Retrofitting old machines is a compromise, but with cost consideration it is often resorted to and not just by SMEs.
Retrofitting Old Machines
A sight to behold – bright airy factories, shiny shop floors with robots and automated conveyors, and a production schedule completed before time. No down time – this courtesy of the internet linked sensors that keep a check on equipment health and respond to the tiniest hiccup in supply or logistics. An enticing picture, isn’t it? An enticing picture or not, for most factories, the true picture is completely different. Many still have machinery that is several decades old and rarely are they equipped with the latest technology or sensors.
At a time when most manufacturers are adopting new ways to lower their energy footprints, using machine tools with features that help to reduce consumption of power and increase operational efficiency are gaining prominence. Frost & Sullivan believe the demand for machine tools in India could grow at a CAGR of 15 per cent a year. Nearly 60 per cent of this demand is met by imports today.
Most industrial equipment is intended and installed to last at least a few years. In that time, a lot of significant and new technologies are announced. Many manufacturers pursue ways to get the advantages of advanced-manufacturing technology without having to change current equipment that remains in fine working condition. Yet many of the prevailing machines were just not planned to support new technology.
Getting from where manufacturing is now to the factory of the future is possible and many have done it — but it isn’t as easy as adding a manufacturing version of a health tracker onto each piece of old equipment in a plant and calling it a day. It is expensive.
Isaac Brown, an analyst at Lux Research says, “Several factories have machines from 10, 20, 30 or 40 years ago. Plugging them into the Internet is completely not inconsequential – it’s not like connecting to a PC.”
Most small shops just can't pay for planned replacements, and so, nearly 75-85% of the machines operating for the last 20 years are still in use now. Manufacturers want to do the everyday jobs they've always done, but continue to capitalise on performance, and make the plant floor more transparent to other departments in the business.
When you consider an upgrade, and look for automation systems you have three options; either one may or may not work for your manufacturing unit:
- Tear and change the whole prevailing system
- Retrofit old system with new machinery, and
- Keep the old system running as long as possible.
However, everything else aside you need to consider the down time, life span of the new system, and the cost of change or retrofit.
Keep old system running: Fixing and maintaining broken machinery while running an old system can be a trial but it is not impossible. For example, if the spare parts you were searching for are no longer manufactured, you are likely to find the spare parts on the Internet through websites like eBay, Google Shopping, etc. The method of searching for and changing the part may help you save money in a few cases, but at some point, it will no longer be viable to keep repairing old machinery. So, though this strategy may work when you are in a fix, it is not a long-term solution you can bank on.
CNC retrofit: For a manufacturer, the machine tools are the most important and expensive pieces of equipment in the factory. These machine tools signify substantial investments and must consequently sustain their capability for several years. Keeping machines updated with the newest control technologies through a CNC retrofit is one way corporations are doing that successfully today. Other options like transformation and remanufacturing characteristically include a CNC retrofit.
What is it? A CNC retrofit usually updates the CNC, the spindle motor and drives, the servo motors and drives, and a portion of the associated wiring and related electromechanical components. Distinct from remanufacturing and rebuilding, a CNC retrofit doesn’t include any key upkeeps to the machine process. A CNC retrofit is not the same as a CNC conversion, where a labour-intensive machine is transformed into a CNC machine.
Presuming that the machine is in a good working condition, a CNC retrofit is the bottom price option used to augment the performance of a legacy machine tool. Most of the retrofitting is done at the machine’s site, which helps to avoid expensive machine rigging and cost of transportation while minimising the downtime though there could be some electrical subassembly that is done at the retrofitter’s shop location.
Reconstruction characteristically includes the mending or replacement of some damaged motorised gears such as lubrication pumps, ball screws, safety interlocks, hoses, guards, belts and electrical wiring. The reconstruct is done at the rebuilder’s business location, which means a manufacturer may incur additional transport and rigging costs.
Remanufacturing is one step further as it means to repair or replace mechanical components to make them as good as new or as per factory specification. The process may include complete disassembly of the machine, cleaning, inspection, repairs and painting. All air-filled, electrical and hydraulic systems will be upgraded. The machine could be altered or have motorised fittings added to re-purpose it for a new purpose. Remanufacturing takes place at the remanufacturer’s location for sure.
Taking a decision on whether retrofitting, reconstruction or remanufacturing will work will depend on the present state of the machine and the expected advantages from the investment done. Studying upkeep histories and part yield data may help you know the state of the machines’ mechanical systems. A ballbar analysis can be used to identify mechanical glitches. Companies that retrofit, reconstruct or remanufacture can help you evaluate the current condition of the machine and suggest an apt solution.
Advantages of a Retrofit
A retrofit allows a manufacturing unit to lower costs at the cost of reconstruction, remanufacturing or retrofitting is around 1/3rd or 2/3rd the cost of a new machine. What’s more, you can also save on new tooling needs, rigging, transportation, any alterations, modification of programs or processes, etc. A CNC retrofit, on the other hand, allows you to use the same equipment without too much of a downtime.
A retrofit includes an upgrade of the servo and spindle system in the legacy machine to a new high-speed digital system. This upgrade helps to increase the machine performance as well as keep a check on any critical glitches or variations while the machine is in use.
An upgrade allows you to improve your mean-time-to repair, as the updated machines will make it possible to alert operators of processes and downtime failures. Getting alerts helps to improve your response time to get the issues resolved to minimize downtime.
Decelerating the axis and spindles on the legacy machine means large scale power consumption as the old systems dump energy into renewal rheostats. Retrofitting with the current digital upgrades help to push the energy back into the line on slowing down. This system along with the improved machine processes of the CNC help to save power costs as much as 30--50 per cent.
Steve Mustard, the cyber security chair at the Automation Federation, was recently quoted saying: “It is tough to install IoT solutions together with old equipment. Most legacy systems were planned with specific needs in mind, like minimal transfer of data at comparatively long update rates. As a result, the structures are not as suited to a modern IoT and big data approach where large volumes of data are transmitted in real-time.”
However, there are no convenient options — each situation and machine is different. You need to understand the functions of your machines completely to know the metrics that must be traced. Only with experimentation and testing can you identify the right sensors or upgrade options that suit all your business needs and creating a plan to collect, filter and analyse the data collected.