The Business Benefits of Machine Tending With Collaborative Robots

Machine tending – loading and unloading manufacturing machinery – is one of the core applications for industrial robots.  From 1961, when the first industrial robot from Unimation was installed in a GM die casting plant to today, machine tending remains a common application for robots.  The fundamentals are simple: Remove a finished part from a machine, load an unfinished blank into the machine, and repeat.  The process remains the same, but the scope and benefits have certainly evolved over time.

What types of machines can be automated with robots?  It’s a long list, including CNC machine tools, injection molding machines, die casters, assembly systems, additive manufacturing machines, and more.  In some cases, removal of the finished part is the only automated process.  In other applications, blanks or component parts are loaded as well.

The labor crisis in manufacturing continues to be a key driver for machine tending automation around the world.  In April 2023, the Bureau of Labor Statistics reported 694,000 job openings in the US manufacturing sector alone.  While that is down from the peak of 1,000,000 open manufacturing jobs in January 2021, it is still higher than pre-pandemic levels and shows no significant signs of improvement.  Machine tending is considered one of the DDD jobs (Dull, Dirty and Dangerous) that are difficult to fill and have high turnover.

The Traditional Approach

With no immediate solution to the manufacturing labor shortfall in sight, the challenge facing companies large and small is to boost productivity and output with the existing manufacturing team.  And that’s where robotic automation comes in.  While machine tending has been a popular application for decades, the traditional (non-collaborative) robot approach has some limitations that make it impractical in many operations:

• Floor space – safety guarding required by traditional automation consumes large amounts of manufacturing floor space, and may require the re-location of machines, high voltage power lines and other utilities.
• Complexity – traditional robots are difficult to program, operate and maintain.  Small shops just don’t have the skilled resources to dedicate to traditional automation, and large shops don’t want the expense.
• Lead times – traditional automation lead times are typically 3-5 months, an eternity for any company fighting labor challenges day to day.
• Limited flexibility – traditional robots are difficult to move to a new location, and to re-program for new parts, limiting the overall efficiency.
• Total cost – given all the above points, machine tending with traditional robots is an expensive investment that is difficult to justify.

Enter the Cobot

Which brings us to collaborative robot (cobot) machine tending.  Universal Robots introduced the first cobot in 2008 and has shipped over 75,000 collaborative robots to date.  Machine tending was the first application for UR cobots and remains our biggest application segment.  Cobot machine tending has significant advantages over traditional robot automation:

• Floor space is not an issue.  With a proper risk assessment, machine tending cobots can be deployed throughout manual lines with no safety fences, interlocks or barriers.  Most installations do not require any relocation of machines, power and other utilities.

• UR based cobot machine solutions can be programmed and operated by manufacturing engineers, technicians, and line operators, not robot engineers.

• Long lead times are in the past.  UR cobot solutions can be in production in weeks, not months.  PO to Production in 3 or 4 weeks is common.

• Simple programming delivers maximum flexibility.  New parts can be programmed in minutes, maximizing flexibility in the world of high-mix, low-volume production.

• Total cost is typically 1/3 to ½ that of traditional automation.  And with short lead times, UR cobot solutions deliver ROI in record time.

Productivity

Boosting productivity with cobot automation takes multiple forms, but centers on leveraging the company’s skilled manufacturing operators and technicians.  The basic configuration involves a 1:1 ratio of cobot to machine.  However, depending on takt times and the layout of the machines, a single cobot can support 2 or even 3 machines, with a single operator to keep the cells supplied with parts.

In many companies, the labor shortage has idled machines as there are no operators to load / unload parts.  This is a painful scenario, as the lost production volume impacts top line revenue, while the idle machine continues to depreciate, takes up floor space and in the worst case consumes cash flow with interest expenses.  Lost productivity also threatens customer relationships with delayed shipments and reduced volumes.

It's also important to remember that even in companies with no labor issues, cobot automation will improve productivity.  Manual machine tending means production stops during breaks, lunch, and promptly at the end of shift.  Continued operation for two 15-minute breaks and a 30-minute lunch break per day will increase production by 12.5% over an 8-hour shift.  In addition, flexible part presenters, machine process monitoring, and tool wear compensation can be utilized to further increase production at the close of normal business hours, often running an unattended second shift.

Consistency

In manual machine loading operations, the cycle time is gated by the pace of the operator.  Maintaining the shortest cycle time and highest production rate over an 8-hour shift is incredibly difficult, if not impossible.  Cobot machine tending solutions deliver the highest production output, as the cycle time is now under the control of the cobot and machine process.

In a similar fashion, operators are challenged to load blank parts consistently throughout an 8-hour shift.  Parts that are only slightly mis-aligned or improperly seated generate scrap that directly impacts the bottom line.  Cobot automation is precise and repeatable cycle after cycle, and built-in force sensing on the UR cobots can further ensure blanks are aligned and properly seated.

One of the major challenges to robotic machine tending with traditional robots is robot/machine utilization.  Because traditional automation is essentially permanently installed, the company must be assured of sufficient volumes of parts to keep the robot/machine fully utilized.  The flexible nature of collaborative robot machine tending allows the cobot to be moved from machine to machine, depending on the production plan for the day or week.  In many cases cobots are mounted on a cart that can be wheeled up to the assigned machine.  This keeps the robot utilization extremely high, speeding up the ROI.

More on Labor

Part of the labor challenge in machine tending is not just hiring – it is also critical to increase job satisfaction for current employees.  That’s difficult when the job is standing all day in front of a machine, loading and unloading parts while trying to maintain a consistently short cycle time and no scrap from mis-loads.  Automating the Dull Dirty and Dangerous increases safety, reduces insurance compensation claims and increases employee job satisfaction.  When prospective employees recognize they can work with robots, not like robots, the hiring process is far easier.

Low risk, rapid deployment cobot machine tending solutions from Universal Robots and our partners – to get started, download our Guide to Machine Tending.