Handling & Robotics

Handling & robotics with innovative additive manufacturing technology from EOS

Automated handling devices and robotic systems often form the heart of industrial production. The gripper systems used must always be designed specifically for the product to be transported. The greater the variance of the products, the greater the need to adjust the gripper systems accordingly. In addition, the productivity of a production machine is often directly proportionate to the acceleration capability of the gripper systems. Lightweight grabbers thus play a central role in handling and robotic system applications.

 

 

The innovative Additive Manufacturing (AM) technology from EOS offers ground-breaking benefits in relation to the design and manufacture of gripper systems: The targeted use of materials means that even complex structures can be produced as stable lightweight components. The reduced moving masses have a positive direct effect on the achievable acceleration and therefore on the productivity of the machine. AM makes it possible to adjust the design of gripper systems very quickly if the product to be transported changes.

 

 

One of the particular strengths of laser sintering technology from EOS is the fact that functions can be integrated directly in components. Hinges, gripper mechanisms, air channels, mounts for sensors and other functions can be incorporated in the components during production. This makes it possible to dispense with additional assembly steps for many individual components, further increasing cost efficiency.

 

Case Studies

Redesigned handling device

A conventional handling device was redesigned leveraging the possibilities of laser sintering (4 slides)

Bionic handling assistant

Additive Manufacturing (AM) provides weight, flexibility and cost advantages for gripper

EOS Additive Manufacturing technology – Handling & robotics best-practice examples

Industry: Anubis 3D – 3D-printed end-of-arm for smarter packaging

An innovative, industrial, 3D-printed end-of-arm enables Langen Group to lighten the load on their customer’s robotic packaging line

New robots for the pick-n-pack line were already on order when the major American food produ

cer’s equipment supplier, Langen Group, began designing the end-of-arm tool that would enable the robots to pick up wrapped, stacked crackers and place them into cardboard boxes. The engineers than ran into a challenge: the tool had to be extremely light. What seemed to be almost impossible turned out to be quite easy by relying on additive manufacturing. Anubis developed a clever solution for the Langen Group using EOS systems.

 

Challenge

To achieve maximum speed without upsetting the center of gravity of the robots, the tool—plus the weight of the product itself – couldn’t weigh more than two kilograms. But the largest load of crackers on the line was 1.5 kilos for a ten-pack. That left only 500 grams with which to design the perfect tool. “Meeting these requirements would have been impossible with aluminum and sheet metal. To handle a heavier metal tool they would have had to reorder larger robots, which would have been more expensive—and they were also under extreme time constraints”, says Anubis president Tharwat Fouad.

 

Furthermore, the tool needed to be quick-release, quick-connect, so operators could change from one size to another without bolts and nuts adding assembly time. “In all, there were two completely different configurations, different shapes and three box sizes consisting of two small boxes at one time and one large box,” says Fouad. “They wanted a single tool that could handle it all, weigh no more than half a kilo, and they wanted it as soon as possible.”

 

As in case of previous projects, Fouad and his team spent some time looking at the market, evaluating which manufacturing technology would best serve their customers. “We found that most of the manufacturers that bought into plastics-based additive manufacturing did so for rapid prototyping,” says Fouad. “But our reasons were completely different. We envisioned a number of opportunities for functional, end-use components, and felt industrial 3D printing was the best technology for such applications.”

 

Solution

Once the decision to pursue additive manufacturing was made, Fouad performed a detailed analysis of the many different types of equipment available before deciding on a FORMIGA P 100 system from EOS. “Within a few days of delivery, EOS had us up and running. The system was quite easy to learn. EOS was there with us through it all, to the point where we became experts ourselves on the equipment. Now, several years later, we remain very happy with our decision.”

 

“The biggest challenge to additive manufacturing acceptance“, Fouad says, “is changing decades-old ways of thinking. The conversion from metal to plastic is possible, especially if it’s done scientifically. You need to focus on part geometry, and throw out traditional concerns over part complexity. EOS technology has no such constraints.“

 

Equally important to Fouad’s vision of end-use products was material selection—EOS powder-bed fusion technology utilizes engineering-grade polyamides, polystyrenes, thermoplastic elastomers, and polyaryletherketones, for example. “The system gives us the ability to build a virtually endless array of parts, using materials that are widely accepted in the industry,” Fouad says. It uses a powerful laser paired with precision optics to quickly and accurately produce parts. The laser beam hereby fuses the powder material layer by layer to produce highly complex parts.

