Cobot End of Arm Tooling (EOAT): Most Common Types and Applications
Investing in collaborative robots requires a reasonable amount of knowledge regarding cobots. Hence Qviro has devised this article for your benefit.
So what is an End of Arm Tool?
It is a peripheral device that is attached to a cobot’s wrist. This would allow a cobot to engage with its designated task and determine which tasks a cobot can and cannot perform.
In this article, you will find the most common types and applications.
While some end of arm tools help cobots perform packaging and palletizing operations, others can be used for machine tending only. Still others can be used for manufacturing processes, quality testing and inspection alone. This means you can’t expect one EOAT to handle all types of tasks.
Which is why we have come up with this article. We have discussed in detail the various types of cobot end of arm tooling (EOAT) you may find on the market. We have also shed light on the applications of each of them to help you select one that’s best suited for your tasks.
Types of End of Arm Tooling
Their name makes crystal clear what ‘grippers’ are all about. Cobots use them for grasping objects and transporting them from point A to point B. Grippers are, therefore, a suitable choice if your processes involve pick and place or assembly operations.
Manufacturers need to pay attention to two factors when choosing grippers. They include the type of material the gripper is made of and the handling application. Here are the most common types of grippers that are available today:
Such grippers come with mechanical fingers that they use to manipulate objects. You can identify them from their design which is similar to that of a crab’s pincers. Most of them also come with stroke and force features, thereby helping the cobot perform tasks with human-like dexterity.
Yet another notable feature of mechanical grippers is that their fingers are replaceable by default. You could thus easily replace them when they wear out due to long-term use or abuse. That’s why you can rely on these grippers to perform heavy-duty tasks.
Vacuum grippers have suction cups that they use to handle workpieces of irregular shapes or uneven surfaces. Some of them also rely on a closed-cell foam rubber layer to do the same. Two types of vacuum grippers are available on the market:
Such grippers are the best choice for tasks that require massive amounts of force. That’s because they draw their strength from pumps that can supply up to 2000 psi. But not everything is great about them.
The oil used in the pumps makes them messier to use. You’d also have to spend more on their maintenance because these grippers get damaged more often due to the amount of force they apply.
While it might sound odd to read, newer vacuum grippers run on electricity. This makes them slightly less powerful than their hydraulic counterparts, but it also makes them more user-friendly.
These grippers operate relatively inexpensively because they do not rely on an external air source. They also produce less dust and noise and have fewer maintenance costs too.
Adhesive grippers provide the best of both worlds. On the one end, they are incredibly lightweight and can thus be used to pick up flexible objects, like fabrics. On the other end, the fact that they don’t rely on a power source decreases their running costs.
Having said that, with their adhesive substance losing its stickiness with each use, the reliability of these grippers follows suit. You’d either have to replace their sticky substance altogether or give it a fresh coat after every few weeks or months, depending on usage.
Magnetized grippers: their fingers are made of a ferrous material and exploit the magnetism principle to hold ferrous workpieces.
Dual grippers: these models have two gripping devices fitted in one. This allows the same gripper to perform the functions of machine loading and unloading.
Sensory feedback grippers: such models have a sensor located in the fingers which relay the correct grip force needed to handle fragile objects.
Sensors help cobots perform tasks grippers won’t. By attaching a sensor to the cobot, you’re basically enabling it to perform delicate operations and handle fragile objects. These are the kind of tasks that require the finesse and soft touch of a human hand, which is something grippers can’t offer.
Force sensors: such sensors give highly accurate force measurements, thereby giving you maximum control over the movement of your cobot. This enables you to automate the most complicated processes.
Collision sensors: these sensors are equipped with a built-in safety feature that helps shut down the cobot when the sensor collides with an obstruction. You can thus count on them to ensure the safety of your workers and the cobot itself.
Tools and Tool Changers
While the number of tools currently being used as EOAT is endless, some are more commonly used than others. They include deburring tools, paint guns, shears, welding torches, drills, arc welding torches, spot welding tools and more.
Tool changers, as their name implies, help expedite the automation process by making the tool changing process quick and effortless. All a robot operator has to do with them is to apply a few clicks, and they can switch the welding torch with a paint gun.
Pro Tip: regardless of the type of CEOT you invest in, make sure it comes with a built-in tool changer. This decision will help increase the speed of your automation process.
Applications of Cobot End of Arm Tooling
Pick and place operations
EOAT enables the cobot to pick and place different types of parts simultaneously. Take the example of magnetic EOAT. It allows the pick-up and placement of steel, iron, and other ferromagnetic objects while leaving the non-ferrous ones in their place.
Many companies are already using welding EOAT for spot-welding and arc welding processes. This has enabled them to produce high-quality welds in a fraction of a time it took them previously, and that too without endangering their workforce as cobots can work with minimal oversight.
Loading and unloading objects
A Denmark-based gear manufacturing company put together a cobot and an RG2 collaborative gripper to load and unload the CNC machines at its warehouse. It didn’t stop at that. It then replaced the gripper – which had a single grip – with one that had two grips and was able to decrease its cycle time further.
This category of EOAT involves tapping and drilling threads and machine holes into materials to trim, grind, debur and cut the material to get the desired shape, size and smoothness. Application of these forms of EOAT can be found in the assembly lines of automotive industries.
Handling delicate objects
Vacuum EOAT let you adjust its air pressure – which creates vacuum grips – to fine-tune their force level as per the fragility of the product being handled and deal with the product with a soft touch. Other EOAT, especially those with a soft grip, can handle food items without causing damage.
One glass manufacturer in France automated their glass polishing process by supplementing a cobot with a sensor and gripper. Apart from reducing worker strain, this decision helped increase capacity. Their workforce is happy, too, as they are free from performing tedious and repetitive task.
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