PRODUCING LARGER MOULDS TO HIGHER ACCURACY

Moorland Toolmaking in Batley, West Yorkshire has been a user of Hurco machining centres since 1985. The company was first attracted by the supplier’s Ultimax twin-screen control fitted to a KMB1x knee-type mill, on which a program could be created conversationally at one screen while a graphic of the part was automatically generated on the other.

Tool-room manager David Gibson recalls: “Its ease of use was perfect for a tool-making environment, where one-offs are the norm. Some 35 years on, we now operate 10 Hurco three-axis CNC machining centres due to their reliability, good performance and competitive price. All of them feature a similar control, although now the software – WinMax – is Windows-based and much updated in functionality.”

He points in particular to the patented Ultimotion feature with up to 10,000 blocks of dynamic variable look-ahead, which automatically determines the optimal trajectory for the cutter around the workpiece. This feature keeps the programmed feed rate consistent and increases speed when machining around corners, reducing cycle times and improving surface finish. According to Hurco, Ultimotion is better than the smoothing features offered by CADCAM software and improves upon CAM output by providing better machine kinematics.

Even today, with mould tools being considerably more complex than in the past, the tool-making and refurbishment specialist’s operators still write 30% of programs at the control, mainly the simpler ones for producing bolsters and plates. The remainder are prepared offline in Autodesk CAM from customers’ CAD models.

Moorland Toolmaking’s largest Hurco machine is a VMX64Ti with a 1625 x 864 x 762 mm working volume. In March 2020, the toolmaker invested in a slightly smaller BX50i double-column, bridge-type machining centre with a 1350 x 950 x 600 mm envelope for producing tools weighing up to 2.5 tonnes to even higher accuracy.

The BX50i is also used for producing other large components subcontracted out to the firm, a part of the business that currently accounts for 10% of turnover and involves not only milling but also turning, spark erosion, wire erosion and deep-hole drilling. On the tool-making side, which accounts for the other 90%, around two-thirds of output goes to trade moulders serving the automotive industry, and the rest to sectors such as white goods and garden wares.

Moorland Toolmaking’s new, 13-tonne machine represents a step up in accuracy and performance compared with the other prismatic machining equipment in the 16,000 sq ft Batley factory. The HSK-63A spindle speed is 18,000 rpm, up 50% on the previous maximum on site; scales rather than encoders provide feedback of linear axis positions; and thermal compensation measures have been incorporated throughout the machine.

Gibson says: “We saw the BX50i on the Hurco stand at the last MACH show and were impressed at its robust construction. Since the machine was installed, we’ve been holding dimensional tolerances of better than ± 25 µm and we expect that level of precision to be long-term.

“We also find that moulds coming off the machine have a better surface finish which typically needs 30% less polishing,” he adds. “It’s a big saving, especially on large tools that can take up to a month to machine and then a further week to hand finish.”

Gibson says that the higher spindle speed is a further advantage, as smaller diameter cutters can be used so fewer features need to be sparked out, saving the time and cost involved in transferring tools to a die-sink EDM machine and of making copper and graphite electrodes on the other Hurcos. In any case, milled features like deep ribs are quicker and easier to polish than if they are sparked, as the latter operation leaves a hard recast layer.

Despite being a satisfied, long-time Hurco machine user, Moorland Toolmaking considered two bridge-type machining centres offered by other potential sources. What really swung the decision in favour of the incumbent supplier was the generous 950 mm Y-axis travel on the BX50i, 150 mm more than was available on other machines of equivalent footprint (approximately 4.5 sq m).

Consequently, the table will accommodate a 1-m wide workpiece, extending the size of component that can be produced in one hit rather than having to reposition it on the table. The table also extends the size of part that can be tackled in two hits.

“The BX50i was delivered the day the country was locked down due to COVID-19,” says Gibson. “Hurco engineers did a great job installing the machine in difficult circumstances, with some of their staff on furlough. Since then the machine has run faultlessly during the day and we have full confidence in taking advantage of extensive lights-out running for finishing our moulds through the night, which we do frequently.”

