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Upgrading Stamping Line Controls

March 2013

Simple upgrades can boost productivity while lowering costs and help with OSHA compliance

There are many reasons to upgrade a stamping line’s controls. Along with increasing productivity while getting a more efficient operation, government compliance also dictates that controls might need to be replaced.

“There are many benefits to retrofitting press controls, and only one of them would be increased production,” says Lance Curtis, VP of sales at Link Systems.

“Another important reason for retrofitting presses with automation controls is to integrate monitoring throughout the press process. It not only allows a customer to control all the aspects of the stamping process from one operator terminal that would include things like transfers or feed lines or stackers and destackers, but it also gives the staff the ability to monitor certain processes such as die protection and tonnage monitoring,” he adds.

“Another reason would be for more efficiency, being able to produce parts without defects. It would allow a company to put processes in place that would give the operator positive control of every aspect of the stamping process. This would allow them to monitor and to be sure that the part quality is there at the end of the process.”

Ashok Bhide, Marketing Manager at Wintriss Controls adds that replacing controls could be done for another reason. “One of the most important ones is to upgrade safety and comply with current standards and regulations. For stamping presses this is very important. Mechanical presses are considered one of the most dangerous manufacturing machines, and in fact, power presses are one of the only machines that have their own specific regulations, CFR 1910.217.

“This regulation enforces how a press control must work on a part-revolution clutch-style stamping press. Redundancy and self checking are required in all new retrofitted or OEM control.”

Jim Ward, sales manager at COE Press Equipment Corp. says that replacing the controller can provide a relatively easy way of simplifying setups while increasing functionality to improve productivity.

COE Press Equipment

Many new servo controllers are designed to be quickly implemented into existing or new lines, with the upgrade done over a weekend, says Ward. Many servo feeds in operation today were introduced when servo technology was being developed. While they were a great replacement to the old air and mechanical feeds, many were built on unsupported hardware and software platforms. A stamper can face extended downtime in the event of the failure of a critical drive, motor or motion controller.

He adds that many original straighteners and reels in coil feeding systems were designed with simple drive mechanisms, while today’s variable-speed controls are programmable. This allows the development of custom parameters to optimize machine performance used in uncoiling and straightening functions to provide the proper torque necessary for these operations. 

“Many roll feeds in operation today have outdated operator interfaces. These are often simple devices that only offer basic set-up functions of feed progression and speed percentage, limiting their effectiveness in today’s stamping operations. With an upgrade to a modern device, users gain many new features such as storage recipes, operator prompts, servo-feed diagnostics, multi-lingual programming and direct downloading of parameters from the host press. All of this helps to reduce set-up time, improve consistency and raise productivity,” notes Ward.

Loop-control upgrades can help with accurate sensing of the loop position and precise feedback to the straightener or reel drive, which is crucial for effective operation of the coil feeding system, he adds.

Where original loop-control systems are often simple on/off switches or potentiometer devices, modern-loop controls are based on ultra-sonic, photo eye and laser-beam technology. These provide non-contact for higher quality requirements. Loop height and response output signals are programmable to achieve optimum coil-line performance for each job setup.

For servo feeds, COE offers its ServoMaster Touch Controller, featuring a 5.7 in. color touchscreen interface. It offers users a digital solution with full integration of critical components for the speed, precision and power required for a variety of feeding applications. Its Servo Feed Interface works with major press controls to provide the operator with a single-point entry for the press and servo feed.

COE Press Equipment uses a wide range of hardware from a variety of control companies to retrofit presses and press lines. Its systems provide set up and changeover efficiency for the uncoiling, straightening and feeding process but not for the press itself.

COE uses PLC based operating systems and touchscreen operator interfaces for easy usage. Line automation systems allow the operator to manage multiple devices and machine axis. The feedline will automatically control functions such as roll-feed passline height, straightener/breaker roll positions, breaker roll on the fly adjustments, coil center position on reel, loop-depth position, calculated linespeed control, automatic brake tension and modulation, tailout operations and others.

COE sells the equipment and does retrofit installs throughout North America using its team of highly skilled professionals.

