Category : Market News

Robots help fill gaps in Minnesota’s workforce

Outside Cosmos Enterprises, the big “now hiring” sign is pretty much a permanent fixture.

Robert Grove, who owns the small machine shop, is constantly looking for skilled people to build parts for other manufacturing companies. But he said skilled machine operators are “almost impossible” to find in Elbow Lake, population about 1,200.

Grove, who has 23 employees, trains most of the workers he hires because it’s hard to find skilled workers who will move to a small town.

“Not only is there a lack of skilled workers, there’s just a lack of workers,” he said. “We got to start adapting and figure out what to do.”

A few months ago, Grove found a solution. He invested nearly $250,000 in a robot that can handle many of the repetitive tasks in his shop.

He isn’t the first to do so. A growing number of manufacturers in Minnesota are turning to robots to help ease a labor shortage.

Robots aren’t new in large manufacturing plants, but small companies across Minnesota also are embracing a new generation of robots to stay competitive.

In Grove’s brightly lit shop, the robot sits in a cage to keep workers from walking into the rapidly moving arm. The robot’s job is to load metal blocks into computerized machine tools that shape the parts. It then removes the finished part — all without ever eating lunch or taking a bathroom break.

“For sure you gain 45 minutes a day of production,” Grove said. “That’s real money.”

Grove said the robot doubled the output of two milling machines. It also allows his skilled workers to focus on using their skills, instead of simply loading parts into a machine all day.

Although there was a steep learning curve for workers who need to work with the robot, Grove is convinced his company won’t survive without embracing automation.

“It’s going to get worse as far as I’m concerned, just with the baby boomers retiring,” he said. “I mean, there’s a ton of skilled people retiring every day.”

Grove already is thinking about adding a second robot.

Thirty minutes away, Alexandria Industries has more than a decade of experience with robots. The company, which makes aluminum parts for everything from medical equipment to military rifles, is a much bigger business, employing about 370 workers.

“We have nine robots tending machines today,” engineer Todd Carlson said recently. “I’ve got two more robots on order right now and scheduled to order two more before the end of the year.”

Carlson said robots have a checkered history at the company. In 2001, the company purchased its first, Rosie, to make parts for the telecommunications industry. After the dot-com bubble burst, the contract disappeared and the nearly $500,000 investment sat unused.

“For four or five years we were pretty disappointed with robotics,” Carlson said.

But robots have changed. New versions are easier to program and more adaptable to different jobs.

Carlson said robots have not replaced workers and no one lost their job. But the company has been able to expand despite a perpetual labor shortage.

“It’s a tough labor market out there and automation is really helping us through that,” he said.

Having robots do repetitive tasks, Carlson said, makes for happier workers.

“They don’t like loading parts. They like troubleshooting, they like problem solving,” he said. “So it really changes the level of operator we’re able to attract and it really gives them more satisfaction in the job that they’re doing.”

A workday full of repetitive tasks could explain why many Minnesota manufacturing companies have a hard time finding workers.

A survey conducted last year by the business-consulting firm Enterprise Minnesota found 67 percent of companies reported difficulty in filling open positions.

Bob Kill, president and CEO of Enterprise Minnesota, sees more small companies — especially in rural communities — asking questions about automation.

“I think the challenge is it’s a dwindling workforce,” Kill said. “The market is forcing companies of all sizes to automate where they can and we’re going to continue to see automation of all kinds of types continue to grow.”

About 45 percent of manufacturing in Minnesota happens outside the Twin Cities metro area, Kill said, and many of those companies have no choice but to focus on efficiency.

Mark Sagedahl, who teaches robotics at Alexandria Technical and Community College, advises companies to use robots.

“Ten years ago, 15 years ago, the big trend was outsource because we could do it cheaper, faster overseas somewhere else because of the labor costs, and the big thing was the labor costs,” Sagedahl said. “The problem, the issue, that manufacturing saw was that the quality isn’t there.”

