Menu

Five reasons to retrofit a press

Instead of replacing a press, which can be costly and time-consuming, retrofitting them might be a better solution.

Brian Van Laar, Andrew Binversie, Nathan Davis, Monte Swinford, and Ken Rayden
04/11/2018
Five reasons to retrofit a press

Since most presses are designed for years of service, retrofitting an older machine often can bring surprisingly cost-effective benefits that can add another decade or more to a machine’s service life. Courtesy: Bosch RexrothPresses are hard-working machines, and many have been in service for years—some since the early 1950s. As presses age, problems can occur, and even the most robust of presses will eventually require retrofitting or replacement. The initial symptoms may simply be increased or more frequent downtime while components are replaced. 

As time goes on, however, technological obsolescence may mean that the needed replacement parts no longer are available.  Perhaps more importantly, as technology advances, a 1950s-era press may not be able to make parts that meet the requirements of the 21st century. Modern automotive parts are an excellent example: sheet metal used in today’s cars is significantly different from that used several decades ago, and controls from presses of that era simply do not offer the type of precision needed to create today’s intricate designs. 

So why not simply replace the machine with a new one? Cost is an immediate consideration for most, especially if the plant has a good number of machines that will need to be replaced. It might also take longer to put a new machine into an established production flow, and result in more downtime than a retrofit might cause. Extrusion presses and forging presses, especially, are substantial pieces of equipment that might cause considerable disruption to facility operations if replaced outright. Of course, there are times when a new machine is the answer. But since most presses are designed for years of service, retrofitting an older machine often can bring surprisingly cost-effective benefits that can add another decade or more to a machine’s service life.

In addition to understanding the needs of the application and the company, manufacturers should analyze any available data and known pain points to make an educated decision. What are some technology choices to make when considering a retrofit? Can it be accomplished without a lot of downtime? How much of an upgrade in functionality is really needed? Can a retrofit bring older machines into the age of the Industrial Internet of Things (IIoT)? 

Here are five reasons why a retrofit is both possible and cost-effective.

1. Improved performance 

Technology is advancing and provides a wider range of choices than ever. In certain cases, switching from older technology may be the best move for machine performance. Upgrading the hydraulics in an existing machine from traditional hydraulics to servo-hydraulics or a hybrid system can bring a substantial upgrade in machine capability: speed control, force control, torque control, and other enhancements all come from upgrading to a servo system. Adding a servo motor to a pump to create a hybrid system can yield similar benefits.

Upgrades in linear motion technology also can bring significant benefits, especially with older presses. 

For example, if a press has an older plain or solid type linear bearing, swapping the plain bearing with a modern rolling element linear bearing can improve energy efficiency drastically. Due to the design of a plain bearing, it generates surface-to-surface contact, increasing friction and the energy required to power it. 

Modern ball and roller bearings offer a nearly limitless variety of options too, in precision, sealing capabilities, bearing size and shape, so it’s easy to find a suitable level of performance upgrade. Retrofitting the older components provides cost-saving benefits to the machine, extending its life significantly, and improving overall production.

For smaller presses, a technology switch from hydraulics to electromechanical technology may bring additional benefits, such as noise reductions and improved factory floor cleanliness. There’s no more hydraulic fluid to deal with, and today’s electromechanical cylinders provide high-force, precision movement with extremely quiet operation. Some cylinders use either ball or roller screws depending on the force requirements and reduce plant noise because there is no hydraulic fluid in action. 

Electromechanical technology has a limited force application range, however, maxing out at around 30 tons of force. Dynamic loads during operation and the required press duty cycle might reduce this even further. While electromechanical retrofits as a replacement for hydraulics are possible in a range of applications, the power density of hydraulic drives means that most hydraulically-powered presses will stay in the hydraulics family.

But even in these high-force applications, users still have options to reduce noise. Variable speed pump drives, like Rexroth’s Sytronix pump, for example, can achieve noise reductions of up to 20 dB in machine operation. When implemented in multiple machines within a single factory, the change in operator comfort and productivity can be considerable.

2. Improved worker and machine safety 

With the advancement of safety technology and additions to government safety requirements, older machinery, in its original state, may not comply with all of today’s regulations and may need to be upgraded to fit current safety standards. In simple terms, an aging machine can cause environmental and operational hazards such as oil leaks, loose wiring, or components that fail. 

While it can be relatively easy to make the necessary repairs to fix those types of problems, safety technology has progressed so significantly that taking such a reactive-only approach will miss the potential for healthy productivity upgrades.

A press retrofit is more cost-effective than replacing the entire machine, and can breathe years of new life into machines once thought to be long past their prime. Courtesy: Bosch RexrothUntil recently, the definition of “E-Stop” meant cutting power to a machine immediately. This proven and necessary feature not only prevents injury to the machine operator, but also protects the machine by stopping moving parts from crashing and causing further damage to the machine. Once repairs have been made, the machine is turned back on and, after a lengthy boot-up cycle, resumes operation. Safety today has advanced significantly beyond this.

Today’s safety technology eliminates the lengthy boot-up cycle by taking a much more sophisticated approach to locking out just specific aspects of the machine. Instead of having to cut power entirely, modern safety technology allows stop operation of moving parts so that the machine can be repaired safely while it is still under power. Once repair personnel have safely exited the machine, operation can resume without having to re-boot the entire machine. The time saved in waiting for the machine to reboot can result in a substantial improvement to production efficiency and increase the parts-per-minute capabilities of the machine to increase overall equipment effectiveness (OEE). Less downtime means more production.

In addition to control electronics, safety features also continue to improve in the machine componentry. Press safety blocks can be implemented into the hydraulic circuit of existing machines for added safety. Used mostly in down-acting machines, such as stamping lines, cold-forming machines and peripheral equipment, these safety blocks are retrofit-friendly components that can add a good measure of protection. 

Safety always should be viewed holistically when evaluating potential for a safety upgrade. If not integrated into the machine control, even simple upgrades like the safety blocks mentioned above will be ineffective. New controls, safety blocks, and safety programmable logic controller (PLC) or input/output (I/O) technology is being developed constantly, with each bringing new safety capabilities to the manufacturing sector. All the safety features and components can be implemented, but if they are not connected to a machine safety infrastructure, they are of little value to produc

Related News

Channels

Products

Visit Our Sites

Contact Us

Settings

Close Home
click me