A Good Look

Look to cobots for better abrasives performance, including weld grinding

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As the labor gap for skilled workers widens, manufacturers are increasingly looking to collaborative robots, or cobots, that work alongside humans on the manufacturing floor to complete a variety of tasks efficiently and safely, including material removal. Various industries benefit from cobots performing material removal tasks, from composite sanding to metal polishing to weld grinding. Cobot efficiency, accuracy and simplicity make them a wise choice for manufacturers seeking to fill vacant jobs, reduce injuries and boost productivity in material removal work.

In the world of metal fabrication, cobots can easily operate orbital sanders that wield grinding consumables or abrasive discs to efficiently remove weld beads or other excess material from manufactured parts or finished products – and they do so more quickly and accurately than humans holding a hand tool.

Cobots are the fastest-growing segment of industrial automation and are expected to comprise 34 percent of all industrial robot sales by 2025, according to the International Federation of Robotics (IFR). A substantial part of this growth can be attributed to the welding industry.

Because of their efficiency, flexibility and affordability, welding and fabricating professionals are adopting cobots more and more to increase the productivity of the weld grinding process – and, interestingly, to extend the lifespan of their tools and consumables.

Kane Robotics’ Grit cobot solution consists of a Universal Robots’ robotic arm and ATI Industrial Automation-compliant angle grinder mounted on a mobile table.

The benefits of integrating cobots into weld grinding operations include:

  • Speed and consistency. Cobots can grind welds at a consistent speed, eliminating variations due to human fatigue or other variables. This uniformity enables faster task completion.
  • Reduced downtime. Unlike human operators who require breaks, cobots can work continuously, reducing the downtime associated with manual grinding.
  • Precision. Cobots can be programmed to follow exact paths and maintain the correct pressure and angle throughout the grinding process, ensuring a uniform finish.

Cobots are tireless grinders and ensure the same quality of work on every pass, eliminating the risk of human error. This boosts productivity by allowing operators to focus on more intricate aspects of the weld grinding process.

The right abrasives

While cobots can dramatically improve material removal, selecting the right abrasives for them to use is crucial to achieving the best results, especially for weld grinding. Most cobots are abrasive-agnostic, meaning they can use any type of abrasive. However, not all abrasive discs are created equal, and choosing the wrong ones could result in inefficient grinding and increased consumable costs.

Kane Robotics’ cobot solution performs material removal with superior precision and consistent speed that translates into significantly less strain on abrasive discs.

When selecting abrasives to use with a cobot, operators should consider:

  • Abrasive type. The abrasive material should match the application. For example, aluminum oxide is appropriate for general grinding, while zirconia alumina is ideal for heavy material removal.
  • Grit size. The grit size determines the aggressiveness of the abrasive. A finer grit is suitable for finishing work, while a coarser grit is better for heavy material removal.
  • Backing material. Backing should be based on the material to be ground. Reinforced fiber backing is often preferred for metals.
  • Disc size. Operators should select the appropriate abrasive disc size for the job at hand. Smaller discs are ideal for intricate work, while larger ones cover more significant surface areas.
  • Longevity. High-quality abrasives may cost more initially but they offer longer lifespans and, ultimately, can result in cost savings. Regardless of quality, cobots tend to extend the life of most abrasives.

Abrasive discs must be inspected and replaced regularly to maintain efficiency. Worn discs can increase grinding time and lower finish quality. Fortunately, cobots help mitigate these risks by extending disc longevity.

Traditional manual grinding can lead to excessive wear and tear on abrasive discs, causing them to wear out quickly. This not only increases consumable costs but also leads to frequent workflow interruptions.

Not surprisingly, cobots that perform material removal with superior precision and consistent speed exact significantly less strain on abrasive discs. Cobots follow programmed paths with exceptional consistency, which minimizes the likelihood of overloading discs. Cobots can also adjust their pressure and speed to optimize grinding, ensuring the discs wear evenly. Thus, discs need to be changed less often, resulting in time and cost savings for welding operations.

With the introduction of the Grit cobot solution, Summit Casing Equipment has realized a 100 percent increase in product output.

These savings can be significant for manufacturers or fabricators in any industry, from aerospace to oil and gas.

Case study results

Kane Robotics was contracted by oil and gas equipment manufacturer Summit Casing Equipment to improve efficiency in its weld grinding process. The company makes centralizers, which are metal parts that center the well casing inside the bore hole of an oil well pipe. Welds must be ground sufficiently to ensure equipment functions properly. But Summit found the weld grinding process to be slow and cumbersome, and the company wanted to free up its skilled workers to perform other, more critical jobs.