So some of the work that might have occurred shipped overseas is returning to U.S. companies.

Sagedahl, who also helps design robot training programs for companies, said 10 years ago it took computer programming skills to run a robot. But these days, he said, anyone who can use a smartphone can learn to operate the new generation of smarter robots.

The expanding use of robots, he said, might convince more young workers to consider manufacturing jobs.

“Now, what they’ve really gone to is the idea of that robot is almost an extension of a person,” Sagedahl said. “It has multiple skillsets. It has multiple abilities depending on the needs.”

FabTech 2015

North America’s largest metal forming,  fabricating, welding and finishing event heads to McCormick Place in Chicago, IL USA. The upcoming event is expected to cover more than 550,000 net square feet and anticipates over 40,000 attendees and 1,500 exhibiting companies. FABTECH provides a convenient ‘one stop shop’ venue where you can meet with world-class suppliers, see the latest industry products and developments, and find the tools to  improve productivity, increase profits and discover new solutions to all of your metal forming, fabricating, welding and finishing needs.

 

Automation on the Upswing

Manufacturers are implementing more automation than ever before. In fact, robot sales were at an all-time high in 2014. As the skills gap continues to grow the question for many manufacturers is no longer if they will automate, only when and to what degree. One Minnesota manufacturer invested $250,000 earlier this year in a robot that can handle many of the repetitive tasks in his shop as a result of the ongoing struggle to find skilled workers.  At FABTECH, we not only want to support the future of the automation world, but also, help bridge the skills gap most everyone in our industry faces.

With 1,500+ exhibitors spread over 650,000+ net square feet of floors space, FABTECH is the place to see the latest in technological advancements. FABTECH also provides 100 educational sessions and expert-led presentations covering the latest trends and technology in the metal forming,  fabricating, welding and finishing industries.

In addition to all of this and more offered at the 2015 show, FABTECH show cosponsors AWS, FMA, SME, PMA and CCAI aim to support the future of the manufacturing industry with each of their respective educational foundations/charitable organizations. These manufacturing industry organizations are responsible for numerous scholarships, manufacturing camps for students, and educational programs that are essential to closing the skills gap and advancing manufacturing in America.

Register today! Complimentary advance registration for access to the exhibits is open until November 6, 2015. Registration after this date and onsite is $50. Find event details and register to attend the expo at fabtechexpo.com.

FABTECH-ers Start your Engines

Maximize your Show Experience with Exciting Special Events

Legendary NASCAR driver, Rusty Wallace will kick off FABTECH 2015 in the fast lane Monday, November 9 with a keynote presentation demonstrating that anything is possible through the power of teamwork. Wallace’s 25-year career included a Rookie of the Year Award, 55 Cup wins, and recognition by NASCAR as one of the 50 greatest drivers of all time. Now an ESPN/ABC sports commentator, he brings his knowledge of NASCAR to television audiences everywhere, announcing the most exciting races, including the Indy 500. Rusty will use lessons from racing to leave attendees more motivated to run a winning organization.

Later in the line-up the Professional Welders Competition gives spectators the opportunity to cheer on contestants as they compete to earn the title of Best Welder in America. Competitors will make a single-pass SMAW weld with E7018 on low-carbon steel. Speed and quality will be the criteria. Winners will be announced on Wednesday, November 20 at 11:00 a.m. Professional welders interested in competing can sign up onsite ($15 entry fee) to compete for a $2,500 first prize, a $1,000 second prize, and a $500 third prize.

The excitement continues after show hours on Tuesday, November 10 at the annual FABTECH Industry Night Party at Lucky Strike in downtown Chicago.  Enjoy food, drinks, bowling, billiards and more all in the company of colleagues and new friends. We expect this to be a sold out event, so get your tickets early when you register for the show.

With all of this and more you don’t want to miss FABTECH 2015. Register today!Complimentary advance registration for access to the exhibits is open until November 6, 2015. Registration after this date and onsite is $50. Find event details and register to attend the expo at fabtechexpo.com.

