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Chance purchase of a second-hand lathe triggers transformation of subcontractor’s machine shop

When a customer of subcontractor Apsley Precision Engineering suddenly stopped manufacturing components in-house, one of the redundant machine tools, a Miyano fixed-head, twin-spindle, single-turret lathe, was purchased by the contract machinist’s managing director, Peter Aymes.

Its arrival in 2012 on the shop floor at the company’s 12,000 sq ft facility in High Post, near Salisbury, heralded the start of a big improvement in CNC turning capability. Following the purchase of two more second-hand Miyanos, August this year (2019) saw the arrival from Citizen Machinery UK of the first new model, a BNJ-51SY twin-spindle, twin-turret lathe with a Y-axis.

Mr Aymes said, “We were aware of this make of bar auto and knew they rarely come onto the second-hand market, so we were lucky to be able to buy the first machine, a BND-51S twin-spindle lathe with live tooling in the turret.

“Compared with our single-spindle, bar-fed lathes without driven tools, it approximately halved cycle times for machining parts up to 51 mm diameter. Generally we were able to start producing components in one hit rather than two or three operations, reducing handling and work-in-progress.

“That in turn improved accuracy and allowed us to manufacture more cost-effectively, so we became more profitable. It is difficult to overstate the improvement the machine made.”

Another notable benefit was that an operator could set the Miyano and walk away for long periods to carry out other tasks, as it is unusual to have to change offsets owing to the consistency of machining. That is not the case with the subcontractor’s other bar autos, which tend to occupy an experienced setter for much of the time, raising the labour cost content of manufacture.

Based on all these advantages, a second Miyano BND arrived one year later. Purchased at auction, it turn-mills parts from bar up to 42 mm in diameter but is otherwise similarly specified to the first machine. Despite being 12 years old at the time, it was and still is capable of holding tolerances down to ± 5 microns, which Mr Aymes describes as “amazing”.

He continued, “By that time it was abundantly clear just how good these machines are. They are heavy, compact and very robust, which leads to high accuracy, repeatability and reliability. They need very little money spent on them for repair, so cost of ownership is low.

“It is rare to operate a machine that is almost completely trouble-free. With the Miyanos, that applies to the electronics and electrics as well as the mechanics.”

The third Miyano to be installed at the High Post factory, in 2015, was a second 42 mm machine of similar age acquired from another subcontractor, this time a BNJ model with two turrets. It was bought to cope with the increasing amount of work these machines were generating and to exploit the higher productivity possible due to the presence of a second turret to serve the sub-spindle while the other turret operates at the main spindle. It resulted in higher production output, better prices for customers and shorter delivery lead-times.

With a view to increasing production output still further, as well as to access the latest technology and provide back-up for the 51 mm capacity lathe, the subcontractor’s first new Miyano, a BNJ-51SY, was delivered in July 2019 by Citizen Machinery UK. As its designation implies, the machine has additional Y-axis movement on the main turret that is proving invaluable for machining off-centreline and providing flexibility and accuracy of milled features.

Mr Aymes cited one component that is produced much more efficiently with this feature. It is a tubular, thin-wall aerospace part machined from solid 304 stainless steel bar of 38 mm diameter. It requires a blind, longitudinal hole to be drilled and bored and the outside diameter (OD) to be turned to leave two lugs. Not only does the Y-axis allow the lugs to be drilled in-cycle, instead of the component having to visit a machining centre for completion, but by being able to program both Y-and C-axis movements into the OD turning, cutter deflection is minimised and accuracy is improved. As the component is required in batch sizes ranging from 200 to 800, the benefit is considerable.

Even more advantageous with the new machine, however, is the ability to take advantage of ghost-shift running, which is theoretically possible with the other Miyanos but practically not feasible due to the absence of load monitoring to detect worn or broken tools and automatically stop the machine.

The latest lathe, with its fail-safe features and reliability, is regularly left to operate unattended overnight. So also is a multi-pallet, 5-axis machining centre added to Apsley’s prismatic machining department in April 2018. Mr Aymes predicts that these two machines will pay for themselves faster than all the others on the shop floor. He asserts that if a production centre is capable of running lights-out and is of the right quality, rapid amortisation renders the initial purchase price much less important.

