Challenges of high-acceleration servo motors

As machine tools get faster and faster, there’s a growing need for high-acceleration servo systems. These servo systems obviously require more robust motors and mechanical components. 

What’s less obvious is that they also need power and signal cables that have been designed to withstand acceleration-related stresses.
 
Lapp's brand new new lineup of high-acceleration servo cables, includes ÖLFLEX® SERVO FD 796 CP.  

 
This high-acceleration cable’s features include extra-fine Class 6 copper stranding, polypropylene insulation, non-woven wrapping, tinned copper braiding and a polyurethane jacketing. The cable optionally contains either one or two control pairs.

The new cable supports accelerations in excess of 5g and travel speeds up to 5 m/sec. Travel distances can range up to 100 m. Intended for flexible applications, it has a minimum bend radius of 7.5 x OD.
 
Other than its outstanding ability to withstand high accelerations, FD 796 CP behaves much like any other high-performance servo cable. It resists oil and flame to UL standards. Temperature range for flexible applications is –40 to 80ºC.


If you’d like to learn more the cable design challenges that result from high accelerations, download our latest white paper.

New Servo Cables Withstand High Accelerations

As machine tools get faster and faster, there’s a growing need for high-acceleration servo systems. These servo systems obviously require more robust motors and mechanical components. What’s less obvious is that they also need power and signal cables that have been designed to withstand acceleration-related stresses.


At the IMTS Show next month (Booth E–4624), we’ll have Lapp technical experts on hand to discuss the effects of high acceleration motion on cable lifecycle and performance. We’ll also be showcasing our brand new lineup of high-acceleration servo cables, including ÖLFLEX® SERVO FD 796 CP.

This high-acceleration cable’s features include extra-fine Class 6 copper stranding, polypropylene insulation, non-woven wrapping, tinned copper braiding and a polyurethane jacketing. The cable optionally contains either one or two control pairs.


The new cable supports accelerations in excess of 5g and travel speeds up to 5 m/sec. Travel distances can range up to 100 m. Intended for flexible applications, it has a minimum bend radius of 7.5 x OD.

Other than its outstanding ability to withstand high accelerations, FD 796 CP behaves much like any other high-performance servo cable. It resists oil and flame to UL standards. Temperature range for flexible applications is –40 to 80ºC.


Download out latest whitepaper if you’d like to learn more the cable design challenges that result from high accelerations

Networking - How the digital Revolution is also changing production

The fact that data needs to be transmitted quickly has long been accepted, even in the tough world of industrial production. Camera-supported quality checks for moving applications with especially high requirements for data transmission, with a CAT.6A Ethernet cable, the Lapp Group have developed for the first time a cabling solution that is highly flexible and can withstand the high stresses in production.



Until then, the market could provide choice but not the solution. Either a rigid or flexible cable with the Cat.6A parameters, or a highly flexible cable which could only manage a maximum transmission rate of up to 1 Gbit/s.





 

With the introduction of the ETHERLINE® Cat.6A, the customer now gets the best of both worlds; high data transmission rates of up to 10 Gbit/s , whilst being suitable for moving applications such as in power chains. This was possible thanks to innovative material selection and wrapping technique, but the idea came from two of Lapp's youngest talents.


Download the latest issue of CableWorld for the full story

Robotics - Triumph of Artificial Intelligence

Robotics is the supreme discipline for cables
 
As demanding as the tasks performed by robots are, the requirements for the cabling are
equally stringent. That is why the issue of robotics is a major focus in the Lapp Group. Building
on a wealth of manufacturing expertise within the company, while the French subsidiary Lapp
Muller in Grimaud has specialists with more than 25 years' experience in robot and drag chain
applications.

This know-how creates competence. Ultimately, competence is exactly what it takes to be
successful in robotics, with its countless range of applications and individual designs. It is an
area where practically no two applications are the same. This means that every cable solution
also has to be unique, whether it is to provide a specific power supply for robots or high-performance
data transmission, for example when building robots with high resolution camera
systems.


