Workholding precision boosts Michell Bearings

As the inventor of the hydrodynamic bearing more than 100 years ago, Michell Bearings has spent the last century constantly developing its product range to meet the ever-changing needs of the company’s global customer base. The use of the latest production technology, decades of in-depth experience and the application of stringent quality systems, has resulted in the South Shields-based company gaining an impressive reputation in bearing design and manufacture for both the industrial and marine engineering sectors.

As the efficiency, reliability and longevity of any bearing depends largely on the quality of the methods used in its manufacture, Michell Bearings employs a wide range of CNC machine tools and advanced production aids.
The recent installation of a Hermle C60 UMT five-axis CNC machining centre prompted Chris Kemp, Michell Bearings’ manufacturing engineering manager to contact Tony Lewis of Thame Workholding with the intention of exploring ideas that would enable the company’s new acquisition to maximise its potential.
“As a designer and manufacturer of self-contained white-metal bearings and PTFE-faced hydrodynamic bearings, our products can be found in a range of challenging applications throughout the world,” states Kemp. “We have a long history of manufacturing bearings that withstand the test of time, and have products installed with 35 of the world’s navies on more than 300 vessels. Meticulous production and inspection methods ensure the quality of our bearings and help safeguard the global standing of the company.
“In accordance with our ongoing quest to enhance the company’s capabilities and further increase production efficiencies, we recently purchased a Hermle C60 UMT five-axis CNC machining centre with a capacity of 1200 x 1300 x 900 mm in the X, Y and Z axes. Our new machine tool allows the dynamic processing of workpieces up to 2000 kg in weight.”
With the aim of achieving the highest possible yield and looking to guarantee that the machine consistently met the demanding standards of precision at Michell Bearings, Kemp recently contacted Tony Lewis of Thame Workholding.

“After studying our new machine’s specification and capabilities, while also considering our objectives, we concluded that a work-holding arrangement, incorporating Thame Workholding’s Lang QuickPoint system and Samchully jaw boxes, would be ideal for our needs,” says Kemp. “By working together, Tony and I developed a system incorporating Thame Workholding’s products that has considerably reduced our new machine tool’s set-up and job change-over times, while greatly increasing its production availability. In addition to boosting efficiency, our new work-holding system’s ability to securely grip workpieces helps us to guarantee that the required levels of accuracy and surface finish are achieved on
a consistent basis.”
The work-holding arrangement conceived by Lewis and Kemp consists of several circular ‘slave’ plates that can be set-up offline. These slave plates have Lang QuickPoint studs attached to their bases and a series of QuickPoint plates that remain loaded on the machine table. The slave plates also feature T-slots that allow Samchully jaw boxes to be moved into position, tightened on to the workpiece, then centralised ready for machine loading.
On completion of a machining routine, the slave plate holding the finished part can be removed by crane, after which the next slave plate holding the new workpiece can be lowered into position. Upon quickly securing the new slave plate to the machine’s table, the next machining operation can begin.
The Hermle CNC machining centre’s spindle is able to move clear of the table, a useful capability that ensures the working area is completely unrestricted and accessible. As a result, completely unhindered crane loading is possible from directly above the machine table’s centreline.
According to Thame, the Lang QuickPoint system provides precise and repeatable mounting of fixtures and other elements on to machine tables, indexers, cubes, rotary tables and mill-turn machine tools. QuickPoint’s height of only 27 mm makes it the lowest profile zero-point-system currently available, says the company. Manual clamping is achieved with just one tightening screw (hydraulic or pneumatic clamping is also possible). The use of this simple and sturdy system allows a maximum pull-down force of 6000 kg.

“The QuickPoint location system is based on four wedge bolts in the pallet that engage with four grooved locating bolts screwed to the vice or fixture,” explains Lewis. “The highly repeatable nature of QuickPoint guarantees that Michelle Bearings’ slave plates can be loaded with workpieces off-machine, then quickly and precisely attached to the Hermle machining centre’s table. Now, rather than wasting valuable time setting-up a workpiece when the machine is idle, then performing machining operations as subsequent activities, these processes are capable of being completed concurrently within the machine’s cycle time. Deploying this strategy can help deliver outstanding machining efficiencies.”
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Fabricator reports flood of new work

Established in 1967, Stevens & Carlotti produces metal fabrications at its Sandwich, Kent factory for customers in the UK and continental Europe. A jump in turnover of 25% in 2017 compared with the previous year looks set to be followed by a further 50% increase in 2018, which has unsurprisingly caused some production and logistical issues. The situation has resulted in an increase in headcount from 70 to 100 staff in the past 18 months, as well as a £1.5m investment in new machinery since September 2017.