Stamping 101: Anatomy of a Mechanical Press

Stamped components are made by forming, drawing, trimming, blanking, or piercing metal—in sheet or coil form—between two halves (upper and lower) of a press tool, called a die. The upper member (or members) are attached to slide (or slides) of the press, and the lower member is clamped or bolted to the bed or bolster. The die is designed to create the shape and size of a component. The two halves of the die are brought together in the press. Both force (load) and accuracy are required to achieve the repeatability and tolerance demands.

 

Stamping press functions

Editor’s Note: STAMPING Journal® will explore hydraulic press capabilities, the differences between mechanical presses and hydraulic presses, as well as servo and pneumatic presses in “How to select a press,” which will be published in the March issue.

Understanding the fundamentals of press technology requires, at minimum, that you be able to answer some basic questions:

  • What is stamping, and what does a stamping press do?
  • What materials are stamped most commonly?
  • What is a die or press tool, and how is it used?
  • What are the main types of stamping presses?
  • What are mechanical press drives, and how do they work?

Before you can examine the structure of a press, you must take a step back and look at a stamping press’s function.

Stamped components are made by forming, drawing, trimming, blanking, or piercing metal—in sheet or coil form—between two halves (upper and lower) of a press tool, called a die (see “Stamping 101: Die basics,” page 22). The upper member is attached to a slide, and the lower member is clamped or bolted to the bed or bolster. The die is designed to create the shape and size of a component, repeatedly, and in quantities that will meet production demands. The two halves of the die are brought together in the press. Both force (load) and accuracy are required to achieve the repeatability and tolerance demands for the final stamped and assembled part.

Stampings are manufactured from many different materials. For example, beverage cans are formed from aluminum; many automotive parts are stamped from high-strength steels; doorknobs and lock mechanisms are stamped from brass. Structural parts, such as nail plates and joist hangers, are stamped from galvanized steel.

Sizing the Die to the Press

To size a die to a press, two calculations need to be performed. The first is tonnage (force) and the second is energy consumed. Every press in the world is rated by the tonnage (force in tons) that it can apply from bottom dead center (BDC) of the press cycle to BDC of the same press cycle.

The tonnage rating of a press must not be confused with the energy generated by the flywheel of a press. Each press has a tabulated graph of energy supplied by the press manufacturer—and each one is different. This is because flywheel-generated energy is dependent on the size of the flywheel and drive ratio. This also makes a big difference in the cost of a press.

Due diligence is needed when sizing a die. Many engineers who are very experienced in die design or in production or in press procurement but who are not experienced in all fields fall into the trap of considering only one of the two calculations. This question is then asked too late in the day: “Why can we not run this part?”

Press Drives and Frames

Presses fall into four main categories—mechanical, hydraulic, servo, and pneumatic. Each category derives its name from the drive source that generates the pressure (force) on the die to form the finished stamping. Each category can be further divided into one of two different frame designs: straight-side or C-frame. Each type of press can have single- or double-slide (ram) connections. A low-tonnage press can have a single- or double-ram connection depending on whether the accuracy required justifies the additional cost of a double-ram connection.

Straight-side presses have two sides and four to eight guideways for the slide. This reduces the deflection and enables them to handle off-center loads better.

 

Figure 1In a non-geared drive, the flywheel, clutch, and brake are located on the eccentric or crankshaft. As a rule of thumb, full press energy is available between half of the top press speed and the top press speed.

C-frame presses are shaped like the letter C or G, and most are manually operated. Because of its open form, a C-frame press is subject to higher deflection under off-center loads than a straight-side press. The slide is guided by two V-guides or box guides.

Other types of presses, such as transfer, hydroform, hot forge, and friction screw, are built for special applications.

