We may think that manufacturing happens behind the scenes, but this is the wrong view. From another perspective, manufacturing supply chains and support infrastructure are at the heart of modern life.
Thanks to robotics and automation, manufacturing finds itself at the center of the engineering revolution. Robotics is especially important today given the number of vacant industrial jobs and companies seeking a competitive edge in globalization.
Collaborative robots (cobots) and automated robotic arms can use different types of tools depending on the application and desired outcome. One distinction worth understanding is between pneumatic and electric end-of-arm tools (EOAT). These are tools at the end of the robot's manipulation arm that are used to interact with materials and workpieces.
Why does this matter?
Robotics is not a boring subject - but unless you already work in the robotics, manufacturing or automation industry, it may take some convincing to get you to care about end-of-arm tooling.
Suffice it to say, modern industrial robots can't lift, carry, turn, cut, carve, measure, test, or many other tasks without end-of-arm tooling.
Typical examples of end-of-arm tools include:
- Welders
- Grippers
- Laser cutters
- Measuring tools
- Material removal tools
- Crash and force torque sensors
- Suction cups or electromagnetic lifters
In addition to tools for cutting, grinding, or polishing, robot arms can use EOATs to perform tests, calibrations, or inspections.EOATs give robots the ability to perform the tasks we ask of them, and they support a growing number of robot platforms and applications.
Below, we'll take a closer look at the pros and cons of pneumatic and electric EOATs.
Pneumatic EOAT: advantages and disadvantages
Without the right end-of-arm tooling, an industrial robot can't accomplish the tasks set before it. There are many concerns on the business side as well.
First and foremost is pneumatics. Pneumatic EOAT is the first choice of robotics engineers. But what are the specific advantages? On the one hand, pneumatic EOATs have a high power-to-size ratio compared to other options. As a result, they can be more easily installed into certain robot chassis or industrial work areas. Companies concerned about start-up costs may also be better off using the more familiar pneumatic actuators and EOATs. the equation goes beyond that, but using pneumatic EOATs can make it easier to manage day one costs.
Pneumatic operation is ideal for efficient setups where the shape and size of the workpiece does not change as often. Many pneumatic EOATs can only machine or operate one type of part.
However, pneumatic EOATs are not without their drawbacks. They are the preferred choice now, but they have significant drawbacks that may see them retired from the factory floor in favor of their electric counterparts in the coming years.
These drawbacks are easier to address in some cases, but they are still worth noting as companies consider this option:
- Less advanced programmability: Pneumatic clamps and other end-of-arm pneumatic tools offer simple opening and closing functions compared to the more programmable electric EOAT.
- Limited control over grip: The electric EOAT grip is much more customizable, although pneumatic variants may allow basic grip control by varying the pressure.
- Requires compressed air: EOATs require constant use of compressed air, which increases their ongoing operating costs.
- Possible quality compromise due to lubricants: Contaminants in compressed air systems can pose a threat to some particularly delicate products, such as food, depending on the application.
Electric EOAT: Pros and Cons
The engineering community is increasingly looking to electric end-of-arm tools as a logical alternative to pneumatic mechanical arm tools. While they can provide many of the same functions, electric actuators and EOATs are much more flexible in some key ways.
Here are the advantages of electric end-of-arm tools:
- Better Programmability and Control: The motorized EOAT provides the user with significant and programmable control over positioning, tool force, travel distance and travel speed. These features are essential when material, product or part dimensions change regularly.
- Simple System and Setup: The benefit of using an electric EOAT is the elimination of air compressors and their associated maintenance and replacement cycles. The relative simplicity of electric actuators and EOATs is attractive to organizations with limited engineering staff.
- Easier control at lower pressures: As mentioned earlier, pneumatic tools provide only basic pressure control. At lower pressures, it is difficult to derive useful force from the tool. Electric variants eliminate this disadvantage by providing grip even during delicate operations.
- Less stringent space requirements: Since pneumatic controls are fully open or closed at any given time, they tend to require more space cushioning for safety reasons while using smaller parts.
One of the few drawbacks of motorized EOATs like clamps is that, as discussed, they are typically more expensive than their pneumatic analogues. Pneumatic components may be cheaper on day one, but their operating costs (including compressed air supply) can impact ROI. In contrast, electric EOATs may cost more on day one, but maintenance costs are lower.
This cost-benefit trade-off of motorization is something worth considering for companies looking to invest or reinvest in industrial robots.
Selecting Electric and Pneumatic End-of-Arm Tools
There are other ways that your intended application affects your choice of tool end arm. For example, fewer and fewer pneumatic grippers and air tools are already equipped with clamp detection sensors. Motorized EOATs can be more easily integrated into a company's evolving IoT (Internet of Things) infrastructure for data collection purposes.
Ultimately, electric actuators and tools may prove to be a more scalable option for the leaner, greener future of distributed, high-mix, high-volume and affordable manufacturing equipment.