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Get a Grip! Choosing the Right Robotic Gripper

 


If you need robot tooling to pick up, manipulate, and place your product/part, chances are you're going to use a robotic gripper.

Arguably the most common type of end-of-arm tooling (EOAT), robotic grippers are found in virtually every industry and context from food production and cleanroom environments to foundries and distribution centers. These grippers come in a variety of types, sizes, and configurations -- friction, encompassing, hydraulic, pneumatic, electric, magnetic, etc. 

Friction vs. Encompassing

There are two main types of grippers – friction and encompassing – which are broken down by the way they pick up materials. Friction robotic grippers hold the part through force alone, while encompassing grippers surround the part. Which one is right for you? It all depends on the material. Generally speaking, friction grippers are better suited for harder materials, and encompassing grippes are well suited for flexible or softer materials, like bags or boxes.

Angular or Parallel?

Many grippers come with two or three jaws – except for vacuum grippers which often come with rows of suction cups for gripping. Parallel grippers, the grippers with two jaws, close onto either side of a product and lift it up. An angular robotic gripper moves more like a human hand, with the “fingers” wrapping around the product. In a majority of cases, companies will choose the parallel design because it is easier to design for and more practical than the angular option.

Of course, it isn’t just about how many jaws or fingers the robot EOAT has – it is also about the size and shape of them. The length of the jaws can have an impact on cycle speed and effectiveness. Longer jaws many be necessary depending on the work cell and application (example: removing a part from an injection mold machine). In addition, grippers are commonly constructed with two or three fingers (actuators) for grasping an object. Integrators consider the size and construction of the part being manipulated to determine how many actuators are best. 

Use of Force

Once you decide whether your application needs a friction or encompassing gripper, there are several different kinds to choose from, and once again, it is all about the part materials and weight. These grippers are powered in many ways, and the wrong kind of force could damage or ruin your product. Other factors you could consider when choosing your gripper cost and space constraints.

The most popular type of gripper for robotic systems is the pneumatic gripper. These grippers are compact, lightweight, and capable of applying a significant amount of force. These grippers do not have the bulk of motors or gears, which can make a gripper significantly larger, so they are versatile enough to fit into tight work cells. Sometimes, pneumatic grippers are combined with other elements, like suction cups or magnets, to better grip materials.

If you need more force than a pneumatic gripper can provide, it is time to move on to the hydraulic gripper. These grippers can deliver plenty of force, but they can be a mess for your factory because of their oil, pumps, and reservoirs. Another cleaner option is an electric robot gripper, which easier to maintain, while also providing the same amount of force as the hydraulic options.

 These grippers can be larger than pneumatic grippers because they do include motors, but with the help of microprocessors, they are much more adaptable.

Choosing Your Gripper

RobotWorx' integration team works with each customer to determine which robotic grippers is best suited to the application, work cell design, and most importantly, the part/product. Some products, for example, will be damaged if too much force is applied while others can handle significant amounts of force. As mentioned above, a number of factors, such as tooling cost, force necessary, part weight, and acceleration /deceleration rates are considered when selecting a robotic gripper solution. Our staff works daily to ensure that you are completely satisfied with the quality of your parts and systems.

For more information about robotic grippers, call the RobotWorx Sales Department at 740-251-4312 or contact representatives online