However, for many robot applications the outer material of a cable is just as crucial as what
is inside. The cable may need to be able to withstand mechanical abrasion and chemicals,
or requirements might include resistance to harsh working environments, or extreme tensile
strength. Whatever people demand from a robot as an indefatigable worker, they demand
exactly the same from the cables.




Download the latest issue of CableWorld for the full story

Tips for Designing Cable Carriers

Of all the machine design details to worry about, cable carriers probably don’t top your list. Yet if you care about the reliability and uptime of moving machines, it pays to devote extra engineering attention to the carriers and the components within them.

A well-designed cable carrier will dramatically extend the life of cables and fluid power supply lines by protecting them from damaging bends, crimping, abrasive wear and crushing.

Unfortunately, some cable carriers are poorly-designed and can trigger the very same cable and supply line failures they were supposed to prevent, causing expensive machine downtime. The potential for failures can largely be avoided by following a collection of simple carrier design guidelines developed by our Systems Group.

Over the years, our engineers have designed, built and delivered thousands of populated cable carriers that have been implemented in a wide variety of servo and VFD applications on packaging, automotive and other industrial machines.

Here are some basic tips for designing populated carriers:

•         Calculate. Determine the minimum bend radius and clearances of all the components that will fill the carrier. Define the optimal carrier length and location of the fixed mounting points.

•         Weigh. Distribute the weight of the fill components within the carrier. Take the time to calculate the weights of individual components, and place the heaviest components on the outside of the carrier.

•         Influence. Consider the operating environment. Chemical exposures and thermal conditions can influence the design of cable carriers.

•         Divide. Split the carrier into separate cavities so the cables and hose can all move independently of one another.

•         Get Help. Involve your cable and carrier vendors in the design process. They work with carriers every day and can offer additional engineering expertise that will help you design a carrier that will go the distance.

For detailed engineering guidelines, download our technical paper on cable carrier design.

Protecting Cables From Oil Damage

Of all the chemical exposures that can affect the life and performance of electrical cables, oil is one of the most damaging. Used as a coolant and lubricant in many industrial and infrastructure settings, oil can inflict molecular damage on the polymers used for cable insulation.

Degradation Happens. When insulation polymers are exposed to oil over time, two degradation mechanisms can occur. Some polymer formulations will absorb the oil, causing the polymer to swell and soften. A loss of tensile properties results. Other polymers will lose their plasticizers when exposed to oil, causing a loss of flexibility and elongation.

Either way, oil exposure renders many polymer compounds ineffective as insulators. This attack on polymer properties can result in downtime, costly repairs and, in the worst case, hazardous electrical conditions.

Temperature extremes and other chemical exposures can exacerbate the damage caused by oils. The greater the intensity of the oil exposure and the operating temperatures, the faster oil will degrade insulating polymers.

Lasting Damage. Once it gets underway, oil damage is not reversible. But it can be prevented by selecting cables with inherent oil resistance.

Without a deep knowledge of the specific polymer compounds used in the cable you’re considering, it can be difficult to know which products can stand up to oils and for how long. Making matters worse, individual polymer formulations may not offer equivalent performance even if they have the same family name. Not all PVCs are created equal, for instance.

And that’s why testing is so important. To avoid oil resistance problems, engineers should pay close attention to UL tests, which help determine how a cable will react in the industrial oil environment.

 

Made in Germany

Jürgen Sielaff, U.I. Lapp GmbH

Highly specialized production with the best levels of quality assurance - this continues to be a unique feature of German industry. The new metal processing center for industrial connectors operated by the Stuttgart-based Lapp Group shows that the industrial production of components can be performed at the highest level, even in the age of globalization and internal competition.

Fully automated, reliable and made in Germany.

 

The Stuttgart-based Lapp Group boasts one of the most modern plants in Europe for the mechanical processing of rectangular industrial connectors, having operated its new metal processing center since mid-2013. Four handling robots, two independent metal processing centers, a washing center and a fully automatic riveting station with a loading and unloading station work around the clock to produce around 580 industrial variants of the EPIC ^® rectangular and circular connectors from 54 unfurnished housings. The new production facility not only achieves greater throughput, it can also manufacture all variants in the product range in a flexible manner with short lead times. The state-of-the-art plant was supplied and manufactured by German-based CHIRON Werke GmbH.

