Making light work of lights-out milling

UK manufacturing lags behind the productivity performance of fellow G7 members and that of other major global economies. A lack of investment and shortage of skilled staff are widely considered to be major contributing factors to this lamentable situation. In addition to being regarded as an effective means of UK manufacturers achieving productivity improvements, the implementation of advanced automation technologies invariably helps solve skills shortages.

Hertford-based Qualiturn Products is a prime example of a forward-thinking business that has achieved world-class levels of productivity by embracing the use of automation systems and developing efficient new working practices.
Established in 1974, and now run by second-generation managing director, Nick Groom, Qualiturn Products says it has grown to become one of the UK’s leading suppliers of precision mill-turned components. In 1990, the company became one of the first subcontractors to operate its mill-turn machines in a ‘lights-out’ manner. The use of barfeed systems and other advanced production aids means that since that time, the business has operated 24 hours a day, seven days a week, 365 days a year, with only daytime staffing.
Prompted by the success of Qualiturn Products’ 24-7 production of precision turned components, in 2014 the company established Qualimill, a subcontract milling division that embraces similar, highly efficient, lights-out operating methods. Just as the application of innovative technologies facilitated a lights-out mill-turn manufacturing regime, the implementation of advanced automation aids, such as the Lang Robo-Trex system, supplied by Thame Workholding, has enabled Qualimill to operate milling machines ‘lights-out’, and helped the division to become a successful subcontract manufacturer of milled components.
To satisfy the rising demand for Qualimill’s services, the company recently moved into much larger premises and installed several additional production aids, the most recent of which is a second Robo-Trex robot automation system. The productivity gains made possible by the use of Qualimill’s first Lang Robo-Trex robot systems was a major factor in the decision to purchase the second system that now feeds a Doosan DVF 5000 machining centre.

Qualimill’s two Lang Robo-Trex robot systems each use two trollies that act as mobile storage mediums. These trollies are loaded with multiple vices that hold workpieces which are ready to be loaded into the machine by the systems’ robots. The robots pick workpieces from the trollies, load them into the machine tools and, when they are fully machined, return them to the trollies. When filled with machined parts, each trolley is removed, and a replacement loaded with multiple workpieces ready to be machined is added.
Working unattended and fed by the Lang Robo-Trex systems, the company’s machining centres run throughout the day. Before the end of each manned shift, the Robo-Trex trollies are replenished with full consignments of workpieces, enabling each machining centre to run unmanned through the night.
Robo-Trex trollies are available in two sizes, the smaller version has a capacity of 30 vices to accommodate parts up to 120 x 120 x 100 mm, while the second, larger model has a capacity of 42 vices for parts up to 120 x 100 x 70 mm. The Robo-Trex system is able to handle four automation trolleys. Therefore, depending on part size, the available storage capacity increases to 120/168 vices.
The patented, edgewise mounting of the system’s vices ensures maximum space utilisation, while accessibility to the clamping devices allows workpieces to be exchanged, without removing the vice.
An intuitive, easy-to-operate touch panel enables straightforward control of the automated system and, as external access to the trolley is possible, production remains seamless because machining cycles do not need to be interrupted. Control of the zero-point clamping system can be performed either pneumatically through the machine tool, or mechanically via the system’s robot.
“Increasing demand from our mill-turn customers motivated the launch of our Qualimill division,” says Groom. “To ensure that we were able to replicate the success of our Qualiturn operation, when setting-up the new division we put into operation advanced automation systems – where possible – and applied similar efficient working practices to those used in our mill-turn operations.
“Soon after the formation of Qualimill, in an effort to gain maximum milling efficiencies, we looked for an advanced technology that would allow lights-out running of an existing CNC milling machine,” he adds. “We found the answer in the Lang Robo-Trex automation system from Thame Workholding. Having been impressed by the performance of our fist Lang Robo-Trex robot system, to help satisfy ever rising requests for our milling work, we recently purchased a second system.
“Our decision to launch Qualimill and employ highly-efficient production technologies has been validated by the division’s success. Our new Lang Robo-Trex automation system now feeds a recently purchased Doosan DVF 5000 machining centre and further extends our lights-out production capabilities.