Mechanical Press Drive Transmissions

Mechanical presses also can be categorized by the type of drive transmission that exerts force on the die: flywheel, single-geared, double-geared, double-action, link (also called alternative slide motion [ASM]), and eccentric-geared.

All are powered by an electric motor that drives a large flywheel. The flywheel stores kinetic energy, which is released through various drive types. For each 360-degree cycle of the press, or stroke, energy in the flywheel is consumed as the part is made in the die. This causes the flywheel to slow, usually between 10 and 15 percent. The electric motor then restores this lost energy back into the flywheel on the upstroke of the press. The press is then ready for the next cycle.

If the percentage that the flywheel slows (slowdown), determined in strokes per minute (SPM), is greater than 15 percent, the electric motor will not have enough time to restore this lost energy, and the press will slow down too much. After several strokes, the press will jam on BDC. This occurs when the die tonnage or energy has been calculated incorrectly.

To stop and start the press, you use an electronic control to a clutch and brake, which in turn disengages the flywheel to the press drive. Most clutches and brakes are spring-applied and have either pneumatic or hydraulic releases. The stopping time of the clutch and brake is critical in determining both the speed that the press can be run and the safety of the operator and die.

Flywheel-drive Mechanical Press. Presses with flywheel drives are used for piercing, blanking, bending, and very shallow drawing with progressive dies. The normal press tonnage is between 30 and 600 tons. They run at high speeds—125 to 250 SPM on the low end, to speeds in excess of 1,000 SPM on the high end. Press stroke length is always kept as short as possible, as this affects press speed. The average stroke is 2 inches. If more energy is required at the lower speeds, an auxiliary flywheel can be added to the drive. However, the energy will never reach that of a geared press.

A flywheel-driven press normally is rated at full tonnage at 0.062 in. from BDC of the press cycle to BDC of the same press cycle. The flywheel, clutch, and brake are located on the eccentric or crankshaft. As a rule of thumb, full press energy is available between half of the top press speed and the top press speed. However, it is best to check with the press manufacturer for confirmation.

You need to check die calculations carefully when the material is thicker than the press-rated capacity. You must become aware of what to do with high snap-through (reverse loads) and press vibration when using ultrahigh speeds.

Flywheel presses are designed with dynamic balancing of the upper die and press slide (ram) weight using an opposing force. Without this opposing force, the press would walk around the floor at high speeds.

 

Figure 2This is the most popular press drive used by contract stampers in the automotive industry. It can be run at continuous speeds down to 28 SPM, although typical press speed range is 40 to 80 SPM.

Single-geared Mechanical Press. This is the most popular press drive used by contract stampers in the automotive industry. The tonnage ranges from 200 to 1,600, with a two-point connection to the slide. The gear ratio allows the flywheel to run fast, maintaining energy, while the press speed is much slower than a flywheel machine. Single-geared presses normally are rated at full tonnage between 0.250 and 0.500 in. from BDC to BDC. The correct rating to choose for your application depends on the die’s energy requirement. This rating will make a difference in press price and drive size.

A single-geared press is used for progressive stamping with dies having shallow draw or forms with piercing and blanking. This type of press drive transmission can be run at continuous speeds down to 28 SPM. A typical press speed range is 40 to 80 SPM with a 12-in. stroke. Remember the rule of thumb regarding energy—full press energy is available between half of the top press speed and the top press speed.

Always look for a press with a twin-end drive that has opposing helical gears with an eccentric shaft. This will improve accuracy, reduce deflection, and increase longevity.

The single-geared drive can be fitted with an alternative slide motion (ASM), or link drive.

Double-geared Mechanical Press. This press is used when a continuous production speed of lower than 28 SPM is needed. It is good for heavy-duty applications, especially for stamping high-strength steels. The drive gear ratio allows the flywheel to maintain its speed while the press runs slower than both the flywheel and single-geared press. Depending on flywheel size, very high energy can be generated with this type of drive. Press tonnage is from 200 to 1,600, with a two-point connection to the slide.