When Citizen installed the latest lathe, it also supplied the subcontractor with the latest version of its Alkart CNC Wizard programming software. It assists and simplifies the creation of even complex cycles using a built-in G-code and M-code library plus reference material and diagrams. Inexperienced users in particular benefit, such as Apsley’s Jay Pritchard, who is halfway through a four-year mechanical engineering apprenticeship. He said he finds the wizard useful when operating the new Miyano if his mentor is not available and the relevant manuals are not to hand. It also helps with understanding how to use the machine.

Founded in 1984 by Peter Aymes’ father Graham, the subcontract engineering firm has always split its machining approximately half and half between turning and milling. Key sectors supplied with high tolerance, complex parts and assemblies are aerospace, defence, medical and pharmaceutical. Non-kanban batch size is typically in the range 20 to the low hundreds and the company also operates a toolroom facility for smaller batch runs, prototype production and the manufacture of tooling and fixtures.

However, one-third of the company’s business derives from supply of components and assemblies just-in-time, providing price stability through the ability of the subcontractor to produce much larger quantities for consignment stock, with customer call-off typically at a rate of 1,000 pieces per week.

TWIN-SPINDLE TWIN-TURRET LATHES ARE IDEAL FOR HYDRAULIC COMPONENT PRODUCTION

A second pair of Miyano BNE-51MSY turn-mill centres from Citizen Machinery UK has been installed at contract machinists Unicut Precision, Welwyn Garden City. Joining two identical twin-spindle, twin-turret lathes with live tooling and a Y-axis on the upper turret supplied at the end of 2017, they form the mainstay of highly efficient production of complex components for the hydraulics industry, which accounts for a large proportion of Unicut’s business.

Established in 1990 by 24-year-old Jason Nicholson and a partner, who has since left the company, in a double garage in East Barnet with £5,000 to spend on second-hand manual and cam-controlled machines, Unicut has been a turned parts subcontractor for most of its existence, progressing to CNC turning in 1993. However, in 2017 the company diversified into prismatic machining with the purchase of a multi-pallet machining cell, followed quickly by a second. A third cell is now on order for delivery later in 2019, which will be a record year for capital investment at £2.3 million.

Over the years, Mr Nicholson has bought 104 CNC lathes, 93 of which were either Citizen Cincom sliding-head models or fixed-head lathes from Miyano, which merged with Citizen in 2011. Today, Unicut operates 22 Cincom lathes with up to 13 CNC axes, 80 cutting tools and 2,000 psi coolant pressure, as well as eight Miyano machines deploying up to 72 cutters. The machines are usually replaced every five to seven years to take advantage of the high residual value of the lathes at that age.

While turning machines have been sourced mainly from this supplier, each purchase is rigorously analysed by Mr Nicholson with respect to machine cost and achievable cycle times to ensure lowest cost per part produced and the most rapid return on investment. Ease of machine integration and use and the desired quality of component are also paramount considerations. Additionally, prompt provision of service is an important deciding factor.

1999 saw the first Cincom sliding-head lathe delivered to Unicut, a 12 mm bar auto, and within a year three more were installed followed three months later by a 32 mm model. The first Miyano appeared on the shop floor in 2002. The CNC lathes replaced cam-controlled turning machines, which had all gone by 2003. CNC equipment was by then achieving similar cycle times to cam-type lathes, with the added advantages of higher quality and unattended running including overnight, leading to much higher profitability.

To distinguish Unicut from other subcontractors, Mr Nicholson decided early on to adopt a different business model by approaching OEMs, analysing their main cost drivers, investigating the possibility of re-engineering components for more efficient production, establishing desired cycle times, identifying machine tools needed to machine components within those times and then proposing to make the required capital investments, subject to the manufacturer’s commitment to a fixed-term contract. Strategic supplier status is what Unicut seeks in its business relationships with customers and 80 per cent of throughput at the Welwyn Garden City factory is produced on this basis.

For machining larger diameter parts, a 51 mm capacity Miyano costs about the same as a top-end 32 mm Cincom slider. Unless a high component length-to-diameter ratio dictates otherwise, Mr Nicholson prefers the fixed-head option based on a number of factors including rigidity, thermal stability, value for money and speed. Bar capacity is greater, offering more flexibility; spindle power is higher, leading to increased productivity; cycle times are comparable; access is easy for setting up, despite the compact machining area; and the Mitsubishi control supports superimposed machining whereby three tools can be in cut at the same time, a facility regularly used at the Welwyn Garden City facility for elevated levels of productivity.

