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The work came to Alken after 10 other subcontractors had withdrawn from the contract due to the difficulty in machining these parts.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

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

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

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

Jointmedica Ltd, based in Worcestershire, produces Class 3 implants in the orthopaedic sector and has, in its product portfolio, an innovative mobile bearing knee replacement, as well as development activities relating to hip resurfacing and the manufacture of custom-made devices for specific patients created directly from CT scans.

High-level development activities can now be undertaken in-house at Jointmedica’s facility in Hallow, utilising Alphacam software. As well as allowing the company to take advantage of the intellectual property available via the company’s founder, Professor Derek McMinn, Alphacam assists the design team to further explore these innovative new designs and incorporate new materials, driving the advancement of orthopaedic hip and knee replacement surgery. As a result, exacting controls and the highest quality, are paramount.

Technical director Roger Ashton says: “If we consider the hip resurfacing market in isolation, several years after the procedure began, a small number of patients suffered physiological problems due to hypersensitivity to various metals. The end result was that a small percentage had bearing-related failures. This led to a sharp decline in the use of metal-on-metal articulations in the resurfacing context. It is Jointmedica’s purpose to work with alternative bearing materials, such as ultra-high molecular weight polyethylene, using the successful resurfacing methodology to generate a product that will re-establish the hip resurfacing market. In terms of our surgeon team, we are privileged in being associated with the most experienced hip resurfacing designers and surgical innovators in the world.”
When the company brought its manufacturing research and development in-house, the need for investing in a suitable machine and CADCAM software became apparent.
Ashton says: “It was clear we were going to have an interesting combination of 2D turned profiles and surface machining with milling, drilling and slotting, and we were conscious that we had a lot of complex geometries with which to contend. As a result, we needed a CNC machine tool and software that could manage all of our milling and turning requirements, including in sometimes more than three axes.”
He says that the company’s Brother Speedio M140x2 five-axis CNC machining centre fit the bill perfectly: “Many products require a combination of three-axis and four-axis machining, plus turning operations, so Alphacam will always be an integral part of our manufacturing process from now on.”
Generating custom implants at Jointmedica begins the moment the patient’s CT scan is received, which allows the company to start modelling the bespoke product. Jointmedica uses two CAD systems to design the solid models, mainly Creo and, occasionally, SolidWorks. The files are usually sent in XT, STEP or DXF format for the turning cycle in the lathe software.

Jointmedica uses Alphacam Ultimate Mill and Standard Lathe to machine the finished product, with the Brother machining centre capable of performing both turning and milling operations.
Oliver Clayton, manufacturing engineer at Jointmedica, says: “I take Alphacam’s 3+2 system and incorporate it into some of the bespoke custom devices, and then an easier three-axis and turning program definition on the cutting paths for a simpler, axisymmetric product. In the turning program I mainly use the CAD side in drawing the geometry and applying the tool path. That’s extremely useful because I can incorporate not only the model, but draw my own tool paths in there with the geometry.”
As an example, the materials for a ball and socket type bearing, which work well when implanted in the body as a hip replacement, can include ultra-high molecular weight polyethylene of differing formulas, and a counter face of cobalt chrome, ceramic or other material.
“Through accurate machining driven by Alphacam, material wastage is kept to a minimum, and we can also ensure the final, bespoke product is suitable for the patient,” says Clayton, who adds that it is of utmost importance that the implants are of the highest precision.
“When we come to CMM measurements they must be dimensionally correct, and Alphacam ensures we get the right results every time. When considering our prototyping expectations, we are comfortably achieving the industry standard tolerances, and a bearing surface finish of 0.8 Ra for one-offs. We know that future production capability will significantly exceed these figures, and we’re confident in the solution afforded by the Brother CNC driven by Alphacam.
“Due to Alphacam’s accuracy, I can be totally confident that the software guarantees the product will be right first time, every time,” he continues.
For Jointmedica, a particular challenge facing the manufacturing process was manipulating the tool path to get the quickest machining time for a particular component. Here, Alphacam’s ability to define the best cutting tools and tool paths allows these to be manipulated to set the quickest timescale with the best path for the device to be manufactured accurately.

Clayton concludes: “When I refer to accuracy, I don’t just mean the speed and accuracy of a geometric tool path I put over a CAD model that’s come into Alphacam; I mean combining a number of different types of operations – the accuracy and ease of Alphacam coming in and picking up at a point that I’ve designated on the software, at a later stage on the product with an alternative type of machining method. It picks up accurately, as verified with our CMM equipment, and it is always within the specified critical dimensions. This is a huge benefit.”
For further information www.alphacam.com