Wintriss Controls

“Our clutch/brake controls have been designed to meet both OSHA and ANSI guidelines for stamping presses for the last 30 years. And believe it or not there are still many machines that have old relay controls that might not comply with the OSHA regulations,” says Bhide.

The company makes both safety and automation products such as its SmartPAC 2 Press Automation Control that offers die protection, along with programmable limit switches, tonnage and press monitoring and many other important features. It has the ability to interface with auxiliary automation equipment such as a press’ servo feedline, placing all the stamping setups on one screen.

“Because the SmartPAC 2 is memory-based, it downloads setups to the feeder and other devices every time a tool is changed out. It saves all the parameters for each tooling system. If you’re going to change the feed length for example, when you change your dies, it will download the feed information to the servo feeder,” remarks Bhide.

The SmartPAC 2 automation control can monitor the entire press line and any other automation, including progressive or transfer-style tooling to move parts within the press and die.

“The clutch-brake control primarily deals with the safe operation of the press’ clutch-brake control. We needed a dedicated product just to handle the press control part because of its impact on safety and the need to comply with the rigid safety mandates. We don’t mix this objective with die protection or the servo feeds or any other part of the line,” he says.

Bhide says that new controls can easily boost stamping productivity.

“The SmartPAC 2 and even the clutch-brake control play into this, because they have lots of features that allow productivity improvements. But mostly it’s the SmartPAC 2, because it has a die protection capability along with programmable limit switches.

The SmartPAC 2 can also be configured with a tonnage monitor that will ensure that the tonnage developed every stroke is within a window of tolerance, or it will stop the press. This also helps to comply with regulations that mandate the press be run within its design limits. A shut-height and counterbalance adjustment option can also be added that will automatically adjust them after every die change.

One of the biggest things achieved with this type of automation is what is called quick die change. SmartPAC 2 reduces the time needed to change dies because all the settings are already in the control’s memory. The operator doesn’t have to reprogram everything from scratch when a changeover occurs.

“And new controls will allow your equipment to run faster. With press and die monitoring, the control looks after the operation instead of the operator. Therefore you can run the press faster, because the sensors and control react much faster than an operator can be to stop the press.”

Wintriss Controls also provides data collection software that talks with virtually all the machines in customer’s plant(s) and brings real-time information to anybody’s PC in the company who needs it. Downtime reasons are accurately identified, and production reports are generated and distributed automatically.

The company has a network of representatives across North America and Mexico that it works with and Wintriss personnel train them to do retrofits.

Link systems

Press controls actually are designed to enhance the press itself, says Curtis. “However, with automation controls now in the integration of these press controls with feeders, stackers and destackers or transfer lines or whatever, they have positive control over the entire feedline. Now that’s not to say that a press control replaces the controls for the feed lines or any other auxiliary equipment, but it integrates with these and gives the operator the ability to monitor everything from one central location or one operator interface terminal,” he adds.

In fact, Curtis says that with its controls, press line monitoring can be done at a remote location. “We have a program called LinkNET 3 that allows remote location viewing of the stamping process. If there are several plants within a corporation, our system will give them a central monitoring location. All these divisions will submit information back and forth and then the information can be compiled and processed. This information can be used to improve the processes or to simply know what the production rate is in a particular plant.”

Curtis mentions that if the total process is looked at properly, the press control is the central brain for the entire stamping process and everything can be monitored right through its control.

“I see customers often cutting corners on controls when a press control should be the focus when doing an upgrade. It will give them better process monitoring along with a greater capability of collecting metrics, so that they can improve their process constantly,” he mentions.

Link System controls are not PC-based, but are dual-micro-processor controlled, which is different than a PC or PLC. This actually offers two controls in one package that monitor the same functions, says Curtis. These controls provide a redundancy. If there is a deviation between the two microprocessors when monitoring something, the press control will lock itself out and no longer allow the press to stroke until the issue is resolved.

Link Systems has its own installation crews for stamping line retrofits. It’s not exclusive however, mentions Curtis. “If a customer or a vendor has their own preference, and they want to put their own controls on, we certainly don’t have a problem with that,” he notes.

Coe Press Equipment Corp.
Link Systems
Wintriss Controls