Figure 1:
Two or three-jaw grippers in either angular or parallel configurations.

Figure 2:
Mounting Chuck.

Figure 3:
Pneumatic and vacuum cup systems.

Figure 4:
Tubular framework system.

Figure 5:
Lightweight aluminum adjustable system.

 
Figure 6: Kits.

By Trent P. Fisher, P.E.  >SAS< Automation, LLC

In the early 1990s, the robot revolution really arrived in the United States. New orders of robots soared 40 percent and suddenly automation became the hottest topic in all aspects of manufacturing. And, while cost-effectiveness and reducing manufacturing costs were considered key automation objectives, the biggest challenge that led to the evolution of robotic end-of-arm tooling was that flexible automation also had to guarantee product quality. 

Before this, manufacturers paid considerable attention to the robot specifications and little attention to the end-of-arm tooling. As a result, they ended up with inflexible tooling systems that either weighed too much, took up too much space or just didn't work. The tooling was custom built and expensive. And only robot manufacturers were trusted to build it, although their primary attention was clearly on the robot. 

Initially, this tooling included flat machined mounting plates, special mounting brackets, generic pneumatic grippers and components. And you had to go to several places because no single source offered complete tooling systems. Generally, non robotic industrial equipment suppliers would make varied pieces and parts. 

Another problem during this era was that the tooling considerations were often left as the last stage of automation to be planned, often leading to involved and costly design time and re-engineering of tools and parts. 

Guaranteeing Product Quality

When U.S. manufacturers finally adopted the challenge that automation also had to guarantee product quality, they were forced to evaluate their end-of-arm tooling as an integrated part of the automation process.

Finally, manufacturers realized that if the tooling fails to adequately locate a part, release a part or, worse, drop a part, the results are productivity downtime and damaged tooling and parts. In addition, many production processors run most efficiently when cycle time or line speed runs consistent with a robot and dependable gripper. For the first time, a robot became only as good as its end-of-arm tooling. 

End-of-arm tooling became respected because if the tooling couldn't grip, hold, locate, inspect, move, lift, release and handle the part in a repeatable fashion, then product quality could not be guaranteed. It became clear that the EOAT could make or break the production process. And, as processors began using robots for handling of all kinds of parts (from big and bulky to small and intricate), the need for fully adjustable, lightweight and very custom EOAT became apparent. 

New EOAT companies emerged and robotic companies began developing EOAT departments. A few companies began providing off-the-shelf components; some also offered custom designed work. The capability to design and build complex EOAT emerged at this point. New companies accepted the challenge that their focus needed to be on enhancing the performance of the robot. 

From Custom to Modular Systems

As robotic technology advanced and manufacturers became more comfortable using robots in all areas of production, they also became familiar with the EOAT design process and even made their own tooling. Off-the-shelf components allowed manufacturers the opportunity to build their own EOAT successfully or gave them the option to contract the tooling to experts. At long last manufacturers had options in not only the level of tooling, but also in who could provide them. 

As applications for robots expanded, the realization that EOAT grippers should be more specialized, the system approach rather than custom tooling evolved in the industry as an integral part of automation.  Companies already in grippers enhanced their offering in style and type, focusing on the gripper itself -- such as two or three-jaw grippers in either angular or parallel configurations (see figure 1). Other companies and suppliers focused on the framework and/or the mounting chuck or interface with the robot (see figure 2). Still others focused on pneumatic and vacuum cup systems (see figure 3). 

Adjustability is Key

In some cases, the result for the EOAT framework was a tubular framework system (see figure 4). The tubing system has evolved into a widely used and accepted configuration in many applications. Hybrids of the tubing system also emerged; these are combined with a lightweight, sturdy aluminum extrusion mounting base, specially designed to ensure adjustability, yet remain secure and tight in dynamic robotic applications. Individual gripping components such as vacuum cups, locators, grippers, fingers, and tubular systems mounted onto the extruded aluminum base also emerged. The result was an extremely rigid, lightweight adjustable system (see figure 5). >SAS< has developed this concept into a fully developed, integrated modular system, offering more than 1,000 components available off-the-shelf, with everything from robot mounting chucks, special aluminum frame sizes, standard tubing or shaft sizes, to grippers, pliers, and vacuum cups. All are designed with modularity, adjustability and value in mind, available individually or in kit from (see figure 6). 

Now and the Future

Now, fully modular and adjustable EOAT is continually being examined for design improvements. Look for continued advancements in design and durability and EOAT made out of lighter-weight materials. EOAT, not for merely picking and placing anymore, will be expected to perform more complex tasks. 

The next generation of EOAT will pull, cut, insert, apply, package and inspect, as well as integrate with upstream and downstream equipment. Now, the important points being considered as part of the robotic EOAT automation process are:

• Automation cell and system performance requirements
• Robot payload capabilities
• Availability of replacement parts
• Flexibility requirements and overall automation plan
• Adjustability as a requirement for part or cell layout changes
• Affordability in not only the up-front cost, but also speed in layout
• EOAT design time, to meet the ever shrinking time from design to production prevalent in many industries, especially automotive. 

Manufacturing challenges will advance all phases of robotic automation which in turn will drive advancements in end-of-arm tooling performance. EOAT will be looked upon to reduce manufacturing costs through easy-to-use component-based systems, reduce labor costs with EOATs that are handled and designed quickly, advance the technological level by processing parts that are increasingly complex, all while guaranteeing part quality by being able to adequately grip, lift, locate, move, pull, cut, insert, apply, package and inspect through the entire production process, consistently. 

EOAT companies will drive advancements that will make your robot do more, and you do less. After all, your robot is only as good as it's EOAT. 

Trent P. Fisher works for >SAS< Automation LLC in Xenia, Ohio. He can be reached at 937-372-5255. 

Reprinted with permission from RoboticsWorld, June 2001. Published by Douglas Publications,