“By releasing the full, latent productive potential of the machine tools they serve, our two automatic handling systems release skilled staff for more technicality demanding work. In addition, our Lang Robo-Trex automation systems are helping us to accelerate production throughput and reduce our lead times. They also enable the generation of cost-effective quotes and help us to attract further business.”
Thame Workholding’s sales manager Gareth Barnett adds: “As well as providing industry with a range of cost-effective, standard work-holding systems from several of the world’s leading manufacturers, we also design and manufacture bespoke solutions in-house. Our experience and expertise in all aspects of work holding allows our staff to fully understand customer needs, then to provide optimum, cost-effective solutions.
“Our grasp of Qualimill’s brief, relating to the division’s quest for efficient lights-out working, enabled us to recommend the Robo-Trex automatic handling system with confidence,” he adds. “Now that the company’s first system has delivered on all of the promises we made, we were delighted to receive an order for a second system.”
For further information www.thameworkholding.com

XYZ LR machines prove convincing at Alken

Alken Engineering is a long-term user of XYZ Machine Tools’ ProtoTRAK mills, being an early adopter when the ProtoTRAK control was introduced to the UK in 1993. The company now has 10 XYZ ProtoTRAK mills and three XYZ ProTURN lathes on its capacity list, but for many years resisted purchasing any XYZ ‘full CNC’ machines; until now.

Alken Engineering, part of the four-company Alken Holdings Group, is a specialist machining and fabrication company that counts many blue-chip companies, such as Bentley Motors and Volvo, as customers, as well as working in the aerospace, power generation and general subcontract sectors. While the majority of its work involves the machining of steel and more exotic materials, Alken also gets involved in components manufactured from aluminium and nylon, and this work led to the purchase of its first XYZ LR (linear rail) machining centre.
“Even though the ProtoTRAK mills and lathes had provided flawless service, I hadn’t considered XYZ machining centres as I didn’t believe they could compete quality-wise,” says Paul Coverley, managing director. “However, when I had a demo of the new LR machines and the Siemens ShopMill control, my eyes were opened.
“In addition to the capability of the machines, the ShopMill control appealed as we get involved in machining from one-off to batch production, and the Siemens control is perfect for that,” he adds. “And, while I still needed to be persuaded about the full potential of the XYZ LR machines for heavier machining work, that would soon change.”
That persuasion came about when the Alken Group won a contract to machine a series of connector blocks which would be used in the construction of a bridge linking the mainland to Tintagel Castle, the fabled birthplace of King Arthur. These connectors are machined from solid blocks of Duplex stainless steel, with the finished parts measuring up to 460 x 237 x 237 mm, with slots that are 135 mm deep in places.

The work came to Alken after 10 other subcontractors had withdrawn from the contract due to the difficulty in machining these parts. As a result, Alken was faced with a tight deadline, as well as a capacity issue.
“We knew that any delay would put the bridge project back, which was unacceptable to the main contractor, American Bridge, and its customer, English Heritage,” explains Coverley. “However, our initial concern was that the parts could have been described as ‘un-machineable’. Following discussions with our customer, Underhill Engineering, changes were made to the design. Once those issues
were overcome, we were then faced with machining Duplex, including those slots.”
Initially, machining was carried out by two other companies within the Alken Group on what Coverley describes as ‘high-end’ machining centres: “These companies had what I thought was the experience and equipment to handle the work, but we found ourselves falling behind schedule as the machines struggled with the volume and complexity of the parts, so we had to bring work into Alken Engineering. The only capacity we had available was on our XYZ LR 500, 750 and 1000 machining centres. At this point there was still doubt in our mind that the XYZ LR VMC machines had the capability to handle materials such as Duplex, even though XYZ were telling us otherwise.”
With each of the connector blocks requiring between 70 and 80 hours of machining, there was a lot at stake, and Alken, along with assistance from XYZ Machine Tools and the tooling supplier, began to test the capability boundaries of the LR machines.
To produce the slots, the tooling involved an overhang of 4xD using an indexable insert cutter with 12 mm button inserts running at 140 m/min cutting speed and 0.3 mm/rev feed rate. Considering the material being cut, both the machines and tooling produced the quality and finish required.
“Once we got our collective heads around the machining of Duplex we haven’t looked back, and the XYZ LR machining centres are producing these parts better and quicker than those high-end machines we started with,” says Coverley. “As a result, we’ve got the project back on schedule and any doubts that I had about the capability of XYZ machining centres have disappeared. I’ve nothing but praise for the capability of these machines and the Siemens control.”

