Five Reasons Why Now is the Right Time to Consider a Press Retrofit

Via our strategic partners at Bosch Rexroth, we bring you a break down of 5 reasons why now is the right time to retro fit your press!

Bosch Rexroth and Hydrotech application engineers all agree: Presses are hard-working machines, and many have been in service for years—some since the early 1950s.

As a press ages, 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 parts you need are not even available anymore.  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 can often 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 do we really need?  Can a retrofit bring older machines into Industry 4.0?

The 5 reasons why now is the right time to retrofit your outdate press:

• Upgrading or switching technology may improve performance more than you thought
• Retrofitting improves worker and machine safety
• You can reduce cycle time and lower overall operating costs
• You can improve process visibility and react faster to production deviations
• Executing a retrofit will help you consider technology and capability upgrades in other systems and machines

But what does that all mean?  Well, let's break it down!

1. Upgrading or switching technology may improve performance more than you thought.

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.  For example, 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 can also 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 drastically improve energy efficiency. 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 the right level of performance upgrade to suit your needs.  Retrofitting out 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.  Rexroth’s EMC Electromechanical 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.  So, 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. Retrofitting improves 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.  And 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 cause you to miss the potential for healthy productivity upgrades.  For example, until 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, such as Rexroth’s Safety on Board, 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, Safety on Board lets you stop operation of moving parts so that you can repair the machine safely while it is still under power.  Once repair personnel has 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.  Rexroth press safety blocks, for example, 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.  However, safety should always 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 I/O technology is constantly being developed, 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 production. 

3. You can reduce cycle time and lower overall operating costs.