The most common purpose of a gripper (sometimes also referred to as an end effector) is to grasp or enclose parts for transfer, insertion, or assembly in automated manufacturing and processing systems. Additionally, grippers are used in environments that are hazardous for human presence. Several factors are required for selection and design to ensure proper gripping. The following considerations will help you in choosing and sizing the right gripper for your application.

1. Part Shape – If the product or part has two opposing flats, a 2-jaw gripper is normally used. If the part is cylindrical, a 3-jaw gripper could be used. Tooling can be designed to accommodate cylindrical parts with a 2-jaw gripper.
2. Accessibility & Part Consistency – Angular grippers are usually low in cost, but the arcing motion of the jaws may require additional tooling clearance and will grip at varying points as part width varies. A parallel gripper is easier to tool in order to compensate for part size. 
3. Part Weight – Grip force must be adequate to safely transport the part. 
4. Orientation & Dimensions – Part orientation and distance from the gripper face affects the gripper selection. 
5. Size – Nominal gripping dimension indicates approximate gripper size. 
6. Variation – Variation in gripping location or encapsulation determines minimum gripper jaw travel. 
7. Air Pressure – The air pressure at the gripper affects gripper sizing and must be taken into account. 
8. Grip On Open or Close – Grip force varies in each direction due to the effective area of the piston rod on some gripper types. Verify that the gripping direction is taken into account when sizing. 
9. Velocity – Higher speeds and acceleration/deceleration affects gripper selection. 
10. Tooling Length – Longer tooling inducts bending moments into the gripper and affects sizing. 
11. Tooling Configuration – If the part is encapsulated, the required gripping force can be lower than if it is grasped on flats only.
12. Product Retention – If part retention upon air loss is desired, springs or locking cams can be specified for the gripper. 
13. Environment – For harsh environments, special platings or materials should be specified. 
14. Synchronous Operation – Most grippers provide synchronized jaw movement. In special circumstances, independent jaw travel is desired and can be supplied by request. 
15. Switching Options – Most grippers offer several switching options. 

See all of PHD’s gripping solutions here.