The XYZ LR range was introduced in 2017 and was the first full series of machining centres equipped with linear rail technology. XYZ had held off developing a linear rail machine as it did not believe that early systems were robust enough to meet its stringent quality standards. However, recent significant developments in linear rail technology saw these concerns eliminated and, as the example at Alken proves, these are highly capable machines with the ability to remove high volumes of material, even challenging metals such as Duplex stainless steel.
There are three machines in the LR range, these being the XYZ 500 LR, XYZ 750 LR and XYZ 1000 LR, with the number equating to the X-axis travel. All machines feature an 8000 rpm/13 kW spindle; 20 m/min traverse rates; and a 12-position carousel-type tool changer on the smallest machine, with a 20-position carousel (24 position arm-type optional) on the two larger variants. Also included in the XYZ range are the heavier duty, more powerful, HD VMCs. The XYZ 660 HD, XYZ 800HD and XYZ 1100 HD have boxway slides and are available with a Siemens or Heidenhain control.
For further information www.xyzmachinetools.com

Getting a ‘Gripple’ on green maintenance

Sheffield is renowned for the way it has shaped British industry over the past 300 years. While the mines and foundries may no longer be the driving economic force they once were, one manufacturer – Gripple – has set-up shop in the city and generated a fixings empire reaching as far as Australia.

Gripple was founded by former wire salesman, Hugh Facey, in the 1980s after discussing the woes of connecting fencing with a frustrated farmer on a Welsh hillside. Setting his mind to finding an easier, safer and more efficient way of joining two wires together, the concept for the first Gripple wire fastener was born.
Fast forward 30 years and Gripple now has three sites in Sheffield, and sells products to agriculture, viticulture and construction markets around
the world.
“We’ve now manufactured over 500 million Gripple fasteners, all using production equipment we have designed and manufactured ourselves in house,” begins Tim Barker, engineering site leader for Gripple’s Old West Gun Works site. “This is no mean feat, and to keep pace with demand, we employ a robust planned maintenance strategy for all of our production equipment, to ensure it is able to maintain its maximum operational capacity.”

Parts washing forms a fundamental part of the company’s maintenance plans. Yet, up until four years ago, like many manufacturers and machine shops up and down the country, Barker and his team relied on hydrocarbon-based solvents and aerosol cans to clean and degrease the parts. This meant the team was exposed to some quite harmful cleaning products, simply because that was the only real way of getting the job done.
“Sustainability is a massive part of the Gripple ethos, and where possible we look to keep our impact on the environment to an absolute minimum,” says Barker. “For example, one of our sites is located next to the River Don, which has undergone massive ecological regeneration in recent years. It used to be a dead river 25 years ago, but now there are guys fly-fishing there; the kingfishers are back and it’s an abundance of life, and that’s how it should stay. As such, we have to be extremely careful when it comes to waste removal, and it was one of the key drivers for revaluating our parts washing processes four years ago.”
With a view to eliminating any potentially environmentally-harmful chemicals from its parts washing processes, Barker and the Gripple team turned to Safe Solvents in 2015. Following an initial trial of the company’s Typhoon parts-washing system, he quickly realised the huge impact it could have; not only in improving the company’s environmental credentials, but in eliminating maintenance technicians’ exposure to the health and safety risks often associated with hydrocarbon-based cleaning solvents.