For further information www.hurco.co.uk

MACHINING SMALL OBJECTS OF DESIRE

Mills CNC, the exclusive distributor of Doosan machines in the UK and Ireland, has supplied 17D Ltd, a family-owned miniature railway manufacturing specialist based in Matlock, with a new Doosan vertical machining centre.

The machine – a compact, high-performance DNM 4500 – was installed at 17D’s 2500 sq ft facility in July 2020, and is being used to produce a range of precision components. These parts include live steam locomotive parts (such as valve gears and cylinders), chassis components, axles, bogies, couplings, buffers and wheels. Workpiece materials extend from aluminium, through to cast iron and carbon steel.

17D, which was established in 2010, manufactures a range of scaled working models of locomotives, carriages and wagons for three miniature railway gauge systems: 5”, 7¼” and 10¼”. The company’s locomotives for the 5” gauge are produced to a scale of one-twelfth, at around 6 ft long, rising to approximately 12 ft for the 10¼” gauge.

In addition to designing and manufacturing miniature locomotives and associated rolling stock, the company devotes significant time and resources to producing and supplying high-quality, cost-competitive and quick-turnaround parts and spares. These components are destined for a myriad of UK and internationally-based customers that include hobbyists and private collectors, through to clubs and commercial organisations.

The company has a strong reputation in the markets it serves and is highly regarded. To maintain its market position and competitive edge, 17D invests regularly in plant, equipment, processes and systems. The company’s commitment to continuous improvement, combined with a dramatic and sudden upsurge in demand for its machined parts, were the driving forces behind 17D’s new DNM 4500 machine-tool investment.

Explains partner Tristan Dengate: “Business had been growing incrementally, but the onset of the COVID-19 pandemic resulted in a sharp and dramatic increase in demand from hobbyists who, having been furloughed as part of the lockdown, had time on their hands.

“This increase in demand was putting a strain on our existing machine tools so, to ensure we could meet customer expectations, we made the decision to strengthen our capabilities and invest.”

17D has a variety of CNC and manual machines at its disposal and, in November 2019, further strengthened its turning operations by investing in a pre-owned 51 mm bar capacity Doosan Lynx 220LM lathe equipped with 6” chuck, C axis and driven tools.

“The arrival of the Lynx lathe had an immediate and positive effect, helping us to reduce part cycle times, eliminate production bottlenecks and improve lead time fulfilment,” explains Dengate. “Although the machine is a few years old, it still delivers exceptional performance and hasn’t missed a beat since installation.”

The machine’s arrival and subsequent performance also ‘converted’ 17D into becoming advocates of Doosan machine tools.

“The increase in demand for machined parts, which started at the onset of the pandemic in April, was putting pressure on our milling resources,” says Dengate. “We needed additional milling capacity and capabilities, and we needed them fast. Our experience with the Lynx 220LM helped narrow down our choice: put simply, we wanted a Doosan.”

17D drew up a list of key requirements, investigated the market and approached Mills CNC.

“We needed a versatile, high-performance machining centre – one that could deliver accuracy and high metal-removal rates, combined with an ability to produce intricate part details and features, and achieve super-fine surface finishes,” states Dengate.

To help reduce part cycle times, the machine also needed the ability to cope with high speeds and feeds, and aggressive depths of cut. The company had narrowed down its choice to a DNM 4500 machining centre and, with funding in place via an EU grant, placed the machine order with Mills CNC.

Says Dengate: “We ordered the machine on a Monday and it was delivered and installed by the end of that week.”

The DNM 4500 is a high-speed, rigid and versatile three-axis vertical machining centre that is suitable for a range of applications. Standard features include a large working envelope (800 x 450 x 510 mm), a direct-coupled spindle (18.5 kW/8000 rpm), roller LM guideways and an on-board thermal error compensation system.