A double-geared press drive is good for transfer die work. Transfers typically run at 15 to 30 SPM. Presses with this drive normally are rated 0.500 in. from BDC to BDC. Some presses have a special drive rated at 1 in. from BDC to BDC; it is used for drawing, forming, blanking, and piercing with transfer and progressive dies.

The drive can be fitted with an alternative slide motion, or link drive.

Link Drive, or Alternative Slide Motion. This option allows reduced slide velocity during the working portion of the press cycle. It also may allow up to a 25 percent increase in production.

Eccentric-geared Mechanical Press This type of press and drive is used where a very long stroke is required — normally in excess of 24 in. All of the features of a double-geared press apply to this drive design; however, accuracy is not as good as an eccentric-shaft press because of the clearance with the arrangement of the gear train and the additional clearance needed in the slide guiding gib adjustment.

Double-action Slide. This press has two slides—one slide within the other. Each slide has two connections to the eccentric shaft. The stroke of each is different and timed so the outer slide is the blank holder while the inner slide completes the drawing operation.

 

Figure 3This drive is used when a continuous production speed of lower than 28 SPM is needed. It is good for heavy-duty applications, especially for stamping high-strength steels.

A double-action-slide press is used in deep-draw applications, such as beverage cans. In addition, it is the first press in an automotive press line for drawing the outer skin panels of cars.

Hydraulic Press

Hydraulic presses have advanced dramatically over the years with new technologies and improvements in electronics and valves. They are especially suitable for deep-draw applications, because they can apply full tonnage over the complete length of the stroke.

In addition, you can program the velocity that the slide travels as it closes the die.

You can program the return stroke for fast return, and you can adjust the stroke to any distance you need, thus achieving the maximum SPM available with the pump design.

A hydraulic press is powered by a hydraulic pump to a hydraulic cylinder or cylinders that drive the slide down. Pressure can be preset, and once achieved, a valve can activate pressure reversal so no overload can occur. With this press design and its applications, the die tends to guide the press, so the guiding systems do not have to be as accurate as with a progressive-die mechanical press. Hydraulic press production speeds normally are lower than those achieved with a mechanical press.

Increasing Stamp Press Productivity

An appliance plant with 80 to 100 presses in operation is likely to buy new presses regularly. Under these circumstances, it makes good sense to pursue aggressive productivity goals inch by inch through steady advances in such prosaic concerns as machiner ergonomics, prventive maintenance, tooling efficiency, and material quality.

To the pilots of high-performance aircraft and operators of stamping equipment, one rule holds true—keep surprises to a minimum.

This is especially true for stamping operations in the appliance industry. With the exception of the development of programmable electronic controls, manufacturers have made gradual but consistent performance upgrades that have allowed them to minimize capital equipment expenditures while maximizing the performance of stamping presses, transfer feed systems, and tooling.

Recognizing that a stamping press has an average life expectancy of 20 to 25 years, an appliance plant with 80 to 100 presses in current operation is likely to buy new presses at regular intervals. Under these circumstances, it makes good sense to pursue aggressive productivity goals inch by inch through steady advances on such prosaic concerns as machine ergonomics, preventive maintenance, tooling efficiency, and material quality.

Quick Die Change Systems, Pneumatic Lifters

The increased operating speeds offered by transfer presses are one source of improved productivity. Another factor that influences productivity is the Quick Die Change system, which can sometimes make a pressroom feel like the flight deck of an aircraft carrier. In five minutes, quick clamps are released, the transfer rail is disconnected, tooling exits the press on one side while new tooling enters from the other side, and the press is ready to run again.

The trend toward transfer presses is largely a response to intense competition in the appliance industry. Whether the part in question is a large dryer panel or the inside liner of a refrigerator, producing 18 to 20 parts per minute (PPM) on a transfer press equipped with electronic controls is not unusual. This contrasts with speeds of 8 to 10 PPM on a typical tandem line.