Part of this sum was allocated to the purchase of a Bystronic fibre laser-cutting machine of 3 x 1.5 m sheet capacity, together with two press brakes from the same manufacturer. The three machines are installed in one unit, forming a lean production cell on the Sandwich site for processing mild steel and aluminium from 1 to 25 mm thick, and stainless steel up to 15 mm.
Managing director Marco Carlotti says: “Orders have flooded in recently across the board for batch sizes ranging from one-off to several thousand. They are being placed by existing and new customers, from sectors such as power generation and pumps, through street furniture and road sweepers, to electronics, filtration and construction. Our success is partly because we offer a complete subcontract solution, including cutting, bending, machining, welding, assembly and painting.
“Several cutting methods are in use here, each of which has specific advantages that give our customers best value for money,” he adds. “Laser cutting is the lead technology, however, and we have been using CO2-powered equipment for nearly 20 years.
“Due to the current higher level of business, we decided to replace one of our two second-generation 4 kW CO2 machines with a Bystronic ByStar Fiber 3015 fitted with a 6 kW power source and a ByTrans Extended automated sheet loading and unloading system. The benefits have been astounding. On thinner sheets, say around 5 mm, the machine is four to five times faster, accuracy of cut is better and it is possible to produce finer detail than on a CO2 machine. Fibre laser cutting is also not so expensive to run, as it consumes less electricity, does not need any laser assist gases and maintenance costs are lower.”

At the end of 2016, Carlotti visited the Euroblech exhibition in Hanover where it was obvious to him, and his two accompanying machine operators, that fibre technology had moved forward so quickly that it had become the new standard in modern laser cutting. Both of his incumbent CO2 laser-cutting machine suppliers offered a fibre alternative with automation, but he decided in favour of Bystronic following a visit to see the machines being built in the Swiss factory, which he describes as “impressive”.
The ByTrans handling system provides the best of both worlds in that it stores up to 6 tonnes of material, enough typically for a couple of hours’ lights-out production at the end of a day shift. Yet it also allows convenient manual intervention at a moment’s notice to fulfil a rush job if necessary. A tower system would not have been so flexible, due to the difficulty of accessing the shuttle table to place a sheet by hand.
Another feature of the ByStar Fiber that Carlotti likes is the control system, on which the interface is more akin to that of a tablet than a PC, making entering a program for an interim run easier. Conveniently, the same BySoft 7 software in the CNC system is also to be found in the controls of the latest Bystronic Xpert 150-tonne/3 m and 40-tonne/1 m capacity press brakes on site (the fabricator’s fourth and fifth from this source over the past 10 years). This software synergy speeds throughput when a component needs to be both laser-cut and folded.
An extra piece of Bystronic software that is about to be harnessed at the Sandwich facility is Plant Manager, which will provide visual support to the machine operator when planning which materials to stock near the machine for the next jobs, and when unloading cut parts. All components belonging to a particular customer order can be colour-coded on the cutting plan so that they are distinguishable from parts associated with other orders. Moreover, the first and last cut component can be labelled so that the operator knows when an order begins and when it is completed.
Carlotti concludes: “We have been impressed with the performance of the ByStar Fiber. The only problem we have is that it is so fast it can be difficult at times to feed the machine with the next sheet quickly enough.
“We are going through a major reorganisation of our site at present,” he continues. “As part of that, we will be rearranging the cantilever racking holding material for supply to the ByStar Fiber and will also be redesigning the breakout area to speed parts removal. If business remains buoyant and carries on increasing the way it has over the past couple of years, we will be looking to add an extension to the factory unit and integrate a tower storage system with the ByTrans to expand the cell’s automated production capability.

“Overall, the efficiency and accuracy of fibre laser cutting are allowing us to deliver competitively priced goods in a highly competitive industry, without having to compromise on quality or service. It is also helping to mitigate today’s higher material costs, so we do not have to eat into our margins too much.”
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Restormel takes first five-axis steps

Being located in a picturesque corner of Cornwall poses no problems to Restormel Machine as the company grows its business, with customers from all over the UK recognising its ability to deliver on-time to high quality standards for turned and prismatic parts. Maintaining this reputation has been achieved through a programme of investment, with most of its extensive machine tool capacity being under three years old. The company’s purchase of an XYZ 710 vertical machining centre with five-axis capability is the latest example of meeting customer expectations.