“When we first brought Safe Solvents in, I so impressed by the system – how easy it was to operate, and how switched-on the guys were – that I immediately rolled it out across the other sites,” says Barker. “The Typhoon system means all parts washing is done in a controlled, safe and environmentally-friendly way, rather than just sticking parts in a bowl or sink and using aerosol-propelled solvents.”
The Typhoon system is a modern take on an old sink-on-drum manual parts-washing machine. It provides a trio of cleaning options: tap, flow-through cleaning brush, and soaking tank, as well as trays and working areas to scrub or soak both small and large components. What really sets the offering apart from other solutions however, is the cleaning fluid.
Safe Solvent’s Advanced Parts Wash Fluid (APWF) is a water-based degreaser for general parts. Comparable with standard hydrocarbon-based solvents, it gets to work quickly on cutting through grime and includes a built-in rust inhibitor which acts as a protective barrier for most metals. Crucially, the degreaser works at ambient temperature, meaning there is no need to heat the fluid during the wash process; and it is both non-flammable and non-carcinogenic.
Says Barker: “Compared to the traditional methods we used in the past, making the switch to a modern, greener and safer cleaning solution was a no-brainer. You really can’t compare the cost, there’s a massive saving compared with aerosol-based solvents. Also, the health and safety impact is huge. In the past, all the propellants we used came with a huge stack of COSHH listings, whereas the Typhoon system is the polar opposite.
“The rust inhibitors are great from a maintenance perspective, too,” he continues. “They help prevent oxidisation forming on the surface of materials, as if a part is not fully clean it can be quite difficult to spot a surface defect or fault which could in turn impact production once that part is refitted within a machine.”
As well as helping to de-risk Gripple’s maintenance programmes, up to 80% of Safe Solvent’s cleaning fluid can be recycled as a traffic film remover.

“Once we’ve used the fluid and it’s been recycled, any excess is offered to the team to be used as a cleaning product for their own garages at home,” explains Barker. “It’s great for cleaning car alloys. From my perspective, it’s fantastic to be able to recycle the fluid, but I’m also confident in the knowledge that I’m not sending anything out there that is harmful to the environment.”
He concludes: “Ultimately, making the switch to Safe Solvents’ parts-washing system has been a huge tick in our environmental box. I know that any fluid spillages are safe and will do no damage to our employees or the environment. They’re a company I want to grow with us, so that when we introduce new ways of manufacturing parts, they can help us do so in a safer, easier and ultimately better way.”
For further information www.safesolvents.co.uk

Sawing nickel alloys three times faster

A specialist stockholder serving the oil and gas industry, Howat Group, perhaps better known by its trading names AMS, ESS and Ancon, has installed a 14th Kasto bandsaw – a KASTOwin pro AC 5.6 – at its new centre in Barnsley, which opened at the end of 2018. The facility represents an investment of more than £2m by owner Malcolm Howat, and has been timed to coincide with the oil and gas sector’s nascent emergence from a downturn that started in 2014.

Half of the sum went on acquiring a freehold, 60,000 sq m property on Cortonwood Drive in the Dearne Valley area of Barnsley. The remainder was spent on infrastructure, materials handling equipment, two further Kasto bandsaws and refurbishment of all the older models, some of which have been in service since the 1990s and still cut accurately.
The German-built KASTOwin pro, supplied ex-stock from the manufacturer’s UK subsidiary in Milton Keynes, is a competitively priced machine designed for cutting tough nickel, titanium and stainless steel alloys up to 560 mm in diameter using a tungsten carbide-tipped (TCT) blade. However, the machine also allows economical cutting of low-alloy steels when the blade is swapped for a high speed steel (HSS) bi-metal type.
Howat’s operations director Emma Parkinson says: “We have four dedicated carbide cutting bandsaws on site which include KASTOtec AC5s and now the KASTOwin pro, which is even more capable. They are ideal for cutting our Inconel 625, 718, 725, 825, 925 and K500 stock. Our latest investment was to increase our overall cutting capacity but also to improve efficiencies around nickel alloy cutting specifically. The remainder of our sawing machines with capacities up to 800 mm diameter are intended for bi-metal cutting, but can also use TCT blades with offset teeth.”
She adds: “The advantage of the latest KASTOwin pro saw, apart from its ability to use either type of blade economically, is its high productivity, which is down to fast cutting speeds and quick set-up using the new touchscreen control.”

