November 2018 Issue
Toc

As automation becomes more ingrained in every facet of manufacturing, labor-intensive, repetitive facet of manufacturing, labor-intensive, repetitive tasks are starting to disappear from the operators’ job requirements. Traditionally, finishing operations such as deburring, grinding and polishing have been done manually using a handheld tool such as a die grinder or angle grinder to remove unwanted material from the part.

Suhner’s robotic sander/grinder and orbital sander.

But finishing operations are a good example of a labor-intensive task that is becoming more automated with the help of robotics.

Although effective, manual finishing operations leave a lot to be desired when it comes to safety, health and consistency. Finishing tasks are a manufacturing challenge, often performed by operators in dusty environments while in uncomfortable positions and using loud, vibrating tools. The tedious work can also leave operators prone to errors and defects, leading to inconsistent quality.

Advancements in robotics are leading manufacturers to re-evaluate their finishing operations to reduce their reliance on manual tools.

Finishing Factors

Quality, consistency and safety are all factors automated finishing can address. The precise nature of robots reduces the likelihood of defects that can occur during manual finishing operations, reducing scrap rates.

Suhner’s robot tools can be mounted directly on the robot arm, such as this air file/saw.

Additionally, having robots perform these tasks frees up operators for more productive work. They can spend more time applying their skills to programming, loading the robot and quality inspections.

While limitations have stopped automated finishing from being implemented in most shops, advancements in robotics to perform these operations are leading manufacturers to re-evaluate their finishing operations to reduce their reliance on manual tools.

For those manufacturers ready to consider automated finishing, Suhner Industrial Products Corp. now offers robot solutions for automated finishing operations.

Suhner has offered manual polishing, grinding, cutting and deburring tools for 70 years. Recently, the company took these tools to its machining division to create end-of-arm tooling for manufacturers doing repetitive high-volume production to improve their finishing operations anywhere a handheld tool is typically used.

The reason it has taken so long for automated finishing to become more widely adopted is it difficult to perform with the required accuracy. The complexity of the part and the robot’s limitation to generate a path equivalent to the part edge make it difficult. Also, more complex parts and parts with higher surface finish requirements may require significant programming time and accessories to achieve acceptable robot paths and surface finishes.

But now, “the accuracy of the position of the robot has improved greatly,” says Lee Coleman, director of sales and marketing, machining division at Suhner. “Also, with regard to payload capacity, robots have arrived at the point where you can take advantage of a variety of end-of-arm tooling.”

Robotic Sense

So how do robots mimic the methodology of manual finishing operations? Operators can use sight and touch to identify high or low spots and they can feel how hard they’re pressing on a part. These are things robots can’t inherently do.

Suhner’s 50-mm-wide belt sander for robotic applications is available with and without automatic belt change.

Therefore, to ensure constant surface pressure on the part, a touch force sensing and feedback device is used to optimize the finish on the part and increase efficiency of the finishing tools. This allows finishing operations that were previously not suitable for automation to now be automated.

“The main factor for robots to perform finishing is the feedback between the surface and the sensor in the robot,” Coleman says. “Force sensors go from the end-of-arm tooling to the robot. And based on the sensor, it will relay to the robot when there’s too much force or too little force.”

However, some solutions will not require touch force. If the arm just needs to move across the part with a grinding wheel or deburring tool or for a cut-off application where the tolerances are not that important, those types of applications don’t necessarily need touch force sensing.

“As word starts to spread in the industry about what you can do with automated finishing, I believe it will be used more and more.”
Lee Coleman, director of sales and marketing, machining division, Suhner Industrial Products Corp.

“But to accurately grind or polish a part, you absolutely have to know the position, the feedback and the pressure,” Coleman says. “It just depends on what the customer is trying to do.”

Suhner’s robot solutions for automated finishing are available for deburring, grinding, brushing, polishing, filing, belt sanding or tool spindles and are easily integrated. Applications for the new tools range from automotive manufacturing and deburring operations to stainless steel machining, drilling and tapping – essentially all areas of manufacturing.

An orbital sander is used in this robotic polishing of a stainless steel sink.

The tools can be mounted directly on the robot arm, ready for continuous use. Additionally, they are compatible with all robot manufacturers, making them versatile for demanding, high-performance applications.

Implementing automated finishing operations can seem daunting, particularly for smaller shops that lack existing automation. Fortunately, however, suppliers such as Suhner can help manufacturers overcome implementation challenges by offering expertise throughout the process.

“Also, where available, we can get our abrasives team involved to help the customer select the best abrasive product needed for the specific application,” Coleman says.

As for the question of the manufacturing industry moving more toward automated finishing, Coleman says the answer is twofold.

“First, for those only making say 10, 20 or 100 parts, hand grinding and polishing will never go away,” he says. “And even for dies and molds with those fine surface finishes, that can never be replaced with a robot.

“But for repetitive applications that do the same thing over and over,” he continues, “automated finishing is absolutely the answer. It is already being used in the automotive industry, which is always at the forefront of technology. As word starts to spread in the industry about what you can do with automated finishing, I believe it will be used more and more.

“We’re definitely in the infancy stage and not the maturity stage.”