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Controls: Don't Disable

By: Louis A. Kren

Saturday, July 1, 2017
 

Outfitting or upgrading a press line with capable control technology, as is the case here, is only step one. Step two: using it. Disabling tonnage monitoring or die-protection functions, for example, will keep production moving, but only until catastrophe occurs, and along the way part quality and press reliability surely will decrease.
Press controls have advanced to the point where they can communicate with all line components, and even have the ability to alter press tooling on the fly. Controls have adapted to the increased use of cellular manufacturing, and the need to communicate more closely with the entire cell. They provide real-time information on job status, and integrate with MRP and ERP systems, enabling improved tracking and ordering of materials, for example, and aiding company decision makers with scheduling as well as tool and equipment performance and maintenance needs.

Diagnostic tools in the controls show input and output status using architecture that enables rapid troubleshooting. These tools enable safe I/O examination without the need to enter hot electrical panels.

Controls today provide an abundance of historical data used to create baselines and chart performance for a variety of uses. Combined with robust sensoring, they assist in error-proofing, allowing metalformers not only to verify good parts, but also to receive verification reports generated by automated systems. No longer do controls offer only stroke counters, but good-parts counters as well, while making sure, via control of chutes, conveyors and part-ejection mechanisms, that good and bad parts route accordingly. They’ll assess coil entering the press and, via servo and stepper motors, automatically adjust wedges in the die to account for variations in material thicknesses.

In short, controls can set, run, correct and report across an entire manufacturing cell or press line. Everything above has been documented in the pages of MetalForming. We know that controls have tremendous capabilities, and provide powerful tools for operators and on up to the C-suite. But outfitting or upgrading a cell or line with capable control technology is only step one. Step two: using it.

Blocking Data Hampers Improvement

“We see a disturbing trend, what I call acceptance mode,” shares Dean Phillips, sales engineer for Link Systems, Nashville, TN. “Companies will install a tonnage monitor or some type of die protection, then proceed to gather information. At some point, these companies determine that they’ve gathered all the information they need, and then will shut down or disable those data-gathering and control mechanisms.”

Phillips has seen some of the largest manufacturers, including OEMs with millions of dollars tied into their press lines, shut down these systems. After recalls, he notes, some of these manufacturers blamed the recalls on not following their own quality procedures, i.e., shutting down monitoring functions.

“Manufacturers are not using the equipment they have,” Phillips says. “In one plant, every tonnage monitor on every press was disabled. Too often, a stamper or fabricator will say, ‘We’ve incorporated Lean and Six Sigma, so we’re done.’ But that fact is, you are never done. You have to keep working on it to continuously improve. The same is true in monitoring and data gathering.”

As business cycles fluctuate, so, too, does attention paid to monitoring and data gathering by manufacturers.

“When business is down, they’ll get rid of aspects that don’t show a true ROI from a production standpoint,” says Phillips. “You’ll see engineers assigned to Lean or Six Sigma transferred out while these teams are abandoned, with the idea that they’ll be resurrected when things pick up, but that never seems to happen. We see the same with tonnage monitors, for instance. Not using the tools available is an alarming situation.”

Don’t Wait for Pain

The problem? “People do not react to pleasure, they wait for that moment of pain,” Phillips says. “It happens over time. Presses keep pounding to meet production needs. When production increases, downtime for scheduled maintenance is sacrificed. Manufacturers will say that they don’t have the time for proper maintenance of machinery. If maintenance personnel come around to take down a press or other equipment for regular maintenance, production won’t allow it. It is accepted that production always trumps maintenance. Of course you can wait, but at a certain point, when dies are crashing and quality nosedives, waiting no longer is an option. At this point maintenance is unplanned, time-intensive and costly.”

Big-Time Assistance for Operators

Part of the problem, in Phillips’ view, stems from the ongoing skills challenge as metalformers and fabricators seek to fill positions with qualified applicants and retain skilled workers.

“Whether through a lack of skills or a lack of training once they are hired, sometimes employees are not properly prepared for the things they need to do,” he says.

Where controls providers and other suppliers to the industry can help is by making equipment operation and monitoring as intuitive as possible.

“We see operators hunting and pecking at user interfaces to find the menus and pages they’re looking for,” says Phillips. “Back in the 1970s and ’80s, controls may have had indicator lights and, at best, a short one- or two-line display describing equipment status. A light would indicate an e-stop, for example, and then a maintenance technician would arrive to troubleshoot and, after a time discover that air pressure had not been turned back after machine shutoff, or a die block had not been plugged back in after a die change. Now, controls manufacturers provide prompts that, if a press or piece of equipment is not running, indicate where the problem is and here’s what must be done: ‘Lubrication-oil level is low.’ ‘Turn the lubrication motor on.’ ‘Turn the air pressure on.’ Whatever that may be, controls now alert operators and take them step-by-step through a sequence to satisfy the alert condition.”

No need for a time-consuming once-over by the maintenance department.

“Controls still must evolve to become more intuitive, to provide users with tools to assist in making employees and processes as efficient and productive as possible,” Phillips says. “Controls now can walk the operator through a process and provide usable information. A problem with counterbalance? The control is specific to the input for the counterbalance, perhaps a low reading on a pressure switch, which indicates a problem with the air pressure itself or an incorrect pressure setting. The control recognizes situations, and prompts and advises accordingly. This is a good example of how controls have become more intuitive and now incorporate prompting levels that help inexperienced operators find solutions. But we need to keep moving forward.”

Besides providing assistance on the shop floor with improved messaging and prompting capabilities, controls act on monitoring functions by keeping management informed, another reason why manufacturers should not disable monitoring, according to Phillips.

“Networking systems communicate when tonnage monitoring or die-protection functions, for instance, are disabled or turned off,” he says. “This assists with troubleshooting. If a die crashes, you’ll know that tonnage monitoring was disabled due to overloading conditions. The solution was to ignore the problem as opposed to taking action to reduce the amount of tonnage required. Users can set up control systems to prevent bypassing or disabling of monitoring functions in certain modes of operations. Here, disabling is prevented, or if it does occur, the equipment will not operate. Controls provide a system of checks and balances to take action and prevent future calamity.”

Keep Complex Lines Productive

The continued ascendancy of hot-stamping and servo-driven press lines, processes that add complexity by orders of magnitude despite their seemingly effortless performance when running optimally, further point to the need to deploy, and use, high-performance controls. With so many process inputs, controls increasingly crunch incoming data to monitor, protect and optimize performance of these lines, including complex ancillary pieces of equipment. Data gathering, and actions based on that data, are the purview of modern press controls. And, of course, controls work best when there’s data to be gathered. With that in mind, Phillips offers two words of advice: “Don’t disable!” MF

 

See also: Link Systems

Related Enterprise Zones: Sensing/Electronics


Reader Comments

Posted by: Doug Cox on 7/12/2017 10:36:20 AM
Thanks for the reminder even though I believe we push for safety and NO short cuts to save our workers and machines any harm.

 

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