Among further features are fast rapid-traverse rates (36/26/30 m/min in the X, Y and Z axes respectively), a large work table (1000 x 450 mm with 600 kg maximum table load) and a 30-position ATC. The machine supplied to 17D was equipped with a Fanuc i control, but it can also be specified with either a Siemens 828D or Heidenhain TNC 620 CNC.

Concludes Dengate: “The DNM 4500 is a great addition to our operation. We’re confident that the machine will be more than instrumental in helping us to further grow our business, not just with our miniature railway customers, but with customers from other sectors looking for a proven, high-quality subcontract machining specialist.”

For further information www.millscnc.co.uk

Medical housings machined 40% faster

Established in 1989, Mildenhall-based subcontractor CTPE focuses on the medium to large volume production of high-precision components for the scientific, medical, electronics and defence sectors.

The company uses a number of three- to five-axis vertical machining centres, as well as fixed- and sliding-head CNC lathes.

To expand its prismatic machining capacity, in July 2020 CTPE invested in its first-ever horizontal machining centre, a four-axis Averex HS-450i with nominal half-metre cube working volume from Whitehouse Machine Tools, the sole sales agent for the Taiwanese HMC manufacturer in the UK and Ireland.

What prompted the purchase of the twin-pallet, 40-taper machine was an uplift from 150 to 350 per week of a particular 6061 aluminium, two-part enclosure. The enclosure is needed by CTPE’s largest customer, a medical sector OEM, for the production of critical care diagnostic equipment.

There is no problem completely machining the required quantity of covers three at a time in two hits on a Japanese-built Brother Speedio S1000X1 30-taper VMC, installed at Mildenhall last April by Whitehouse Machine Tools. Neither is there an issue completing Op2 on the matching housing using the same machine, which has now been fitted with an angle head to make the cycle even faster.
However, Op1 on the housing was proving too time-consuming on a three-axis VMC to meet the increased order level and was causing a permanent bottleneck, despite the running hours having been extended from 10 to 14 per day.

Alex Taylor, director of CTPE and son of the founder, Chris, decided that an HMC would best suit the higher production volume. The second pallet allows the next parts to be fixtured while the previous parts are being machined – automatic pallet change takes just five seconds. Dual augers remove chips that have fallen from a cube fixture, so there is no manual intervention except to empty the swarf bin after every couple of pallet changes.

In contrast, the spindle on the fixed-table VMC was idle for 25 minutes after each cycle for accumulated swarf to be cleared and the next parts clamped for machining. A further problem was that the re-cutting of chips which collected within the component risked damaging the solid-carbide tools.

An HMC eliminates that difficulty and is more robustly built than a VMC so vibration is lower, meaning that cutters last longer. The most significant benefit, however, is that four aluminium billets can be fixtured on a cube for Op1, so 24 housings are machined in a cycle time of 160 minutes. Formerly, on the VMC, only two billets could be fixtured for machining a total of 12 components and the program ran for 135 minutes. The figures equate to a production time saving of 40%, considerably reducing manufacturing cost per part for this operation, particularly as there is now minimal operator intervention.

Three potential HMC suppliers were reviewed by Alex and Chris before they made their decision. The Averex machine was chosen as it offered high quality at an affordable price and, unusually, the possibility to retrofit a pallet pool that adds a further four pallets to the existing two, making a total of six. Its tool magazine is also extendable from 80 through 120 to 220 pockets.

“The flexibility of being able to expand the machining cell on-site at an affordable price was very attractive,” says Alex. “We will almost certainly opt to do it in the next couple of years and take advantage of unattended machining to lower piece part cost when producing anything from large batches through small-lot multi-part runs to ones and twos. The other advantage of this route to automation is that it avoids the expense of buying another machine and saves space on the shop floor.

“We favoured the build quality of this 13-tonne machine,” he adds. “Although assembled in Taiwan, it includes thermal control of ball-screw nuts, thrust bearings, Y-axis servo mounting and spindle cartridge. The machine has hand-scraped surfaces for mounting the ball-screw bearing blocks and roller bearing slide ways, and it incorporates Japanese-made components, including the BIG Plus spindle, ball screws, heavy-duty roller guideways, rotary table and the tapered cones for pallet location.”