Programming is fast with the Kasto EasyControl, as cutting parameters for any given material, size and cross section are determined automatically by a built-in database, so all that is needed is to enter the cut length and number of pieces required, and press start.
The productivity benefit is most pronounced when cutting nickel alloys. Formerly, the company was sawing Inconel 718 with a TCT blade at 3 to 4 cm2 per minute, but on the KASTOwin pro that has risen to an average of 12 cm2 per minute. So, for example, a 200 mm diameter bar that would previously have taken up to 90 minutes to cut can now be processed in less than half an hour.
Parkinson explains that she was familiar with the benefits of the latest German-built bandsaws compared with the performance of the legacy machines, having worked with this make of saw when previously employed at another stockholding company.

So when Howat Group, one of the largest stockholders in the UK, needed more capacity to cope with an increasing number of high volume orders for nickel alloy billet and low-alloy steels, the KASTOwin pro was a logical choice. The large batch sizes frequently ordered make it economical to spend time changing from an expensive TCT blade to bi-metal, to extend the life of the TCT teeth.
A feature of the automatic KASTOwin pro is its electro-mechanical down-feed via two ballscrews, each with a servo drive for precise, infinitely variable control. The positive motion allows smaller tolerances to be set, typically -0 / +0.5 mm for most stock, minimising material wastage. There is a retraction unit for separating the blade from the material to protect the cut surface when the saw head moves back, which also helps to minimise tool wear.
The band is driven by an 11 kW motor, delivering infinitely adjustable cutting speeds from 12 to 150 m/min, and providing plenty of capacity for TCT sawing. Helping to dampen vibration and lower noise during operation are ‘Trum’ guides mounted at the return side of the blade, inside the top of the saw head guarding. These guides suppress vibration on the side opposite from the cutting action, prolonging blade life and promoting high squareness accuracy and good surface finish.
Partly due to larger orders being received, and because of the high value of nickel-based metals, Howat Group’s monthly turnover trebled within a few months of the stockholder opening its new facility. Key to maintaining growth is providing customers with a high quality service in terms of prompt delivery of material that is within tolerance.

Parkinson concludes: “It is for this reason that we have more or less standardised on Kasto sawing equipment and see the supplier as a partner to our business. We regard the manufacturer as a premium brand whose rigid and technologically advanced bandsaws maximise blade life and cut accurately for decades, despite heavy use.”
For further information www.kasto.com

Low-deformation clamping and fast set-up

Clamping devices have a significant influence on precision and cost-effectiveness when undertaking the manufacture of gearbox components. For maximum flexibility and efficiency in production, Rollstar AG has invested in a large, six-jaw pendulum compensation chuck with a quick-change jaw system and rapid adjustment mechanism. According to Schunk, the solution minimises set-up times and delivers results faster and more economically than conventional clamping solutions.

The Schunk Rota NCR 1250 six-jaw pendulum compensation chuck, which Egliswil, Switzerland-based Rollstar uses to manufacture gears on a Pittler PV 1600 vertical turn-mill centre, is a large-dimensioned chuck with novel features.
Was it a worthwhile investment? “Definitely,” says Christian Märki, purchasing manager and member of the extended management team at Rollstar. “Due to the machine design, including the clamping devices, we were able to reduce set-up times by half while decreasing the reject rate by 75%.”
The investment pays off especially for thin-walled components and high-quality materials. Here, the company’s aim was to achieve the necessary quality levels, reduce throughput times and lower the overall costs of producing deformation-sensitive parts in two operations, while ensuring process reliability.
Thanks to the Schunk Rota NCR, parts that were previously manufactured on another machine in a three-jaw chuck with a two-pressure clamping system are now being produced faster, more precisely, and with greater process reliability.

