By John Westbeld
Engineering Manager
SAS Automation, LLC.

End-of-Arm Tooling (EOAT) or end effectors can range from a simple vacuum cup tool to a tool with multiple actuators and custom details. The complexity of the tooling depends upon the workpiece / part (referred to as part from here on) characteristics, the environment, fixturing interface, and part manipulation. Applications range from a simple pick & place application to a multiple part assembly cell with multiple EOAT. Ultimately your robot's performance depends on the reliability of the EOAT.

EOAT Basics
Prior to developing any EOAT - you will need to understand the payload of your robot as well as the weight of your part. Straight forward pick and place applications usually have straight forward EOAT made of modular EOAT components with possibly a few custom details. The robot is doing all of the part manipulation and the EOAT is there strictly to secure the part. Standard off-the-shelf EOAT components are available for building these types of tools. EOAT suppliers can assist you on component choices so you can build the EOAT yourself and save money. Standard components include robot mounting plates, frame profiles, clamps, arms, cups, grippers, fingers, fittings, and tubing. Once you build 1 or 2 simple EOAT you will quickly learn how the components from modular systems go together.

Advanced Considerations - packaging & palletizing
Difficult to hold parts and parts needing additional manipulation or secondary operations require a custom tool. Uncommonly shaped parts such as spheres require special tools. Often environmental changes as well as handling multiple parts require special attention. IML (in-mold labeling) is also another common application for multifunctional tooling. By adding motion or functionality to the EOAT - you often can reduce the need for secondary operations or even an additional robot. Sometimes standard components can be used in conjunction with a few custom details to add the functionality needed. Simple part manipulation such as linear movement and rotation can be accomplished with custom mounting plates and standard actuators.

For example if you need to secure two or more bottles with one EOAT and had to adjust their center to center spacing before you placed the bottles down, you could do that with linear actuators. If you needed to pick up two or more lids and place them on the base of your product and needed to rotate one of the lids 180 degrees before placing it you could do that with a rotary actuator and custom mounting. Custom tools are particularly useful in packaging and palletizing applications due to the number of operations required: secure unsealed boxes, securing of the pallet, palletizing the cases with restrictions on spacing to ensuring that fragile cases are not crushed.

Work Cell Restrictions
There are applications where standard EOAT components will not work due to part or robotic work cell restrictions. In these cases you have to design your EOAT around the constraints of your work cell. The first thing to look at when designing custom EOAT is how to secure the part or parts. Some of the methods used to secure parts include vacuum, standard grippers with custom jaws, custom grippers with bearing assemblies for guidance and stability, electro magnets, and entrapment compartments. Keep in mind robot accelerations, decelerations, and payload when choosing which way to secure the part to ensure you do not drop the part under worst case scenarios.

Once you have decided on the best way to secure the part firmly, you have to review any fixturing or machinery that the EOAT and part have to interface with. These could put further constraints on part securing mechanisms and framework. The frame should be robust and made to last for millions of cycles. Protective routing of tubing and cables should also be included in the frame as well as mounting locations for controls and valving.
Custom EOAT can allow your robotic cell to be more functional by including value added applications. Once the process is developed, keep in mind that the EOAT can be designed to do more than one function of the process and therefore reduce machinery and fixturing needed.

Richard Petz, General Manager
SAS Automation, LLC - USA
1200 S. Patton St.
Xenia, OH 45385
Tel: 1-937-372-5255
Toll Free: 1-888-SAS-EOAT (1-888-727-3628)
Email: getagrip@sasgripper.com
Web: www.sasgripper.com

About SAS Automation

SAS is a leading supplier of modular EOAT components and robotic gripper systems – capable of servicing any part and any robot. SAS manufactures in the U.S. “get a grip!”, and distributes “nip it!” Nile sprue nipper line, and “GRIP IT!“ Asian chucking/gripper line. SAS is ISO 9001:2000 Quality Certified and specialists in robotic end-of-arm tooling & gripper systems, sprue nippers, CNC degating & Insert Mold tooling for manufacturing, packaging & plastics industries. 

SAS Automation Robotergreifsysteme GmbH - Europe
Im Schlehert 26
D-76187 Karlsruhe, Germany
Tel: +49 (0)721 26306 - 0
Email: info@sas-automation.com
Web: www.sas-automation.com