Georg Willmann is a model entrepreneur – energetic, grounded and passionate about innovation. In the space of just 25 years, he has harnessed these traits to build up what is now one of Germany’s 20 biggest turning shops in Löffingen, in the south of the Black Forest region. WST Präzisionstechnik GmbH currently has 650 employees who work on 250 turning, milling and grinding machines to manufacture precision parts for the automotive industry and other sectors. WST also has a second plant in Hüfingen and a site in the USA.

Around seven years ago, WST decided it needed to automate some of its handling processes. A number of processes were identified as activities that should be carried out by robots, such as removing machined parts as well as other downstream steps such as cleaning, deburring, laser engraving and measuring. That would mean automated turning machines the company already had could then be left to run without supervision. 

Willmann appointed design engineers and other staff to develop and build the bespoke solutions, and this team has since become a subsidiary in its own right – Black Forest Smart Automation. The first staff members included Waldemar Klan, team leader in engineering, and Martin Rudolf, head of engineering, who started with factory equipment engineering and laid the foundations for the automation technology. All in all, there are 22 experts at BFSA covering all areas from sales and production to assembly and services.

Gaining extra production time

“When using our systems, machines can be left running unsupervised, for example overnight or at the weekend,” says Christopher Mayer, head of sales. Combining the systems with a bar loader, for instance, frees up extra production time without having to deploy additional staff. “As a result, our systems often pay for themselves in six months to a year. There are currently 65 of our systems in use at our parent company WST alone – you could say it is our main showroom. At the same time, we can also prove the reliability of our systems there,” explains the manager.

The ingenious details that BFSA incorporates into its solutions are particularly striking. For example, on one particular Haas machining centre, the robot has to reach very deep inside the machine compartment to remove the finished part. Instead of using a bigger robotic arm, which would have generated bigger inertial forces, the arm was mounted on a linear axis so it can travel along this axis and into the machine compartment to remove parts.

A turning device has also been attached at the front of the linear axis that opens and closes the machine vice in the machining centre to allow the removal and insertion of parts. A patent has already been awarded for this “intelligent” vice. In other solutions, the values from component measurement, which is carried out in the BFSA cell, are used to amend machine parameters. This means that a tolerance of 15micrometres can be reliably maintained in turning operations, even when the machine heats up and cools down. As a result, an entire machining step in a grinding machine can be omitted, which not only saves a lot of time, but also cuts down on additional handling and costs.

Always the perfect fit  – Compact and mobile

Sabine Machlitt, head of procurement at BFSA, sets out additional features that make the systems really stand out: “Firstly, they are compact, with most systems having a footprint no larger than a Euro pallet, which even the tightest production workshops can accommodate. Secondly, they are mobile and can be rolled to one side to make way for work on the machine. And, last but not least, our systems look good because they are integrated into an enclosure and therefore have a very sleek, clean outward appearance.”

So what led to this unusual use of enclosures in mechanical engineering applications? “I’d long had the idea of installing robots in enclosures,” recalls Markus Pfeifer, inventor and head of programming. “We were able to turn that idea into a reality at BFSA. Instead of using a heavy machine base to carry the robot and enclose it to protect its working area, we use standard enclosures. We chose Rittal as a supplier not just because the company makes the best enclosures, but also because it meets our needs quickly and without any fuss.”

The advantages don’t stop there though: “From the door with its elegant handle to the fixings on the side and rear panels, the build quality of the enclosures is outstanding.” The design also features ingenious gusset plates and reinforcements that ensure the enclosures are rigid enough and can withstand the inertial forces generated by a handling robot.

Cleaning in enclosures

The Rittal VX25 standard bayed enclosures used at BFSA can be combined as part of a modular concept. For instance, there is a cleaning station made up of three enclosures that are bayed in a U shape. Finished parts are taken out of the turning machine, cleaned to remove all particles larger than 300 micrometres and then finally placed into trays. Once full, the trays are packaged while still in the enclosure, before there’s any chance of the parts picking up any dirt or particles again. This is where BFSA is making the most of the IP55 protection category that the enclosures come with as standard to ensure they are air-tight and dust-tight.

Other solutions incorporate a laser station, where parts are labelled with a data matrix code (DMC) once they have been measured. In this application, it is crucial to ensure the laser beam is contained within the station at all times. Rittal enclosures can do just that, too, and have the relevant certifications to prove it.“One major advantage of the enclosures is the comprehensive certifications they come with, which we can use for our own CE declarations of conformity,” explains Pfeifer.

“These cover everything from lightproof qualities and air-tight seals to the mechanical strength of the side panels and doors, which makes it easier for us to present evidence relating to the mechanical protection of the robot’s working area.” In the lower section of the main enclosures, BFSA fits another, smaller AX-type enclosure from Rittal, where the station’s entire control system is installed. The door on the large enclosure has a cut-out section so operators can access the operating elements of this control system without having to open the door. BFSA supplies Rittal with the relevant STEP files for making additional cut-outs in doors and side panels, which is done by laser cutting before the enclosures are then painted black.

Pfeifer is also impressed by the accessibility of the enclosure: “You only need to remove six screws to take the rear panel off and the double swing doors let you open up the whole of the front.”The programmer is very happy with the company’s collaboration with Rittal: “Rittal is always able to deliver and we get the modified enclosures within six weeks, painted and complete with the cut-outs we’ve requested.”

Recalling how things used to work, Pfeifer really appreciates the current approach: “At first, we built our solutions in a conventional way, on a welded machine base and with a cover made of profiles, plates and plexiglass. That meant we had to buy in lots of different components for the enclosures from lots of different suppliers, which involved a great deal of procurement, logistics and bookkeeping work. With Rittal, I buy exactly one enclosure and that’s it – job done. That easily provides a time saving of 20 per cent and more. The modularity of the solution gives us more freedom during the design process and allows us to create solutions that are more innovative and – thanks to the certifications supplied with the enclosure – are quicker to document, too.” In this case, thinking outside the box to put automation solutions inside a box has really paid off, as Machlitt sums up: “Switching to Rittal has not just made the systems look nicer – they’re also lighter.

The castors on the enclosures mean a cell can be moved from one machine to the other and the system can gradually grow. That is another benefit and a step closer to our goal of being able to offer automation solutions that are suitable for smaller companies, too.”