Grinding Robots: Automating for Productivity and Safety
Modern manufacturers understand that automated grinding is part of an efficient finishing process. Today’s leading companies deploy robots for these tasks due to the immense benefits that robots provide. Unfortunately, you often have little control over imperfections in your parts. However, you do have control over optimizing your finishing process. This article covers why manufacturers choose to integrate, the available options, and how to integrate your first grinding robot.
When are Grinding Robots Useful?
Manufactured parts are often produced with burrs and other imperfections. These undesirable features are part of the normal manufacturing process. Defects are especially prevalent in machining and casting facilities. Manufacturers in these industries know that you can’t ship parts in this condition. Unfinished parts can be dangerous and unusable in such a condition.
In the past, manual grinding was the best option. It wasn’t uncommon to walk past a section of a dozen technicians grinding away at parts. The tooling required is heavy and dangerous. Furthermore, the PPE required is sometimes more akin to a spacesuit (see above image). This depicts the personal hazards of grinding tasks, especially when seen in person. Grinding accidents include:
- Dust and fume inhalation
- Fire and explosive hazards
- Eye and skin contact with sharp particulates
- Hand-arm vibration syndrome (HAVS)
Grinding applications tend to be mundane for technicians. There isn’t much fulfillment or critical thinking involved with grinding tasks. Workers' performance inevitably suffers over time. Fatigue also becomes a factor since grinding involves considerable effort and strength. Ultimately, these factors lead to reduced productivity and part quality in the long run. Manufacturers experience less throughput than theoretically possible and errors and defects on parts.
How Robots Help
Robots automate this mundane and dangerous task. Robots can handle grinding tasks at a highly productive rate thanks to their increased strength and speed. Robots don’t mind boring or repetitive tasks. Additionally, they won’t suffer from physical or mental fatigue. Automating their grinding applications allows manufacturers to retrain and redeploy their technicians. Other sections of the facility include more complex tasks. High-performing companies know which tasks are difficult or impossible to automate. They consistently allocate their employees accordingly.
Additionally, integrating a grinding robot removes people from one of the most dangerous tasks in the building. Maintaining a safe working environment is crucial for morale, avoiding fines and litigation, and keeping the doors open. Because of these reasons, hazardous tasks are often the first targets for automation.
Types of Grinding Robots
The range of grinding tasks allows for flexibility in selecting your robot. Consequently, the grinding application features a diverse lineup of robot types. There is a grinding robot for your needs, from the most simple to highly complex.
Industrial Six-Axis Robots
The six-axis robots are the jack-of-all-trades in the industrial robot family, so it’s no surprise to find them here. Their dynamic range of motion allows them to handle the most complex grinding tasks. Six-axis robots can reach over, around, and contort themselves to the application's requirements. For example, aerospace and automotive manufacturing often produces large parts with complex geometries. In many cases, six-axis types are the only robots capable of meeting these demands.
Collaborative Six-Axis Robots
Manufacturers considering six-axis robots have a few options available. As one of the more expensive robot types, it’s important to research the available offerings. Industrial robots increase in cost as reach and payload capacity increase. However, there are collaborative robots available for specific applications. These robots are often less expensive and are a better option when working around people is inevitable.
However, it’s essential to understand that these robots are often smaller than industrial models. As a result, collaborative robots will have a limited reach and payload capacity. Therefore, they won’t boast the same range of performance as their industrial counterparts in this regard. They are a great choice for grinding applications in metal industries producing small-to-medium sized parts. Cobots will excel more when those parts are more complex.
The SCARA robot is best deployed for straightforward grinding applications. SCARAs feature great speed due to their mechanical construction. However, their design comes with some notable drawbacks. They can’t compete with six-axis models in reach or range of motion.
For this reason, SCARAs are best suited for small and simple grinding tasks. These are common for small metal shops and general metal manufacturers. However, SCARAs are one of the most affordable robot types thanks to their simplicity. For the proper application, SCARAs can have an outsized impact on your finishing process.
Cylindrical robots operate in many of the same applications as SCARAs. However, they tend to perform better when the product is oriented vertically. Cylindrical robots offer slightly better dexterity than SCARAs. However, they will still be quite limited compared to six-axis robots. Cylindrical robots are another low-cost option in this lineup. Again, however, they will still be limited to the most simple applications. You can find cylindrical robots in automotive and aerospace industrial grinding applications.
How to Integrate a Grinding Robot
Integrating a grinding robot is no small feat. The available options and the considerations required can be daunting. These challenges lead to a difficult integration process if you aren’t prepared. Let’s cover those concepts so you can confidently complete your first grinding robot integration.
End of Arm Tooling
The part of the robot that manipulates or engages with the workpiece is called the “end of arm tooling.” This component is crucial for every application. However, getting it right for grinding applications is even more critical. Particular materials call for certain grinding surfaces. Simply settling for any available grinding tool can be a critical mistake. Alternatively, some grinding tasks might require using a gripper instead. This option calls for an external grinding wheel to finish the part. Be sure to select the right tool for the job.
It’s not just the grinding surface that matters; the size and weight do too. As the grinding wheel spins or vibrates, it generates forces on the robot arm. These dynamics must be accounted for during the robot selection process. Overlooking this can result in a robot that consistently faults out during operation.
The application requirements will strongly determine which robot you choose. Simple applications allow the most freedom in choosing your robot. However, larger or more complex tasks should narrow your focus on more capable options. For example, large grinding jobs will likely limit you to only six-axis robots. On the other hand, grinding a simple casting might allow you to get away with a SCARA robot. Therefore, always let the application dictate the type of robot you choose.
A Note on Programming
Programming a grinding robot tends to be more complex than other applications. This difficulty is because there are more variables to consider. Grinding robots must follow a specific toolpath. This, on its own, can be difficult. However, the robot must also exert a precise amount of pressure on the part. Too much pressure and the part or tool will be damaged. Consequently, if it doesn’t apply enough pressure, the robot won’t be able to smooth the imperfections away.
Additionally, further quality control may be necessary for grinding applications with strict tolerances. Automated quality control requires an external measuring device. Vision and laser systems achieve this optically. For example, after a grinding job, these systems inspect the part. If remaining defects exist, these systems pass that information along to the robot to fix.
Tactile measurement is also possible. The robot, or a secondary machine, can trace the edges of the finished part to look for imperfections. Once found, the robot can reapply its tooling to the part to complete the task.
While explained simply here, you shouldn’t underestimate these considerations. Grinding robots can positively impact your facility’s throughput and efficiency. Additionally, they can keep your employees safe from the hazards associated with this task. However, grinding applications can be complex. As long as you’re prepared and conduct proper research, you should find success on your grinding automation journey.
You may be ready to take the next step toward automating your grinding process, but where do you start?
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