The contact inserts of the rectangular connectors have been manufactured in Germany for some time. This process was previously performed manually, but was now automated and integrated into production so as to reduce delivery times. This has resulted in highly automated production with a very high and consistent level of quality. The process data is subject to continuous digital monitoring – without any added costs. One of the additional aims of this process integration was to enable new product variants to flow flexibly into the processes and to engage in continuous adaptation of the product range in line with the new requirements.

Highest levels of repeat accuracy

Although quality control of the EPIC ^® connectors was previously performed manually, the entire process will now be performed fully automatically. The robots use a measuring button to measure each individual part and calculate any deviation and tolerance. They then immediately offset the deviation and search for the zero point of the hole or identify parts in which the tolerance deviation is too high, enabling the production facility to achieve a very high level of repeat accuracy.

The focus then moves to the riveting station, another area featuring fully automated processes. The bolt is individually moved, positioned and riveted in accordance with the type and position. The riveting point is corrected automatically as required. The riveting pressure is also monitored, with the values being documented and stored. This provides assurance for the operators that each part has been riveted. Conversely, in the case of manual production, this can only be observed by the operators once production is output by the machine. The advantages are obvious: the plant does not output any parts that have been processed incorrectly and traceability is assured at all times.

Milling instead of cutting

A unique feature of the Lapp metal processing center is thread manufacturing with the help of thread milling cutters – a system that was developed in-house. As special aluminum coatings with outstanding hardness are used for the EPIC ^® housing in order to make it suitable for application in all kinds of environments, this results in a fivefold to tenfold reduction in the service life of standard drilling and threading tools. However, thread milling cutters sustain virtually no measurable wear and provide a range of additional advantages.

The thread milling cutters enable spindle rotation speeds of up to 20,000 rpm to be achieved. After processing, it is as though the thread has been polished – no cleaning is required. The dimensional accuracy of the CHIRON precision processing centers is in the m range. In addition, various core hole and thread diameters with an identical gradient can be manufactured using only one tool. A further advantage of PCD cutting, in which polycrystalline diamond is used as a cutting material, is the low level of component heating. Due to the quick processing, there is less of an increase in the work piece temperature. This is more cost-effective as it enables operation with minimum quantities of cooling lubricant. In this case, however, the components are virtually warm to the touch upon exiting the device.

With the help of the circular bore thread milling cutters and the

undercuts that can be generated with them following the thread output, thread depths are achieved in virtually the same way as with through-hole threads. As a result, the rectangular connectors are compatible with conventional cable glands. The fact that there are no longer any burrs in the thread outlet means that deburring does not need to be performed. By implementing the thread milling cutter in the new metal processing center, we were able to further increase the service life of the tool.

New machinery concept

The aim of the new machinery concept was to not leave anything to chance and to turn weaknesses into strengths. "The combination of full automation and digitised quality control enables the machine to attain a high level of repeat accuracy and quality," enthuses Jürgen Sielaff, Production Manager for mechanical processing at Lapp.

The biggest challenge was to ensure that all the different variants of the EPIC ^® rectangular and circular connectors could be produced using a single machinery unit. The adjustment of the various product variants using the zero point calculator was a very complex procedure, but CHIRON was ultimately able to create a basic device with the ability to accommodate all 54 connector variants. "In succeeding in accommodating dozens of product variants across a very broad range at a principal tension, we have created an incredibly flexible production facility," explains Kristoffer Siegmann, Project Manager at CHIRON.

This means that the CHIRON production facility is also equipped for future demands, not least thanks to the integrated cleaning device that exceeds current requirements.

Control is now performed by a central computer with an SAP connection that enables it to immediately convert each customer order into a workshop order. In the event of a complaint, every employee can instantly access all quality assurance data.

Staying competitive through innovation

The example described here is a highly modern production plant that, thanks to the combination of numerous innovations, an elaborate machinery concept, fully automated production and highly qualified and highly trained personnel, achieves the highest level of quality without generating costs any higher than those involved in production in low-wage countries. This means that the "made in Germany" manufacturing process remains competitive whilst guaranteeing the highest levels of quality and dimensional accuracy.