CTPE’s new HS-450i is also fast. The machine has a 15,000 rpm/22 kW direct-drive spindle, one-second servo-driven tool change, and 1g linear acceleration to 60 m/min cutting feed around the 640 x 610 x 680 mm working volume, all of which ensure minimal idle times. Maximum workpiece size is 750 mm diameter by 1000 mm high, while control is via a Fanuc 31i Nano CNC.

Whitehouse Machine Tools’ applications engineering department helped CTPE to configure the machine to suit the subcontractor’s requirements, including advising on the work holding and modifying and improving the Op1 part program that previously ran on the VMC. The HMC was therefore ready to enter full production within a few days of arrival.

In August 2020, the supplier was called upon again to convert the Op1 cover program from the Speedio to run on the Averex. This switch gives CTPE the flexibility to execute the first operation on both enclosure parts on the two HMC pallets respectively, while the customer’s call-off rate temporarily decreases before rising again in the winter.

For further information www.wmtcnc.com

ITC meets tooling needs of subcontractor

When Steve Knowles founded Newport CNC over 10 years ago, like many start-ups he bought his first machine and worked evenings and weekends in his new venture while retaining a day job. Knowles’ first port of call was to buy a Haas VF4SS machining centre and use cutting tools from Industrial Tooling Corporation (ITC).

Building its early success in the high-end automotive and aftermarket industries, Newport CNC is now entering its 11th year of business, which has been celebrated with several investments. Before the COVID-19 pandemic, the company had planned to move into a new factory and purchase its fifth Haas machine, a ST20Y turning centre. The lockdown created several obstacles, but the five-employee business has now moved into its new 4700 sq ft facility and installed its Haas turning centre.

Commenting upon the challenge, Knowles says: “Our new facility is three times the size of the previous site, and the Haas machine is the first turning centre we’ve installed. Despite the challenges of the pandemic, we’re confident that our new machine and new facility are a bedrock for us to build an even stronger business in the future.”

One of the bedrocks of the company from day one has been cutting tools from ITC and, alluding to this, Knowles says: “I’ve used ITC cutting tools for over 20 years and they’ve never let me down. More than 80% of our work is aluminium machining and ITC’s solid-carbide cutters for this material are beyond compare. I’ve had sales reps from virtually every tooling company trialling tools down the years and none of them can match the tool life, productivity, surface finishes or overall performance of the ITC range for aluminium. Over 80% of our cutting tools are now supplied by ITC and we have little interest in wasting time trialling alternate tools; time has proven that we’re already using the best tools available for our business.”

The Milton Keynes company typifies subcontract manufacturing by serving the aerospace, electronics, medical, motorsport and automotive sectors, manufacturing everything from commercial airline seats and high-end bespoke automotive work, through to participating in the recent Ventilator Challenge. Offering three, four and five-axis machining, as well as Y-axis turning capability, Newport CNC is well equipped to meet industry’s demands. With 75% of the company’s work revolving around aluminium machining and the remaining 25% being a mixture of titanium alloys, plastics and stainless steel, ITC has been instrumental in the tooling strategies adopted by Newport CNC.

For a number of years, the ITC 3081 solid-carbide end mill for aluminium has been the go-to cutter.
“We started with several ITC solid-carbide end mills, but found our sweet spot with the 3081 series for high-feed machining – it has been a revelation,” says Knowles. “The metal removal rates are beyond compare and the surface finishes are outstanding. We’re using these end mills for everything from high removal roughing through to pocketing, profiling and finishing.”

With such a glowing reference for the 3081 series, Newport CNC now uses the range with diameters that include 3, 5, 6, 10, 12, 16 and 20 mm, with a selection of square-end and corner radii from 0.5 to 3 mm.

