What's a mechanical gripper?

A mechanical gripper is an end-of-arm tool used by industrial robots to grasp and manipulate objects. 

Mechanical grippers use mechanical means like gears, cams, screws, or toggles to open and close metal jaws or “fingers” around an object.

• They can grab on like nobody’s business, using high gripping force generated from electric motors, pneumatics, or hydraulics. This allows them to handle heavy payloads up to several hundred kilograms.
• Mechanical grippers are very rigid and precise, which makes them able to repeatedly position objects accurately. As a result, this makes them well-suited for precise automated tasks like machine tending, material handling, and assembly.
• They come in different designs like parallel jaw, angular jaw, and multiple finger grippers. The number of jaws or fingers, size, stroke distance, and other specifications can be customized for the application of choice. 
• Integrated sensors provide useful feedback on grip force, slip detection, and object present status. This helps make sure you get reliable gripping and prevents damage to objects.
• Options like quick-change adapters, interchangeable fingers, and integrated tool changers allow easy and rapid switching of grippers and tools.

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What are the benefits of these end-effectors? 

Let’s take a look: 

• All-around increased productivity: Mechanical grippers allow for continuous operation with pretty much zero fatigue, leading to higher output and efficiency.
• They slash labor costs.  Automating repetitive tasks with mechanical grippers can lead to significant savings in labor costs and zap the risk of human error.
• So much safer. By handling hazardous or heavy materials, mechanical grippers minimize the risk of injuries, creating a safer work environment.
• Quality goes through the roof. The precision and consistency of mechanical grippers ensure high-quality results in production processes.

Real-world applications of mechanical grippers

There are many industries where mechanical grippers are common in day-to-day operations.

They are: 

• Manufacturing: In automotive and electronics manufacturing, mechanical grippers are absolutely necessary for assembling parts with precision and speed.
• Pharmaceuticals: In the pharmaceutical industry, the accuracy of mechanical grippers guarantees the safe handling of delicate and sensitive materials, which maintains the integrity of drugs and other products. 
• Food and drink: In the food industry, mechanical grippers can be used for packaging and sorting, and handling a variety of products while maintaining high hygiene standards.
• Logistics and warehousing: Mechanical grippers enormously streamline the process of sorting, packing, and palletizing goods.
• Recycling and waste management: These grippers are also employed in recycling operations to sort and handle materials, which is especially beneficial in efforts toward greater sustainability. 

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Things to look out for when you're choosing a mechanical gripper

Don’t break out your credit card just yet!  When you’re shopping for the right mechanical gripper for your robot, there are a few key factors to keep in mind.

They are: 

• Grip force - This refers to how much closing force the gripper can apply to really grasp and hold objects. You'll want adequate grip force for the items you need to handle, but too much can end up breaking fragile objects. Try to look for models with adjustable force control.
• Stroke per finger - The stroke indicates how wide the gripper can open to accommodate different-sized objects. Basically, more stroke allows picking up larger items, so make sure the stroke range suits your application.
• Number of jaws - Two or three jaw grippers are very common; three jaws provide better stability for irregular shapes, while two jaws work well for many objects – and are simpler.
• Actuation method - Pneumatic, electric, and servo-electric grippers each have pros and cons. Keep in mind the speed, precision, and integration with your robot control system.
• Weight capacity - Choose a gripper rated to safely handle the maximum expected item weight with a safety margin. An under-rated gripper can run the risk of mechanical failures.
• Easy integration - Look for plug-and-play grippers that can easily integrate with your robot using tool changers or standard connections. This ease of integration saves development time – and headaches. 

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Our picks for the 5 best mechanical grippers for Industrial robots

There are a ton of great mechanical gripper options on the market. But that doesn’t mean that there aren’t a few standouts that definitely need to be on your radar. 

We’ve narrowed things down to the top 5 options for you to consider: 

SCHUNK EGP 40:

The Schunk EGP 40 has a compact size, high-precision parallel jaws (40N force), and integrated air/electric cabling.

Price: starting at ~ $2,600.

Zimmer LPR-Lite:

This standout mechanical gripper has a simple pneumatic design, lightweight (0.5 kg), 3 kg payload, and two-finger parallel jaws.

Price: starting at ~ $2,100. 

Festo DYN Grip2:

Flexible finger positioning, built-in force sensors, 40 kg payload, handles rigid/delicate objects.

Price: starting at ~ $11,400. 

Piab COAX Suction Cup Gripper:

The COAX series features a wide payload range (3 to 50+ kg), adaptable gripping pads, an integrated ejector, and modular design for various objects.

Price: starting at ~ $2,800. 

