When BCT Engineering opened its doors for business over 30 years ago, the Woking-based company began making its revenue from producing performance parts for motorcycles. Over the past three decades, this activity has evolved into the automotive, automation, offshore, aerospace and motorsport industries. With a concerted effort to accelerate productivity, the subcontractor has enlisted the support of cutting tool specialist Industrial Tooling Corporation (ITC).

Stating the impact that ITC has had on the subcontract business, BCT Engineering’s managing director Tony Ryan says: “The help we’ve had from ITC has been invaluable. We have one product that is part of a modern ‘touch-button’ domestic tap for boiled or chilled water, and we were initially making the parts from plate material. However, we had problems that were down to both the type of material and the machining methods we were applying. ITC came along, had a look at the way we were machining the parts and changed the tools and the machining strategy. This has saved at least an hour on each component.

“To achieve this, we are using a combination of tooling that includes high-feed tip tools to go around the outside of the part and a solid-carbide end mill to go through the centre of the component. When we started to machine the part, we were going far too cautiously with the speeds and feeds, as we didn’t realise the performance parameters of the tools. Now, we have evolved the situation and drastically reduced the cycle times, while process reliability has also been improved.”

Commenting upon the domestic tap component, ITC application engineer Matt White says: “The task for the tap parts was for them to be machined in a shorter time, while maintaining a safe and reliable process. Tony had the idea to change from making one component at a time, to machining two simultaneously. We looked at the job in some depth and recognised that applying a combination of indexable tipped tools and solid-carbide end mills was the best route forward. In this case, we applied the Widia M370 high-feed indexable end mill to machine the profile of the parts and then used an ITC 20 mm diameter solid-carbide five-flute 5021 cutter to rough machine the slotted form in the centre of the parts. The final step was the application of an ITC solid-carbide six-flute 6051 long-series finishing tool.”

From a process stability perspective, White adds: “We are now looking at machining five billets per indexable edge of the high-feed Widia M370 on 316 stainless. With a 0.6 mm depth of cut and 180 m/min spindle speed, and a feed rate of 0.5 mm/tooth, this is a very productive run time. What Tony now knows is that he can let the job run and leave the machine to do other tasks; he is guaranteed to return to the machine at a later time with five billets reliably machined.”

The stainless steel tap components are machined in batch sizes of 50-off pairs/sets, and the machining time of four hours per pair/set has been cut from 4 hours to 2 hours, a 50% cycle time reduction for BCT Engineering.

Looking at another component, an aluminium laser casing that is produced in batches of 20-off, the application expertise of White once again managed to reduce cycle times; this time by over two hours per part. Referring to the opportunity to work on this project, White says: “After successes on stainless machining at BCT, I had the chance to run the 40 mm diameter VHSC Widia cutter to rough-out pockets on large aluminium casings.

“Previously, BCT was using a slightly different tool on the job and we were only able to run at a feed in the region of F2000. With the new ITC Widia VHSC tool, we can run at F3500, while doubling the depth of cut. This is saving us at least an hour per component, just from the pocket machining. The total savings are significant as we machine a relatively large quantity of these parts.”

With regard to tool life and performance, White says: “Using the three-tipped Widia VHSC indexable tool, parallelism has improved, tool life is much better and performance is fantastic. BCT has some aluminium casing type jobs for which we needed to remove cycle time; the Widia VHSC series has been very successful at this task.”

Concerning the cutting parameters, White says: “The cutting data on this job is dictated by the maximum spindle speed restriction of 8000 rpm. However, we have managed to run the VHSC at 7000 rpm with a 5° ramp-down angle to a 3 mm depth of cut, and then we run around the pocket at almost 3500 mm/min.

“Previously BCT was utilising the conventional Widia VSM11 tools, which is like the APKT style insert. The trouble with these standard 90° shoulder mills is that they inherently cannot be fed very fast on aluminium. So, in the past it may have been better to run with a larger solid-carbide multi-flute tool than use indexable tools. With the new VHSC, we have the option to run much faster. For example, you can go from 0.1 mm per tooth for a standard shoulder mill to 0.3 mm per tooth and beyond with the Widia VHSC. In addition, you can really get the spindle speed up; we are looking to run a 50 mm diameter tool at speeds around 12,000 rpm with 6000 mm/min feeds.”

Despite removing the material much faster, the surface finish is actually improved, as White explains: “The more you push these tools by running higher feeds and higher revolutions, the better the surface finish. From a tool life perspective, BCT haven’t changed an insert edge yet. This may not be good news for our area sales representative, but it’s certainly good news for Tony and BCT.”

Concluding on the service from ITC, Ryan says: “We now buy virtually all of our cutting tools from ITC. Most cutting tool manufacturers would not be able to give us the service that ITC has provided. Matt White and Dave Cleeve have spent upwards of two to three days initially sorting these two jobs for us, with continued follow up visits to further improve performance. The results have been fantastic and we are delighted by their commitment to help our business.”
For further information www.itc-ltd.co.uk

At the Market Overton factory of subcontract machinist Hi-Spec Precision Engineering, five Hurco machining centres and various other machine tools are to be found producing parts from mild and stainless steels, bronze, brass, aluminium and plastic over a single daily shift from Monday to Friday. Nothing unusual there, but the weekends bring a different and unexpected role for two of the Hurco machines.