“In the past, when we clamped a ring gear, or a ring with a finished diameter of 820 mm, in a three-jaw chuck, the circularity or cross-sectional tolerance was higher than 0.1 mm,” explains Märki. “However, if we clamp the same component in the Rota NCR, we achieve cross-sectional tolerances of 0.02 to 0.03 mm. This precision increases the service life of our gearboxes even further because the rolling bearings are subjected to completely uniform loads.”
The upshot is that the gearboxes can be used much longer without any maintenance works, and sudden failures are extremely unlikely. Rollstar gearboxes are valued for their extreme reliability in tunelling and mining applications, where unplanned downtime is very costly.
The clamping concept has been developed in close co-operation between Rollstar, Pittler and Schunk lathe chuck specialists, whereby the necessary range of components, design requirements, and set-up times were systematically taken into account. According to Rollstar, the decisive factor in choosing Schunk was the combination of six-jaw chuck, quick-change jaw system, rapid jaw adjustment and Schunk’s ability to deliver quickly. Finally, the testimonials of other clients, which Rollstar visited, helped seal the deal.
The Schunk Rota NCR six-jaw pendulum compensation chuck consists of a central chuck piston carrying three inner pendulums aligned at 120°. Each pendulum is connected to two base jaws. This configuration ensures workpiece centring between six contact points, adjusted in pairs. As the clamping forces are directed towards the chuck centre, optimum centring is achieved without distortion of the workpiece. The chuck adjusts to the workpiece with its oscillating jaws.
Standard jaws can be used to replace elaborate system jaws and special solutions on the Rota NCR jaw interface, which saves time, cost-intensive special mechanisms, and reduces set-up costs. An integrated quick-change jaw system minimises set-up times on the idle machine.
“We use two sets of base jaws and set up the top jaws outside the machine; in other words, while machining is still in progress,” explains team leader Daniel Fierz. “The set-up process for the second operation then takes only 20 minutes, including cleaning.”
Here, the base jaws are pushed open, before they automatically lock in place and are secured with a quarter-turn of the torque wrench. Due to the quick jaw adjustment, the base jaw position can be adjusted easily in just a few simple steps.
“The quick adjustment feature allows me to set the clamping range in defined steps,” explains machine operator Willy Ummel. “The system works flawlessly and is easy to clean.”
In the past, up to two hours of machine downtime were required for a conventional set-up process of such workpiece sizes. Now it takes Ummel less than 30 minutes. Top jaw sets with hard chuck jaws and claw inserts are available for raw part clamping, and sets of soft top jaws are already bored in the different diameters for machining the part from the other side.
One of the main goals of the investment was for the machine to run as smoothly as possible with only minimum interruptions,” says Fierz. “The lathe chuck is so precise that we can use jaws again and again without re-boring. After exchanging the jaws, we achieve a run-out of 0.02 mm without any additional adjustment.”

The vertical position of the spindle also plays a role here. Maximum freedom of movement and, therefore, optimum centring, are assured because the components are put on to surface-ground pillars and not on the chuck jaws, as is the case with horizontal spindles.
“The vertical machine allows for significantly better oscillation than machines with a horizontal spindle, where the friction between the component and the jaws restricts the pendulum effect,” emphasises Fierz.
When finish-machining or clamping rough-turned surfaces, Ummel can clamp the Rota NCR’s pendulum in the centre position so that all six jaws move concentrically. Use of the lathe chuck has had a welcome side effect: the reject rate has fallen by around 75% since implementation. This reduction is due to dramatically less deformation, the high precision of the jaw change process and the improved flat work surface of workpieces. The reduced reject rate results in considerable savings, especially with high-quality materials such as the ferritic castings frequently used by Rollstar.
According to Märki, a decisive advantage of the clamping solution is the flexibility that Rollstar has gained in production: “Even though we typically manufacture in batches of 10, we can now squeeze in rush orders at any time without losing efficiency.”
This flexibility has allowed the company to reduce stock levels without compromising its service level. In the near future, Rollstar plans to use the chuck for machining components with diameters between 400 and 1600 mm.
“It’s easy to clean, a breeze to adjust and extremely easy to load thanks to its horizontal position,” concludes Märki.
For further information www.schunk.com