Pneumatic Lifters

Improvements in transfer press technology involve more than big ideas, such as electronic controls and Quick Die Change systems. When pneumatic lifters replaced traditional spring lifters more than 20 years ago, part quality and production speeds increased substantially.

Pneumatic lifters, charged by nitrogen, allow the stamping manager to apply pressure discretely according to the operation under way, the geometry of the part, and the material being formed. By holding the part in place, the lifters secure it for the next operation. After the operation is performed, the lifters quickly elevate the newly formed piece for transfer to the next operation.

Pneumatic lifters provide part stability and quick part release, which are important contributions to press speed. After all, a part cannot be stamped if it is bouncing around on the tooling.

Ergonomics

Increased speed and overall press flexibility are the macro side of transfer press improvement, but the best stamping operations also benefit from improvements at the micro level.

For example, not long ago, managers bought presses, and operators ran them. Now, press purchase and installation is an open process in which the operator plays a critical role. A multitude of concerns is now weighed against the cost of a new press, and every aspect deserves consideration.

Ergonomics is more important than ever. One appliance manufacturer even builds prototype panels for the operator controls of a proposed new press to minimize wasted motion. Every operator who will be working with the panels works with the prototype to ensure that the position is proper, the functions are correct, and the buttons are in the right place. By allowing operators to get involved with the planning and design of the prototypes, the company reduces any motion that is not related to production during stamping.

The philosophy of controlling nonproductive factors even extends to controlling noise and dust. Press gates with special sound-dampening qualities help to keep a pressroom quiet while minimizing the effects of dust and grime on equipment, the labor force, blanks, and finished parts.

Catering to Customers

As competitive pressures mount and consumers demand better products, stamping equipment manufacturers can expect unusual requests from their appliance industry customers. For example, one stamping press manufacturer sends its engineers to appliance manufacturing plants to supervise press rebuilds. In the past, such projects were usually handled at the press manufacturer’s plant. However, doing the job at the customer’s plant eliminates the time and costs involved in shipping the press to the press manufacturer.

In this case, the press manufacturer shipped the correct materials to the customer, built to the customer’s specifications, and sent engineers to supervise the customer’s work force in executing the project.

Material Improvements

The productivity of stamping operations is also boosted by using better materials. Cold-rolled and hot-dipped galvanized steel are the materials most commonly formed by appliance manufacturers. Improvements in the steel manufacturing process have lead to steel with more consistent chemistry. Continuous casting, a process developed in the 1960s, allows a mill to use additives such as aluminum to attain desired characteristics. Kilned steel is one such product that is used by appliance manufacturers.

Adding aluminum to steel de-oxidizes it and prevents it from gradually hardening, which makes it more difficult to work. Kilned steel ordered for Just-In-Time (JIT) delivery now has the same chemical properties from day to day, week to week, and month to month. Consistency in the steel eliminates many production problems such as ragged edges on parts or accelerated tool wear that used to result from age hardening of the steel.

More to the point, using a more consistent steel enables appliance product designers to use thinner-gauge steel for exterior parts. This fits well with the overall trend in the appliance industry to reduce the amount of steel that is used. Using blanks made of thinner steel also places fewer demands on the stamping equipment, thereby increasing the life of tooling and stamping presses.

Quality initiatives in the steel industry are boosting productivity. The surface of the steel being shipped to appliance manufacturers has far fewer impurities today than it did years ago. Paint adheres better to a product that is free from grit, oil, or dust. When paint adheres better, part rejects are reduced.

Sheet metal remains the go-to material, although research into plastics and prepainted metals continues. But because much of the painting equipment in large manufacturing plants has been installed, debugged, and paid for, little likelihood exists that other materials will achieve greater market share in the near term.

Conclusion

From better materials to improvements in press technology, die design, and tooling, stampers in the appliance industry are showing that metal forming innovations come in many shapes and sizes — and the fewer surprises, the better the results.