On Saturdays and Sundays, Hi-Spec’s owner Darren Grainger and his brother Gavin indulge their lifelong passion for music by milling electric guitar bodies from solid wood. Initially they used CAD files downloaded from the internet, but latterly have produced five designs of their own, including one for a bass guitar. This hobby is proving lucrative, as some of the instruments sell both at home and abroad for up to £3500 under the brand name Grainger Guitars, which is owned jointly by Gavin and Darren.

Gavin says: “To produce the guitar bodies, necks and other parts from wood, we now mainly use a Hurco VM30i machining centre and sometimes also a smaller VM5i, both three-axis models that were installed in 2017. However, we started out two years earlier using other machines and began selling guitars in 2016 at exhibitions around the UK.

“All that’s needed is to wipe down the machine table on Saturday morning and block off the coolant nozzles to prevent ingress of sawdust,” he continues.“When we’ve finished profiling wooden components, we simply vacuum out any wood residue, clean down the machine, uncover the coolant holes and we’re ready to cut metal again on Monday morning.”

A large and exotic array of woods is used in the creation of the guitar bodies. Early materials were maple, alder and poplar, but lately the Grainger brothers have introduced swamp ash, mahogany, ebony, wenge, walnut, buckeye burl, limba, purpleheart and some wood/resin composites. Pearl and stone materials are also machined on the Hurco machines for the marquetry inlays.

Router cutters were used at the outset, but solid-carbide end mills and ball-nose mills designed for machining aluminium were found to produce a much better result, as the sharpness of the cutters virtually eliminates burrs and produces a fine surface finish. This strategy is consistent with the final use of ultra-fine, 2000 grit sandpaper with an average particle diameter of 10 µm to smooth the wooden components prior to the application of multiple coats of gun barrel oil to achieve a lustrous finish.

Everything for the guitars is manufactured in-house, including all metal components, apart from the pick-ups and their associated electronics. Unlike the wooden elements, the turned and milled metal parts are sold to other guitar builders worldwide over the Internet, forming another profitable sideline.

Commenting on the company’s main subcontracting business, Darren says: “In 2015, we invested in a second five-axis machining centre from Hurco, a VM10Ui, and at the same time upgraded the control software on a similar, pre-existing model to the manufacturer’s WinMax 10. The five-axis machines are used mainly for producing components using 3+2-axis strategies programmed conversationally directly at the control.

“Two years later we installed the VM5 and part-exchanged a small Hurco VM1 machining centre for the VM30i with a 1270 x 508 x 508 mm working volume so that we could produce larger metal parts for rock crushers,” he adds.“It is this machine that is also the mainstay of wooden component manufacture for our guitars.”

Darrensays that the Hurco control system on the latest machines has a smoother, more convenient touchscreen graphical user interface. Scrolling through fewer menus allows the operator to arrive at the required screen more quickly. Even a simple operation like entering a code to jog the axes while the doors are open is easier, without having to go through the diagnostics screen.

In addition, WinMax 10 software enables faster cycles through the use of Hurco’sUltimotion and Adaptipath control software, which has look-ahead and optimisation capabilities that reduce cycle times, especially when milling the corners of multiple pockets. The tool-change optimisation feature is also helpful, as it automatically rationalises the number of cutter exchanges for optimal efficiency.

“We have been able to save a lot of machining time through a combination of the latest Hurco software plus the use of trochoidal milling with solid rather than inserted carbide end mills,” says Darren. “In some instances, we have more than halved cycle times. For example, we produce batches of 38 puller ends for hydraulic tooling two at a time from EN24T billets in two operations on the VM30i in a cycle that previously took more than four hours.

“Now, taking a 16 mm depth of cut with a solid-carbide, 12 mm diameter end mill at 6 m/min feed rate, and using Hurco’s twin-nozzle coolant delivery together with the standard air blast facility – which incidentally is used on its own when machining wooden components – the same job takes approximately two hours.

“In another case, production of a steel matrix used to take 40 and 35 minutes for ops 1 and 2 respectively, which have been reduced by an even greater percentage to 17 and 12 minute cycles.”

Hi-Spec Precision Engineering is continuing to grow, despite operating with fewer staff compared with two years ago, so profitability is up. The hydraulics sector accounts for around 40% of turnover, with the machined components frequently finding their way into hydraulic actuators and valves, rock crushers and access platforms. Automotive and agricultural parts are also routinely produced at the Market Overton factory.

Batch sizes range from one-off to hundreds for prismatic machining, while production runs on the company’s six CNC lathes can be in the thousands. Customers stretch from the south coast of England across to Norfolk, and as far north as Scotland.
For further information www.hurco.co.uk

Southern Manufacturing & Electronics returns to Farnborough on 5-7 February 2019. Already nearing its maximum capacity, machine tools are emerging as one of the key features of the show.Many of the familiar big-name vendors of machine tools and associated equipment will return for Southern 2019, including Bystronic, Bruderer, Dugard, YMT and Haas among many others.

The 2019 show also sees the welcome return of some established brands which have not been seen for over a decade at Southern Manufacturing. For instance, Citizen Machinery UK will exhibit for the first time since 2007, joined by other notable former exhibitors such as Mitutoyo UK, Schmidt Technology, Filtermist and Hainbuch UK. Admission to Southern Manufacturing & Electronics 2019 is free.Farnborough Exhibition and Conference Centre offers free on-site car parking and is easily reached by road, air or public transport.
For further information www.industrysouth.co.uk