In addition to ongoing investment in machines and people, Restormel Machine’s managing director Barry Kennett highlights other factors that have seen the business grow significantly since it was founded as an owner/operator concern over 30 years ago: “We have had a natural progression over the years based on our ethos of providing efficient service and high quality. We also took a decision not to focus on any one industry sector, which has protected us to a degree from downturns, such as that seen recently in the oil and gas sector. Above all, we are happy to throw time and effort at jobs for customers to ensure that we build relationships and that they get what they want or expect. By providing this high level of support we overcome any perceived issues with our location. The overriding factor though, is that we must invest to move our business forward. If we don’t buy better, faster, more efficient machines we will just end up going backwards.”
As an already a committed customer of XYZ Machine Tools, with nine machines installed, when Restormel Machine was approached with some new work that would benefit from five-axis machining, it turned once again to XYZ. While the UMC-5X simultaneous five-axis machining centre is the flagship of XYZ’s VMC range, Kennett didn’t feel that he was ready to go to full five-axis; space was also a limiting factor. Therefore, he looked once again at the XYZ 710 VMC, of which he already had two, one of which with fourth-axis capability.

“Five-axis was definitely the next step for us, but with the pressure on space and our experience, going with the 710 VMC with a Lehmann five-axis unit fitted was the right move. This met our immediate requirements and has also opened other opportunities to bring in five-axis work. Additionally, while the move to five-axis was a learning curve, it has also encouraged us to review existing work that we produce using three- and four-axis machines. The result is that we are finding significant improvements in cycle times.”
These savings are highlighted by one component that was machined on a combination of three- and four-axis machines; the total cycle time across the two set-ups was 2.5 hours. By transferring this part to the XYZ 710 VMC, with the Lehmann fifth axis unit, cycle time was cut to just 50 minutes. In addition to improved machining times, having the additional axis also allows single set-up machining to be carried out, bringing additional productivity gains, with work in progress reduced as parts are not waiting around for the next operation.
“Having this capability has definitely helped us to not only secure existing contracts, but win new business,” says Kennett.
Another benefit of choosing the XYZ 710 VMC is the Siemens 840D ShopMill Control. Like many businesses, finding the right skilled people is a challenge, one that Restormel is addressing through apprenticeships. The Siemens control with its ‘JobShop Concept’ helps to overcome any skill/experience issues as it is truly conversational and provides easy to understand prompts in order to create simple and complex programs in the background.
The end result can then be viewed in plan, three planes or full 3D, to provide the reassurance that a user may need.
“The control is so easy to use and straightforward enough that our operators are able to switch from other machines using different brands of control,” says Kennett. “So confident in it are we that the machine is operated on a regular basis by one of our apprentices, who is using it to advance his skills set. “When he is not at college he is setting, programming (in five axes) and operating the machine without any issues whatsoever.”

The XYZ 710 VMC installed at Restormel Machine features axis travels of 710 x 450 x 500 mm in X, Y and Z, with a table size of 760 x 430 mm, which the company makes full use of, with multiple set-ups on the table at any one time. Based on a solid cast iron structure, the machine features box slideways on all axes; the rigidity generated by this construction allows Restormel Machine to maximise available cutting-tool technology with increased cutting data. This is backed up by the 17 kW, 8000 rpm spindle, 20 m/min rapids and 24 station arm-type tool changer fitted as standard.
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Edgecam programs merged into single machining files

Mould maker Kavia Tooling has developed its own machining strategies to run multiple CNC programs at once by merging several of them into a single file; many containing around 1.5-million lines of code.

Working out of 9000 sq ft premises in Burnley, with 15 employees, the company produces around 80 mould tools a year for plastic injection moulders, ranging in size from small tools of 156 x 156 mm, anywhere up to 2 tonnes. Key to the company’s throughput, Kavia has invested heavily in customising a range of software and equipment, including CAM solutions from Edgecam, and a Pioneer co-ordinate measuring machine (CMM) from Hexagon.
Edgecam drives seven high-speed CNC mills with spindle speeds varying from 12,000 to 30,000 rpm, and Sodick EDM machines, but production director Mark Cole says it’s no ordinary machining process: “Edgecam has customised the software to create a system for us which we call Merge. It means we can put several components on the machines at once, and the Edgecam CNC code for them is all merged into one large program, along with the datums to set the parts on.”
He cites a recent example when the company was working on two cavity plates on one side of the machine, and four inserts on the other. “We put the individual Edgecam CNC programs for each component together into one file, and it all went to the machine as one large program.”
The Merge strategy also helps to keep cutting tools to a minimum, by looking at information such as duplication, length and tool quality in all the programs. “For example, if there were two repeating cuttings tools in the individually merged programs, it selects the best one for the manufacturing process,” says Cole. “It goes through every single NC program and rearranges all the tools accordingly.