 

The benefits of EOS technology quickly became clear. One of Anubis’ first successes was an end-of-arm tool for a blow molding application, which Fouad says inspired his team and opened their mind to what’s possible with plastic additive manufacturing. They’ve since designed a number of similar tools for injection molding and bottle packaging customers, as well as various brackets and supports, helping Anubis earn a name for itself as an innovator in these and other industries. As a result, the company has since purchased two additional systems from EOS.

Results

In the case of the major American food manufacturer job for Langen Group, instead of a more traditional metal vacuum plate and shroud (which would have taken months to design and manufacture), Anubis designed a lighter, streamlined set of components that provided four times the gripping force of legacy vacuum grippers. It took only a week to additively manufacture, assemble and test the new tool.

 

The material used for the main vacuum part was nylon 12 (PA 2200 material from EOS), chosen for its flexibility, ability to sustain crash loads, and because it is certified as USP Class VI approved for food contact. The wall thickness of the vacuum cup was between 2 and 3.5 mm and varied from section to section. The parts were designed specifically for industrial 3D printing with the help of a software program that optimizes the design of structures organically, following the lines of the geometry and adjusting the thickness as needed for strength and/or flexibility. “The efficiency of the redesigned profile we produced with EOS technology enabled the gripper to suck so well you could actually hang on it with your own weight,” says Fouad. “Our customer had never seen that level of performance before.”

 

The vacuum grippers were delivered to Langen Group and installed on the newly arrived robots at the food producer’s plant. “To design and produce tooling capable of picking what we wanted, while still staying within the payload constraints of the robot, would have been impossible before,” says Langen Group Engineering Manager Robert Husnik. “Due to the freedom provided by plastics additive manufacturing, we can now do the impossible.”

 

“I tell people that, unlike traditional manufacturing, complexity is free with additive manufacturing,” Fouad says. “A designer can come up with all sorts of wild ideas and no one will complain. You can reduce part weight, maintain st

rength, and deliver nice looking products with greater functionality, in less time and at lower cost than ever before. It’s a real manufacturing shift.”

 

 

 

 

 

 

Short profile

Anubis 3D is a division of Anubis Manufacturing Consultants Corporation. The company is based in Mississauga, Ontario and specializes in custom digital manufacturing such as industrial 3D printing.

Industry: Festo – Additive Manufacturing Enables Automation Specialist to Design its Bionic Assistance System

Additive manufacturing offers new design solutions for a more economic small batch production

Biological processes, motion patterns of living organisms or physical construction principles: Nature ha

s countless solutions only waiting to be analysed by bionic science and translated into technological innovation. However, it is difficult to employ conventional manufacturing techniques to make use of the solutions which Mother Nature has developed in millions of years of evolution. Festo, a worldwide leading supplier of automation technology, uses the laser sintering process for the small batch production of some of its industrial applications which are based on bionic adaptation. In 2010, the company’s Bionic Handling Assistant was awarded the „Deutscher Zukunftspreis“ (German Future Award), the technology and innovation award endowed by the Federal President.

Challenge

The Esslingen-based company has been gathering experience in additive manufacturing since 1995 and is now using this technology to produce several thousand parts per year. What began with concept models and functional prototypes has meanwhile developed to the level of batch production. The Bionic Learning Network, a group of renowned universities, institutes and development companies established by Festo in 2006, has made a substantial contribution to paving the way, since the technical principles of products which are derived from nature often have rather complex designs. Implementation by means of conventional manufacturing methods is impossible or difficult and always expensive. The production method determines the design of the product which all too often leads to design restrictions. Nature’s efficient construction principles, on the other hand, are not subject to such restrictions. Therefore, nature can be emulated only by a technology in which the design determines the means of production and which will ideally work in serial production as well.

 

Solution

One example of successful product development and production using additive manufacturing is the DHDG adaptive gripper. It has become an inherent part of Festo’s production range and is manufactured on a FORMIGA P 100 supplied by EOS. Its structure is adapted from a fish fin and has two flexible bands which form a triangle to converge at the top. Intermediate webs are connected to the bands via joints at regular intervals. This flexible yet stable connection allows the gripper fingers to precisely adjust to the contour of the workpiece. Even sensitive objects or objects with varying contours are gripped and transported. The particular feature is that the gripper elements already have this functionality directly after production and not only after expensive assembly procedures. That said, laser sintering is an underlying manufacturing requirement for this design and this specific application — and there is no alternative yet. Another example is the Bionic Handling Assistant. The flexible assistance system, which is modelled after an elephant’s trunk, consists of three basic elements for spatial movement, a hand axis and a gripper with adaptive fingers. „Its functionality and its structure that incorporates complex plastic components make it impossible to produce the hightech arm without laser sintering,“ says Klaus Müller-Lohmeier, Head of Advanced Prototyping Technology at Festo AG & Co. KG.With a FORMIGA P 100, a complete handling assistant can be manufactured in just four building sessions.