Kane configured its Grit cobot solution to grind the centralizer welds according to Summit’s specifications. Consisting of a Universal Robots’ robotic arm and an ATI Industrial Automation-compliant angle grinder mounted on a mobile table, the cobot solution incorporates 3M abrasive discs to grind the welds.

Summit’s operators were already using the 3M discs on their hand tools to grind the welds, and they were satisfied with the disc quality and resulting finish. Though 3M produces two newer models of abrasive discs that reportedly further improve the material removal process, the company wanted to continue to use the solution they were comfortable with – a previous generation of abrasives. Kane engineers agreed.

“We didn’t think it was necessary to ask Summit to change their whole supply chain or purchasing process or deviate from the tools used in sanding operations in other parts of their factory,” explains Alan Hiken, chief operating officer, Kane Robotics. “When introducing cobots, we always try to minimize the impact on the customer by making as few changes to their process as possible. We keep it simple.”

The Grit cobot solution provides longer abrasive disc life. Summit operators can perform the weld grinding process on 126 centralizers before replacing discs, up from 42 discs.

Rather than introduce a new abrasive, Kane simply adapted the Grit-ST cobot to use Summit’s existing 3M discs. Kane happens to be a member of 3M’s Robotics Network.

Kane engineers also configured the Grit’s programming to suit Summit’s needs. An important parameter was to align the performance of the cobot to keep up with the welding cycle. Kane designed the cobot’s weld grinding cadence to match that of Summit’s welding process, which included welding two centralizers at a time at specific intervals. With both operations in sync, the product could move smoothly through each manufacturing phase.

After making adjustments to facilitate the loading and unloading of the centralizers, Kane engineers preprogrammed it and taught Summit operators how to use the reconfigurable, mobile, 110 V-compatible cobot.

The operators saw two immediate improvements: First, productivity doubled. The Grit cobot grinds nearly twice as many centralizers per shift as a human can, doubling output. Second, abrasive lifespan tripled. The Grit solution employs the same 3M abrasive discs the operators used, but the discs last 300 percent longer on the cobot. Because the cobot’s precision and consistent pressure and speed cause less wear and tear, operators can process 126 centralizers, up from 42 before replacing the discs.

With the introduction of the Grit cobot solution, Summit has not only seen a 100 percent increase in product output, but it has also been able to repurpose two operators from weld grinding to other tasks. Additionally, the company expects to save $6,000 to $8,000 on
abrasives per cobot per year by extending the lifespan of each abrasive disc.

The abrasive answer

Regardless of the type of abrasives used – any brand of abrasive will work with the Grit cobot solution – Kane sees improvements in abrasive life across the board among all customers that adopt cobots.

Kane Robotics designed the cobot’s weld grinding cadence to match that of Summit’s welding process, which includes welding two centralizers at a time at specific intervals.

Switching from manual to automated processes improves the life expectancy of any sanding or grinding media a manufacturer uses, according to Hiken. While some customers ask for recommendations on abrasives, Kane typically suggests starting with the abrasive that the customer is currently using.

“We take a customer’s existing process and refine it to work with the cobot,” Hiken says. “Introducing a new abrasive would just be another variable that could add complexity.”

Another Kane customer also saw significant improvement in abrasive life by incorporating the Grit cobot solution. This aerospace manufacturer, however, simultaneously upgraded to higher quality abrasive discs. Whether due to the cobot, the new abrasive or a combination of both, the company saw a 30 to 40 percent improvement in production process time when they implemented the new cobot solution.

Implementing cobots into manufacturing processes, including weld grinding, yields multiple benefits. Improvement in abrasive life is a benefit that is more tangible than something like job satisfaction; companies can readily see their decrease in abrasives expenditure and easily measure the cobot’s ROI.

But as abrasives improve, so will cobots. Some companies will begin to automate entire manufacturing processes associated with material removal, including loading and unloading parts onto the cobot and changing out abrasive discs. Kane, however, believes automating everything can detract from the goal of solving the problem that the cobots were initially brought in to solve – in the case of Summit, to grind welds more quickly and efficiently.

“If you removed people completely [as is the case in industrial automation], you would no longer be focused on material removal; you’d be dealing with handling, loading and other processes that would increase time and complexity, taking you further from solving the real problem of reducing grinding time,” Hiken says. “With cobots, we don’t spend time and effort on something that was not the customer’s problem to begin with.”

Part of the beauty of cobots is that they do not replace humans in manufacturing processes; they simply enhance their work – and their abrasives.

Kane Robotics

Summit Casing Equipment

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