Welcome to the family

Holzleimbau Zischka in Böblingen is probably Germany's smallest manufacturer of glue-laminated timber. Only 800 to 1,000 m³ of glulam a year leave the workshop measuring 13 by 52 m. It goes without saying that these are mainly customized components. The family-owned company has acquired a special expertise in glulam arches which can be manufactured with a minimum radius of 70 cm. But Zischka can also do them quite large: He can finger-joint laminated timber of up to 30 cm width and generate up to 24 m long trusses with a cross section of 30 by 110 cm without block gluing.

Machines are like family

Ralph Zischka is the head of a family business with only five employees. In a business like his, machinery investments are thought over quite carefully. The machines have been around for quite some time, but they are impeccably maintained. "To us the machines become like family members over the years", says Zischka. The youngest of this family is the joining unit. The acquisition of such a machine has been in the air for years. But it was not until the Robot Drive was introduced to the market by Hundegger, Hawangen/DE, that Zischka saw all his requirements fulfilled: great flexibility, low space requirement and reasonable cost.

Joining? We do our own!

When strolling through the halls the impressive diversity of the products manufactured here becomes obvious. Some beams of pre-painted glulam for winter gardens sit next to glulam arches for a playground and laminated timber purlins. Zischka works strictly upon order. His customers are not only found regionally. In Kiel/DE Zischka’s products are used in buildings just as they are in Tokyo/JP and in Madagascar.
Every job is different. But one thing became apparent: More and more, customers wanted their joining to be done for them. More often than not, Zischka saw his laminated beams being transported directly to a joining center to be shipped on to the customer thereafter.
The desire to bring this added-value into one's own company is understandable. The joining unit therefore had to be suitable for all operations. Four- or five-axis machines, which can process roof trusses efficiently, would not suffice for Zischka. He needed a robot.

A six-axis robot arm – nothing else

The specification was: The machine must be flexible, small enough to fit into the hall and deliver impeccable quality work. Accomplishing joining projects in short periods of time, however, was not of foremost interest. These requirements virtually called for Hundegger’s Robot Drive. The basic operating principle has already been outlined (see links below).
Zischka ordered the machine for components up to 30 by 62.5 cm. These are conveyed into the machining zone via high-precision driving rollers. The compact machine performs all the processing steps with a six-axis robot arm which reaches all sides of the workpiece. From a changing station, the unit will always get the right tool for the next job. The 12 kW spindle reaches up to 12,000 rpm. Shavings and wood residues fall down while the wood component moves on horizontally.
Hundegger typically allows for modular upgrade of the Robot Drive. Automated stacking, an additional five-axis saw, marking or pressure units or a four-side planer can be added also at a later point in time. "I do not need those things", says Zischka. For him, joining projects are no bottlenecks. This job is a matter for the boss anyway. The master carpenter and graduate civil engineer has quickly made friends with the machine. More often than not, the joining is done after work when the employees have already gone off home. He likes the work as it is also a welcome alternation. "Doing the same thing all day long is not for me", he explains.

Three times faster … and better

During the conversation, the senior boss, Hans Zischka, comes to joins us. The broad shoulders and tanned hands of the 75-year-old tell of a laborious life. He took over the mill from his own father. There were lucrative years when Zischka produced church pews, which paid for the introduction of glue-lamination and brought extensive know-how in gluing to the company. With that, Zischka senior stands for a craft that changes as automation increases. But that does not bother him. He is a fan of the Robot Drive: "It works three times faster and more accurately than any carpenter could", he says.

Joining on an elevated level

Zischka’s glulam company was established in 1950. Over the years, the industrial area of Böblingen has grown to surround his company grounds. Room for expansion is rare. So the new machine had be integrated into the existing building. Even if the working zone of the Robot Drive is only 3 m wide, the roller conveyors before and after it measures 9 m and thus the whole unit is still too large. Zischka solved the problem by mounting the machine on stilts above the roller conveyor of the joining unit. The machining zone cabin would merely have had to cantilever by a half a meter. But that's easier said than done.
Even Hundegger suggested otherwise for fear of disrupting vibrations and initially did not want to take the chances (Hundegger always takes the responsibility to deliver a fully functional system). It took the intervention of company founder Hans Hundegger himself to realize the project. The podium structure was tested in Hawangen, it worked and so it was implemented in Böblingen. This kind of commitment of the owner himself impresses Zischka. "I was skeptical before, but now I am all for Hundegger.
" Now Zischka has his Robotic-Drive sitting on a structure of 1.2 m height and the machine practically does not take up any space at all. In addition, the removal of wood residues is much easier because everything falls to the floor. In- and outfeed of the joining components is also no problem. For the gantry crane it makes no difference whether it heaves the wood on a roller conveyor at 1.2 or 2.4 m. Yet structural changes at the building were necessary. The hall wall was opened because the six-axis robot arm extends up to 1,5 m to the rear. For this, Zischka built a wooden housing of his own glulam ceiling elements. By using roller blocks, the carpenter from Baden-Wuerttemberg can even machine his own glulam beams of up to 24 m length.

Got the hang of it in no time

As one does prior to the arrival of a new family member, Zischka did some intense preparation for his new Robot Drive. With the pre-installed CAD/CAM system “Cambium” he made himself familiar long before the system was delivered on 13 October. The start-up phase was a short one. Zischka quickly made friends with his Robot Drive – which he had painted yellow on special request. Since then he diligently executes joining jobs. Rod-shaped elements are no longer a problem. The joining machine is even used to machine arcuate elements.

Operational thinking into the future

The group photo shows three generations gathered. The 75-year-old senior boss, the 39-year-old entrepreneur and his 2-year-old son Moritz.
The little boy is also another reason why the Robot Drive was purchased after all. "If I am to inspire my son to follow me as my successor one day, then I must invest in modern equipment every now and then. Otherwise, he will miss the excitement of it”, says Zischka.

Holzleimbau Zischka – Facts

Established: 1950
Location: Böblingen/DE
Managing director: Ralph Zischka
Employees: 5
Production: Glulam up to 30 cm by 1.1 m, 24 m long, and curved (70 cm radius and higher), alternative wood species (larch, fir knotfree, oak, beech, pine, exotic wood), including joining