maschinenbau GmbH, gives an elaborate explanation of the firm's journey from wire stitching to subcontracting precision parts: "Since the 1950s, we have been strongly involved in the graphics industry. On the one hand, due to our own systems for print finishing, the saddle stitchers, and, on the other hand, as a manufacturer of narrow stitching heads, which we supply to OEMs worldwide." Added to this are the wire stitching machines – a third important line of business that has allowed Hohner to become more independent of the classic printing industry. "Staples are used everywhere, from brochures, masks and tea bags to sustainable six-pack packaging. They ensure a reliable join and are easier to recycle than adhesives, for example," Schöllhorn explains.
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Hohner Maschinenbau GmbH has invested despite the Coronavirus crisis: The C 650 U and the RS3 robot have been in operation since November 2020. In March 2021, the C 400 U was added to the system. -
A look at the finished housing components for the narrow stitching heads proves that Hohner can manufacture components with complex geometries. -
In addition to cast iron, plastic, aluminium and steels, Hohner Maschinenbau also machines brass on the C 400 U and C 650 U. -
The RS 3 robot reliably loads the two 5-axis machining centres from Hermle, even in unmanned shifts. -
Machine operator Samuel Emeka checks a die, with finished components for Hohner's narrow stitching heads. -
Depending on the material and component size, the machining time is between 15 minutes and three hours.
Personalised printing
Even before the Coronavirus crisis, the graphics industry had been under a lot of pressure: The Internet has grown into a strong communication platform with a myriad of distribution channels. Individual user targeting, for example through re-targeting, makes the online world highly attractive for marketing strategists. But with the arrival of digitalisation, the classic printed product is picking up on the trend towards individualisation – print is becoming more personal. Hohner has been working on solutions for digital processing in parallel to its classic saddle stitchers for some time now and has recently combined both worlds into one system. "In addition to personalised brochures or magazines, our customers also need to be able to produce ever smaller and more varied runs. We have, therefore, designed our latest machine in a modular fashion," says Schöllhorn. "A core can be expanded with up to five feeding variants. From saddle stitchers to a crossfolding, tower, fold stitcher or digital module. The press actually grows with the needs of the print shop."
The issue of customising also applies directly to Hohner's own products: "We used to produce high quantities of the same type. Today, each system is individually adapted to the customer's needs," the CEO explains. The challenge was adapting production to smaller quantities without impacting productivity. Schöllhorn reorganised the machinery and looked for a solution to increase productivity. His plan was to reduce the vertical range of manufacture and only machine the high-value drawing parts with special quality requirements internally – ideally 24/7. This is where Hermle came into play.
24/7 precision
“We needed a system that combines the highest levels of flexibility with a maximum degree of automation," claims Andreas Hennemann, production manager at Hohner Maschinenbau GmbH. The requirements for handling and machining a range of parts in various dimensions, including various devices, were met by a combination of C 650 U and C 400 U. "The two machines complement each other perfectly, since our range of parts is immense. We mill cast components, plastic, brass, aluminium and steels in dimensions of up to 900 millimetres. On average, however, our workpieces measure 300 millimetres, for which the C 650 U would be too big," says Hennemann when illuminating the decision-making process. The machining time is between 15 minutes and three hours, the number of pieces between five and 500. A powerful robot is positioned between the two 5-axis machines and loads them fully automatically and autonomously. "The RS 3 can handle parts weighing up to 420 kilograms, making it the best possible option for our application," adds the production manager.
The robot as well as the larger of the two 5-axis machines have been in operation since November 2020. "This type of system requires a team with an understanding of digital principles. Our staff are open minded about cutting-edge technologies and simply enjoy tackling new challenges," says Schöllhorn. Hermle installed the C 400 U in March 2021. Here, too, everything went to plan, Hennemann confirms. "We have known Hermle for decades and have worked together for a very long time. Further, we have placed our full trust in Hermle from the start. We were once again impressed with the service and the technology provided," says the CEO when praising the cooperation. His plan has worked: "The machines run perfectly. Productivity has increased from 30 to 80 per cent. The third unmanned shift and the weekend shifts now operate at 80 or 50 per cent capacity. And we will continue to expand this capability."
Four less
The Hermle C 400 U and C 650 together with the RS 3 robot replace six existing systems at Hohner. This shows that Schöllhorn was not necessarily concerned with expanding capacity but with increasing productivity. In addition, the machine manufacturer is exploring new manufacturing dimensions, as the CEO notes: "Now we can offer the precision that was difficult to achieve before." And Hohner knows what precision means: In a small stitching head, 160 parts complete 18,000 cycles an hour. If a surface is not manufactured to an accuracy of one hundredth of a millimetre, it will not run smoothly. "We know everything there is to know about our own parts. We take complexity and difficulty in our stride. That's why we want to offer this know-how to other companies," this is how Schöllhorn explains entry into the world of subcontracting and adds: "I don't see the point in filling a highly qualified system with parts that I can procure more cost effectively somewhere else. We'd rather manufacture complex and highly demanding parts on the Hermle machines for internal and external use."
For him, the investment has had another advantage far beyond productivity and efficiency – it sends an important signal: "A company that is geared towards cutting-edge technology also has more chance of attracting future apprentices and skilled workers. It shows that we are a crisis-proof and future-oriented company."