SMC CG Series:

Pneumatic gripper with compact design and different finger lengths for diverse applications.High gripping force (up to 226 N) suitable for handling heavier objects. Double-acting design allows for both internal and external gripping. Plus, it has a durable construction with an anodized aluminum body for long-lasting performance.

Cost-effective option starting around ~ $1,200.

How to connect your mechanical gripper to a robot arm

Connecting a mechanical gripper to your robot arm is an all-important step when you finally want to get it up and running. 

Here are some tips:

• Check for compatibility first! Make sure the gripper is designed to interface with your specific robot model. Many grippers are made to connect to common robot arm connectors like ISO 9409-1-50-4-M6, ISO 9409-1-31.5-4-M5, or ISO 9409-1-40-4-M6, so make a note of this first!
• Look at the datasheet for your robot arm to find the type of connector it uses. This is often located at the end of the wrist - it may be an M4, M8, or a custom connector.
• Get the right adapter. If needed, obtain an adapter plate, flange or coupler to connect the gripper to the robot arm connector. Most adapters are often available from the robot and gripper manufacturers.
• Run some internal wiring. Route any necessary air lines or electrical wires from the gripper internally through the arm – make sure to secure them so they won't snag.
• Set payload limits. Add the gripper's weight to the payload you plan to lift and ensure you are within the robot arm's rated payload capacity.
• Establish communication. Configure your robot controller or external I/O to send control signals to open and close the gripper jaws.
• Fit test. Do a dry run attaching the gripper to validate fit and function before applying power.

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FAQs

Is a mechanical gripper better than a vacuum gripper?

It depends on your application. Mechanical grippers are great for rigid objects that can take a compressive gripping force. Vacuum grippers work well for picking up flat, smooth surfaces or delicate items that might be damaged by mechanical jaws. Keep in mind the size, shape, weight, and surface of the objects you need to handle.

How do I provide power to my mechanical gripper?

Most electric grippers run on 24V DC power, so you'll need a 24V DC power supply. But do make sure that it can provide enough current for the gripper's operation. The gripper may have screw terminals, M8 or M12 connectors to wire it up. Check the specs!

What communication interfaces are available?

Grippers can use digital I/O, analog I/O, RS485, Ethernet/IP, Modbus TCP, CANopen, EtherCAT, or other industrial communication protocols. Choose a gripper that's compatible with your robot controller. Using the robot OEM's first-party gripper integration is easiest.

How do I control grip force to avoid damaging objects?

Many grippers have force control, where you can adjust the pressure applied. Start with a lower force and test. Integrated force sensors let you monitor real-time forces during grasping and releasing. You can also control speed for gentler handling.

How often does a mechanical gripper need maintenance?

Basic inspection and lubrication every 6 months can keep a gripper running smoothly. Replace worn gripper tips/fingers as needed. Higher duty cycles may require more frequent maintenance. Follow the manufacturer’s recommendations.

How are mechanical grippers rated for payload capacity?

Gripper payload capacity refers to the maximum weight it can safely handle. This rating typically accounts for several factors, including:

• Jaw design and materials: Stronger materials like steel can handle heavier loads compared to aluminum.
• Air pressure (for vacuum grippers): Higher pressures allow for a much greater gripping force and heavier payloads.
• Motor power (electric grippers): More powerful motors provide more force for gripping heavier objects.
• Duty cycle: Continuous use at high capacity may require a higher-rated gripper than occasional handling of lighter objects.

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Summing up

We know that choosing the right gripper for your application can make your head spin at first. There’s so much to choose from, and every company claims they’ve got the best thing since sliced bread. 

But now, with your choice of the top 5 mechanical grippers, you’ll be able to easily take your Industrial robot to a new level of scalability and productivity! 

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Next steps

If you're on the lookout for the optimal robot arm and end-effector tailored to your needs, look no further than RO1 from Standard Bots. Specially designed for versatility,  RO1 readily accommodates a broad array of mechanical grippers, making it suitable for diverse applications in both large and small machine shops. Key features include:

• Affordability: RO1 stands out as a remarkably cost-effective solution in its class, offering significant savings compared to other established brands, and coming in at about half the cost of its nearest competitors.
• Advanced Vision Systems: Equipped with state-of-the-art vision technology, RO1 simplifies complex tasks through its user-friendly, no-code programming interface, adept at pinpointing even the smallest imperfections.
• Collaborative and Safe: Designed with integrated safety sensors and collision detection, RO1 ensures a secure and cooperative working environment on your shop floor.

Chat with our knowledgeable solutions team for a free, 30-day onsite trial. Receive comprehensive insights and all the necessary guidance to successfully integrate your first robot into your operations.