“If we have 10 components that can all fit on the machine, Merge puts the tool information for all 10 programs together: the datum setting information, part setting information, the pre-setter, everything,” he adds. “So as far as the machining is concerned, it’s just one big product.”
Cole says the benefits are “unbelievable”, creating a completely standardised system: “The customised software works for us exactly how we want it to, and everyone from the CAM programmer to an apprentice setting the tools, works in the same way. It demystifies shop floor activities and eliminates error.”
Kavia Tooling’s most recent investment in customisation is the unusual way of using a Hexagon Pioneer CMM. Rather than checking finished dimensions and ensuring a part is manufactured within tolerance at the end of the manufacturing process, Hexagon wrote a piece of customised software to enable Kavia to find offsets at the beginning of the operation.
Known as ‘Zero Transfer Fixture Plates’, this particular customisation means that instead of having to put each part on the machine and set it, the component is set on the CMM, which gives Kavia the X, Y, Z and U orientation. This can be done with any number of components, and the information is transferred to the machine through the Edgecam Merge software. Merge uses the data to add a programmed work offset and co-ordinate rotation into the appropriate merged programs.
“We only have to put the Zero Transfer Plate, which is micron-accurate, into position on the machine, and it knows exactly where the part is, so we don’t have to set it,” explains Cole.
The end result is a CNC program which can produce several parts at a time, without the need to use the machine as a set-up station as all preparatory operations are now carried out offline.
“Without the CMM, if we were setting up a component square on the CNC machine for example, we’d have to ensure it was perfectly in line with the machine’s axis,” says Cole. “If we were doing that for 10 components, the process would be prone to error, especially where there are overhangs. But setting them on the CMM means everything is done automatically, because it tells the machine the angle of the part.
“To set up six fairly difficult components directly on the machine might take one day, during which it’s not running,” he adds. “On the CMM it’ll be one hour, and you can be totally confident they’ll be absolutely accurate.”

Edgecam engineers also worked with Kavia Tooling on customising the software further, to set tooling data for the CNC programs offline by utilising data from the company’s Zoller tool pre-setter system. Previously, the operator had to manually set all the tools for each job run, with the same costs and risks associated with datum setting.
“Now, Zoller captures the required tool information for all the programs, and Edgecam merges it into the final CNC file,” says Cole. “It used to be a skilled job, but today a first-year apprentice does it.”
With some of the merged programs coming out at around 36 MB and containing up to 1.5-million lines of NC code generated by Edgecam, they can take four days to run.
“Our machine tools are generally operating 24/7, as they’re expensive and need to be running as long as possible,” states Cole. “A lot of our investment in bespoke software and automation was to create an environment where the machines are running while we’re doing as much preparatory work as we can offline.”
Kavia Tooling’s general philosophy is to run smaller programs during the day, and longer ones unsupervised overnight.
“We’ve also created a lot of systems through Edgecam where we combine a number of smaller runs that would each take half an hour, into a 12-hour night run,” he says.
“Edgecam is absolutely integral to our entire manufacturing process. It’s at the heart of everything, and is vital in terms of what it does through customisation, standardisation and the removal of errors.”
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Pocket rocket goes even faster with HyperMill

When Vetech Product Design & Development first opened its doors for business in 1994, the founders of the Buxton-based company exploited their expertise in the garden equipment sector to win business from Bosch. Providing design, consultancy, subcontract manufacture and mould and die tooling, the business has retained Bosch as a core customer while branching into the military, general subcontract, electronic sensor and plastic moulding sectors.