Results

The EOS technology makes it possible to directly incorporate functions that the final product is supposed to have. This is advantageous, since it reduces the number of parts and the additional assembly costs. „Thanks to the design freedom the laser sintering process gives us, we can manufacture movable, flexible but also specific rigid shapes — just as they occur in nature. Our designers can work without having to observe the restrictions of conventional manufacturing techniques and fully concentrate on the implementation of the natural principle analysed, “adds Müller-Lohmeier. Moreover, the DHDG adaptive gripper is very economic, because it is about 80 % lighter than conventional grippers made of metal. The reason for this is the additive manufacturing of plastics which allows the production of especially light-weight, elastic but very strong structures. Studies have shown that the gripper elements can withstand more than five million bending cycles. Additive manufacturing production always means tool-less production. „How cost-efficient this can be is illustrated by a customer project in which we have manufactured 12,000 components using laser sintering as an alternative technology. Tool-less production saved 40 % of the unit costs compared to injection moulding. All parts were finished within one week in just four jobs. Conventional production would have taken two months,“ explains Müller-Lohmeier. Moreover, follow-up costs for auxiliary materials and devices are reduced and there is no delay occurring due to the production of tools. This enables Festo to launch its products much faster. The high-tech robotic arm is one example of how a mainly digital process chain is implemented in industrial manufacturing. Müller-Lohmeier adds: „At the moment, we are also using the EOS technology more and more for projects that only call for limited annual quantities of a complex part. In such cases, the process is a real alternative for us to existing, often tool-based methods.“

 

Unpacking of Bionic Handling Assistant: The gripping device is already functional even right after production (Courtesy of Festo AG & Co.KG).

Unpacking of Bionic Handling Assistant: The gripping device is already functional even right after production (Courtesy of Festo AG & Co.KG).

 

„Laser sintering was the only process that made it possible to produce the Bionic Handling Assistant and its gripping element, the DHDG adaptive gripper. Due to the complexity and integrated functionality of the components, there is no alternative way of production.This process enables us to adjust the DHDG adaptive gripper to the specific application and is thus already used by customers all over the world.“

Klaus Müller-Lohmeier, Head of Advanced Prototyping Technology at Festo AG & Co. KG

Short profile

Festo is a worldwide leading supplier of automation technology and is thus recognized as the performance leader in the field of pneumatic and electrical automation thanks to its innovations and expertise in solving problems.

Address

Festo AG & Co. KG

Ruiter Strasse 82

73734 Esslingen – Berkheim (Germany)

www.festo.com

Industry: Wittmann Group – EOS additive manufactured lightweight grip system with integrated functionality

Bronchial Gripper with functional base plate made lightweight and durable with EOS technology

The hand is one of the defining stepping stones of human evolution: with its thumb opposing the other fingers, the human hand is an ideal tool for gripping, exploring, and working. As such, it is the key to cultural activity and t

echnical progress. Industry often exploits this ingenious principle: one of the processes for which machines are used is the automated gripping of almost any desired part for transporting to the next operational step.

 

Such gripping machines are masterpieces of engineering. Kuhn-Stoff GmbH & Co KG has dedicated itself to specialized engineering through the application of EOS Additive Manufacturing technology. The process entails the formation of machine parts, layer by layer, from plastic powder that is melted with a laser beam. In this way, Kuhn-Stoff has developed and produced an extremely lightweight, strong, and durable bronchial gripper for Wittmann Robot Systeme GmbH, in Nuremberg, Germany. Four of these grippers sit on a support frame with integrated pneumatic ducts.

 

Challenge

The customer is a manufacturer of robots and automation systems. Kuhn-Stoff was asked to re-design a mechanical gripper that raises, transports, and then sets down machine parts from a production machine via a pneumatic mechanism. The following requirements were established: the gripper should be lighter than its predecessor, while still being capable of moving the required loads. The complexity of the design should be simplified and the part must be able to satisfy efficiency criteria.

 

The significance of the weight comes down to physics: grip systems such as this must work quickly in order to move as many machine parts as possible within a given unit of time. The fact that mass is inert means that force must be applied to set it in motion – the heavier a load is, and the faster it moves, the greater the forces necessary for both acceleration and deceleration. Quite apart from the viewpoint of energy efficiency, this fact also has particularly negative consequences on the durability of the system: the greater the forces in play, the higher the wear on the machine.