As the company has evolved, so has its reliance on the range of products from ITC. The company has subsequently adopted the Britcut series of two and four-flute end mills in diameters of 4, 6, and 10 mm. With centre cutting, facet relief and a 30° helix, Newport CNC has selected the TiAlN-coated option for machining various materials. The success of both the 3081 and Britcut range has since paved the way for the introduction of the 3152 three-flute, short-length AlTiN-coated end mills, the 2112 and 2012 series ball-nose end mills for profiling, and the 4071 series of chamfer tools.

ITC has been a longstanding distributor of Widia solid-carbide end mills, so when it widened its scope by adding Widia indexable tools, Newport CNC trialled the Widia VSM11 high-feed 40 mm diameter face mill. Comparing the Widia VSM11 against an industry-leading manufacturer, the VSM11 outperformed the competitor with a tool life improvement of 30% and a productivity increase of 40%, all while reducing the cost-per-insert against the previous tool. The business has since added the VSM11 80 mm diameter face mill to its inventory list.
As a relatively small subcontract machine shop that serves a multitude of sectors, Newport CNC can never second guess what type of work will be coming through the door next.

“We have a standardised tooling strategy on each of our machining centres,” explains Knowles. “Each machine has a 24-tool capacity and the first 10 positions are standardised across all of them. The first two tools are the 80 and 40 mm Widia VSM11 face mills. We can change the inserts from the XDCT aluminium grade, and geometry to the XDPT steel insert designation, in a matter of minutes. This prepares us for rough machining and facing every job that comes through the door, regardless of whether its aluminium, steel, stainless or heat-resistant alloys. It also keeps our inventory and costs to a manageable level.

“Positions three through to 10 are ITC solid-carbide end mills,” he adds. “Once again, the 3081 series plays a prominent role with a 16 mm diameter end mill featuring a 1 mm radius slotting into position three. Tool positions four, five and six also house 3081 series end mills, in diameters reducing from 10 to 3 mm. These first six positions give us complete flexibility for everything from high-feed roughing and facing, down to slotting and finish-machining operations.

“In our other prominent tooling positions, we have 3 and 6 mm ball-nose tools that support all our needs when it comes to intricate machining, profiling and finishing of precision features. Beyond these positions, we have a spot drill, chamfer tool and a couple of standard tap sizes, which leaves many carousel positions free. We can rapidly fill these positions if new jobs with challenging features or material types arrive. This strategy allows us to standardise our tool positions and overhang lengths, while giving staff familiarity with the system.”

For further information www.itc-ltd.co.uk

Machining costs flattened at Gardner Aerospace

As one of Europe’s largest manufacturers of aerospace components, Gardner Aerospace places huge levels of pride in its precision, quality and cost-efficient streamlined manufacturing. It is for these reasons that the company, which has manufacturing facilities around the globe, has opted for cutting-tool support from MSC Industrial Supply Co.

At the Broughton manufacturing site in north Wales, Gardner Aerospace manufactures structural components for aerospace OEMs from a variety of material types. To ensure the most efficient production method, and that a cost-effective solution is integrated into the business, the Broughton facility has in the past 12 months instigated a working relationship with MSC. The introduction of MSC regional applications engineer Stuart Wiezniak to Gardner Aerospace was a decision based upon trust and reputation, with Wiezniak already yielding impressive results for the company at its Hull manufacturing facility.
The new working relationship almost instantly yielded several cost savings and productivity gains as soon as he entered the Broughton site. With MSC’s decades of industry expertise, Wiezniak was recently introduced to a troublesome component that, with an annual production output quantity of 7920, was tying up a turning centre for much of its daily three-shift operation.

The S98 stainless rod-end component with a 30 mm diameter sphere required a considerable material removal rate (MRR) to create a flat on each side in a cost-effective cycle time. However, using the turning centre, the limited rigidity of the Y-axis milling head and the three-jaw chuck clamping set-up created frequent machine alarms and stopped production. To eliminate this error, free-up machine availability, reduce cycle times and cut tooling costs, Wiezniak worked with Gardner to move the process to a Dah Lih four-axis machining centre with a BT40 spindle taper, in the process helping develop a fixture that can hold five parts in a single set-up. The results are reported to be little short of staggering.