This diversification has been a welcome respite for a company that has noticed a dip in European business during the Brexit process. However, not a business to rest on its laurels, Vetech has applied its expertise to the motorsport sector, converting a Suzuki Hayabusa motorcycle engine for use in the Mark I to VII Mini produced from 1959 to 2000. It is here the expertise of CAM developer Open Mind Technologies has come to the fore.
The subcontract company has a plant list that includes manual and CNC machining centres, injection mould machines and test facilities. Part of the acquisition trail includes a Hurco VMX42M and a VMX30Ti machining centre, with the larger VMX42M being retro-fitted with a fourth-axis rotary unit two years ago. Designing and manufacturing complex aluminium mould tools, military sensors and the Hayabusa engine, the previous CADCAM system was struggling to cope.
Commenting upon the situation prior to the arrival of Open Mind’s HyperMill CAM system, Vetech’s senior design engineer Andy Smith says: “Our longstanding CAD package had an integrated CAM system that we were using for all our machining tasks. One day we machined a mid-housing part for our Hayabusa engine and the VMX42M did a rapid traverse between two points, crashing into our fixtures and ruining the spindle. The result was weeks without the machine while we installed a costly new spindle. The lack of collision detection was a major cause for concern. We then programmed a gear selector barrel that proved almost impossible with our old package. We needed to change our CAM software and invited all the leading vendors to present their solutions.”
Being an experienced CADCAM designer and programmer, Smith has knowledge of all major CAM packages, coincidentally being one of the first UK engineers to be trained on HyperMill in the mid-1990s during previous employment at the Hyde Aerospace Group.
“Re-designing and re-manufacturing the Hayabusa 1300 cc engine to fit into a Mini meant we had to re-position the gearbox and add a reverse gear,” he explains. “I gave the gear selector barrel to all the leading CAM vendors and asked them to program it. Open Mind provided the most efficient and productive solution with an intuitive presentation that detailed the benefits of HyperMill over its competitors particularly well. Due to our previous experiences, collision prevention was a critical factor, something Open Mind certainly convinced us of. Furthermore, we needed to achieve faster programming times for our aluminium mould tools; HyperMill was once again streets ahead for mould tool programming.”

Re-engineering the Suzuki Hayabusa engine is undoubtedly an impressive feat of engineering that has genuine purpose. Once the power unit for the world’s fastest production road bike, the Hayabusa engine is a compact and powerful powertrain unit that can fit straight into the classic Mini while offering reliability despite the massive increase in performance. Such reliability is a rarity for any classic car.
The repackaged engine has seen Vetech engineers retain many of the power-producing components of the original Hayabusa. However, the conversion has seen the company add internal final drive gears and a differential, and re-position the gearbox beneath the engine, as well as introduce a fully integrated reverse gear. The engine has been turned back to front. Here, the repackaged engine/transmission has ‘universal’ engine mounts; bespoke mountings have been designed and manufactured for the mini but the engine mounting bosses provided permit easy integration into other vehicles such as the Fiat 500 or Lotus Elise.
Even the most powerful production Mini variant ever only developed 96 bhp, although the vast majority of Minis only offered around 65 bhp or less. An exceptionally highly tuned model can generate upwards of 120-130 bhp, but with very low reliability as a consequence. The Hayabusa engine has a power output of 197 bhp as standard and when re-packaged by Vetech, it weighs just 100 kg. This is a 32% engine weight reduction over the original unit. For those with an inclination for seemingly jet-propelled speed, Vetech also offers a super-charged 300 bhp unit.
During the development phase of the Hayabusa project, Vetech entered the 2016 ‘Fastest Mini in The World’ race at Brands Hatch. Starting in last position on the grid, the power to weight ratio propelled the car to second position in just three laps, only failing to win the race due to a water pump problem.
Programming the 11 core components of the re-modelled engine with HyperMill, Vetech has certainly benefitted from the CAM system, as Smith continues: “Programming and machining the Hayabusa project is not time-critical. What is important for us is the ability to program and machine complex parts with confidence in the collision avoidance system. Open Mind has completely modelled the work envelope into the CAM system with fixtures, machine spindle, tool holders and the Hurco fourth-axis rotary table all factored in. HyperMill stores a complete library of tool holders and tools, so we have 100% confidence in the anti-collision system. From a time-reduction standpoint, we programmed an aluminium mould tool for Hayabusa inlet and exhaust caps. With our previous system it took 20 hours to program and with HyperMill this same tool was completed in less than 10 hours.”
The upper housing of the engine consists of seven individual set-ups. With its previous CAM package, Vetech could not carry the stock model from one process to the next.
“Without the ability to carry the stock model forward to the next set-up, we would have to manually jog through the cycle on each set-up to minimise non-cutting times or run the program and wait for the tool path to finish ‘fresh-air’ cutting,“ says Smith. “The stock model feature within HyperMill eliminates fresh-air cutting and enables us to maximise machine utilisation at every set-up. This makes huge savings on complex parts with multiple set-ups.”
With over 60% of Vetech work consisting of aluminium mould tool production, the manufacturer programs the cores and cavities with HyperMill and simultaneously machines the two mating tool components overnight on the two Hurco machining centres.

To reduce lead-times, Vetech has invested in two HyperMIll seats, so one team member can program the core, while another programs the cavity. “We undertake prototype design, development and testing work on lawnmowers and there is often an urgency to respond to the customer. In most cases, we are expected to design, program and manufacture the mould tool [cavity and core] and then mould the plastic prototypes and conduct thermal and stress tests within 3-4 days. To achieve this, our programming and machining times have to be extremely efficient.”
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