 

The previous version of the gripper was made from aluminum, rubber tubes, and multiple connecting elements, and was expensive to produce. The layer manufacturing experts from Kuhn-Stoff set themselves the goal of significantly simplifying the design. The new structure of the machine part should contribute to a portion of the weight reduction. Another portion should be arrived at through structural optimization of the remaining parts – one of the central advantages of Additive Manufacturing. As work began it soon became clear that the new gripper could be produced as a single piece, without the need for post-production finishing or further assembly.

 

Solution

The team from Kuhn-Stoff began by examining the functionality and working requirements of the gripper: when compressed air flows into a flexible membrane, the claws of the gripper will open; likewise the system closes when the compressed air is turned off. In addition to the plastic’s flexibility, the part should be able to swivel through 90° to carry out the necessary motion sequence. Taking these requirements into consideration, it was possible to reduce the necessary number of parts to just two components.

 

With the completion of the design process, Kuhn-Stoff began work on the production of the new grip system using a FORMIGA P 100. In just a few hours the two components of the grip system were produced from polyamide. Thanks to EOS technology the pneumatic ducts and connectors were fully integrated in the base plate.

“As usual, production using the EOS system was smooth and problem-free. The end result, once again, impressed all those involved. In a single process step we were able to create a functionally integrated part that exceeded all of the requirements of the client. In short: Additive Manufacturing is now an every-day reality, but the results are still extraordinary,” says Hannes Kuhn, CEO at Kuhn-Stoff GmbH.

 

Results

In terms of the major goal of weight reduction, Kuhn-Stoff achieved an 86% drop to just 220 g. Despite its light weight, the gripper is still able to carry the necessary loads, even in demanding, continual usage: after 5 million cycles the team halted the stress-testing, having reached the designated service life. Over this period, not a single defect or failure occurred. The reason for this is the strength of the construction, which was achieved despite the air ducts integrated in the base plate. In addition, the flexible design ensures that, should small collisions occur, these do not result in any damage to the gripper system or the injection-moulding tool. In some cases, the lighter weight also enables the use of a smaller robot type leading to significant cost reductions. In addition Wittmann have been able to increase the number of working cycles due to the low height of the gripper which reduces the necessary opening width of the injection-moulding machine’s clamping platen. The bottom line is a reduction in operating costs. Manufacturing costs have been reduced by 50% compared with the conventionally manufactured predecessor. This is due to weight savings as well as the reduction of the number of components from 21 to two. Equally important is the short production time: the grip system, which previously took Kuhn-Stoff twelve days to manufacture, now requires just three.

 

“We are extremely happy with the new grip system. It has proved itself to be just as effective in heavy-duty, continual use as the previous unit, yet is cheaper and lighter and can be produced more quickly. I have never seen as significant an advance in grip manufacturing as that which Additive Manufacturing has brought to the production of our bronchial gripper. The production method has had a very positive effect on our automation solutions,” summarizes Michael Tolz, Head of Technology and Branch Manager at Wittmann Robot Systeme GmbH. Occasionally revolution can have its advantages over evolution.

 

Integrated functions: when compressed air flows into a flexible membrane the claws of the gripper will open; likewise the system closes when the compressed air is turned off (Source: Kuhn-Stoff).

Integrated functions: when compressed air flows into a flexible membrane the claws of the gripper will open; likewise the system closes when the compressed air is turned off (Source: Kuhn-Stoff).

“We have been using EOS technology for more than eight years and have had exclusively positive results. When applied correctly, the design flexibility offers significant benefits that can give our customers almost unrivaled advantages in the marketplace.“

Hannes Kuhn, CEO at Kuhn-Stoff GmbH & Co KG

“We have been deploying parts constructed using Additive Manufacturing across various sectors of automation for years. The bronchial gripper meets all of our requirements – surpasses them in fact. The part is very reliable in terms of its everyday performance.”

Michael Tolz, Head of Technology, Germany, and Branch Manager at Wittmann Robot Systeme GmbH, in Nuremberg

 

Short profile

Kuhn-Stoff GmbH & Co KG is one of the first companies to utilize e-Manufacturing from EOS for specialist engineering. Since 2005 it has convinced its customers of the benefits of polyamide parts produced by Additive Manufacturing. Kuhn-Stoff delivers to many leading companies and is focussed on fully exploiting this technology’s advantages.

 

With 7 production facilities and 20 branches, the Wittmann Group is represented in all of the world’s major plastics markets. Its goal is to provide decisive advantages for plastics processing through the seamless integration of processing machines, automation and peripheral devices.