The previous set up on the turning centre utilised a 16 mm diameter ball-nose end mill with two indexable inserts, each featuring two cutting edges. This end mill, supplied by one of the world’s leading cutting-tool manufacturers, ran at 3 mm depths of cut with a paltry MRR of 6.64 cm3/min and a feed rate of 246 mm/min. By recommending an alternate machine, a different work-holding configuration and more applicable cutting tools, Gardner Aerospace is now saving more than £37,500 per annum on this one job – and there is scope to bring about an even larger cost saving.

By designing and manufacturing a fixture to clamp and machine five parts simultaneously, and then having the insight to utilise the 4th-axis to rotate the components 180° to generate the flat on the opposite side of the sphere, Gardner is realising massive productivity gains. MSC has been integral in this process and in subsequently reducing manual intervention, increasing productivity and cutting costs.

From a tooling perspective, Wiezniak removed the previous indexable ball-nosed tool and replaced it with a Dormer Pramet 32 mm diameter high-feed end mill featuring five inserts (four edges per insert). Applying inserts with Dormer’s M6330 coating grade, the MSC expert increased the machining parameters beyond recognition. Running the new rough and semi-finish end mill at a 0.7 mm depth of cut and a cutting speed of 180 m/min, MRR leapt from 6.64 cm3/min to more than 50 cm3/min. This outcome reduced the cycle time from 5 minutes 49 seconds per part, to just over 33 seconds.

The strategy applied by Wiezniak utilises the Dormer end mill for the semi-finish process, completing the task with a larger 50 mm diameter button tool. Taking 26 seconds of rough machining with the Dormer end mill and a 7-second cycle with the finishing tool, the total 33-second cycle yields Gardner Aerospace a reduction of more than 5 minutes per part, a significant saving considering the annual quantities required.

Commenting upon the strategy, Wiezniak says: “The first challenge was to ensure machine availability to move the part from the turning centre to a machining centre. From there, we had the freedom to instigate process changes such as the five-part fixture for machining. Devising a platform for rigid machining was the foundation block and, once this was in place, we could look more closely at tooling strategies and subsequent savings.

“The beauty of creating partnerships with MSC is that we have access to hundreds of vendors and more than 120,000 product lines, so we’re not constrained by a single-source tooling supply,” he continues. “As a result, we can ensure the best tool for the application. In this specific application, the Dormer Pramet 32 mm high-feed end mill was the optimal choice for high MRR. For the finishing cycle, the rod-end parts require an 8 mm radius on the flats, so we opted for a 50 mm button tool with four inserts, each with four cutting edges. Running at a feed rate of 622 mm/min with a single finishing pass of 0.1 mm depth of cut, the button tool delivers outstanding surface finishes with tool life of 400 parts per cutting edge.”

Summarising on the savings that have been made on the rod-end parts, Wiezniak says: “Cutting-tool strategies are always a balance of costs versus productivity rates. In this instance, the annual tooling cost increased by £321 per annum to £2678, but we have slashed machine hours by 81% from 724 hours to 141, while the cost per part has reduced from £28 to £23. The saving of £37,542 not only absorbs the slight increase in tooling costs, but improves process reliability, frees-up machine capacity and
man-hours, and enhances component quality. We have exceeded customer expectations with regards to meeting the original objective, while delivering the project goals on-time.”

Referring back to the “equally large cost reduction potential” on this job, Wiezniak adds: “The rod-end parts has two different part families within the 8000 quantity requirement. Some parts require a 24.8 mm diameter bore on the machined flat, while other parts need a 17.46 mm diameter bore. Before the COVID-19 pandemic and subsequent lockdown, we investigated the possible options, trialled several tools and the results already look impressive. However, although we can expect another huge leap in cost savings, we’ve not yet had the opportunity for final approval with these tools. When the opportunity arises, I’ll be certain to deliver even more fantastic results for Gardner Aerospace.”

For further information www.mscdirect.co.uk