Once a BNE-51MSY is set, Mr Nicolson said that it will produce a run of say 1,000 components to very high accuracy without having to touch the machine by the simple expedient of including macros in the program to offset tools automatically after a predetermined number of parts have been produced. Tolerances down to ± 2 microns can be held and surface finish is described as impeccable. He favours the Mitsubishi CNC system fitted to Miyano and Cincom lathes due to its flexibility and ease of operation using the drop-down menus and comprehensive graphical support. Citizen’s off-line Alkart Wizard software helps to ensure jobs are quickly into production. However, for larger production runs, time can generally be cut from a cycle by tweaking the program at the control.

Citizen’s operating system in the CNC system fitted to one of Unicut’s Cincom sliders features patented LFV (low frequency vibration) software that operates in two CNC axes simultaneously, allowing stringy swarf to be broken into shorter chips of a length to suit the material being cut and the swarf conveyor. The feature is popular with operators, as it enables uninterrupted production without having to stop the lathe due to birds nests clogging the workpiece and tools.

Citing a 320 stainless steel part that was previously impossible to run unattended even during the day, yet is now routinely left to run lights-out with LFV, Mr Nicholson said, “The feature is easy to use and does not require any special skill set. The software can be switched on and off, either manually or within a program, and parameters can be adjusted. It is especially good for processing plastics unattended as well as other difficult-to-machine metals such as Duplex and titanium. It just works.”

In conclusion, he shared his thoughts on the current buoyancy of the subcontract machining sector due to the weakness of the pound against overseas currencies. It has cut 20 per cent off the price of components that Unicut exports and has boosted turnover, despite raw material and indeed the equipment on which to machine it being more expensive to buy. The firm’s first order from China was delivered in August this year and exports overall currently account for 40 per cent of turnover, up from 10 to 30 per cent in previous years.

BUYING A MACHINE TOOL? DISCUSS THE BUSINESS CASE.

Citizen Machinery UK’s open house on 1st and 2nd October 2019 focused on machine price and purchasing options. This article highlights some of the points of discussion with potential customers regarding flexible machine finance.

The head of Citizen Finance, John Lane, who has experience in accountancy, banking and selling capital equipment, is evangelical on the subject of establishing a business case before purchasing new machinery and asking if the potential investment is financially viable. He observes that the subject of money is often one of the last items to be discussed when it should be one of the first.

Mr Lane says, “Financial aspects should be discussed right from the outset. As soon as the Citizen sales engineer or technical department confirms that a component can be made on a particular Cincom CNC sliding-head lathe or Miyano fixed-head turning centre, I recommend that the conversation about money starts.”

The key questions are: how much do you sell the components for; how many do you have to make; and how long will it take to make them on the proposed new machine? From this information it is possible to calculate quickly and easily whether the profit to be made in manufacturing the parts on the machine will justify the investment. Once the numbers show that the customer is predicted to make money, Citizen Finance can provide a wealth of options that may not be available in high street banks. Mr Lane says finance companies that understand the manufacturing industry are best placed to offer specific solutions. Banks have a vital role to play but cannot be masters of all financing; one size does not fit all.

Underpinning offers of finance is the statistic that, after providing a 100 per cent loan, Citizen Finance’s fund providers (selected banks, finance houses, etc), due to the high residual value of Cincom and Miyano lathes, carry a risk significantly lower than it would otherwise be. Even after five years, a typical Citizen lathe still has a sales value of almost two-thirds of its price when new. It has been known for a 10-year-old machine to sell for 45 per cent of its original value.

So what funding mechanisms are available for machine acquisition, bearing in mind that nine out of 10 lathes purchased from Citizen Machinery UK are financed? Mr Lane advises that there are four main options: hire purchase, finance lease, operating lease, and loan-and-charge.

Hire purchase means the user receives the capital allowance, makes fixed monthly payments normally over five years and owns the machine. A finance lease requires similar payments but machine ownership remains with the financier, the user obtaining tax relief on the rentals. An operating lease is essentially rental, can be over any period, may be matched to a contract and a longer agreement can offer lower monthly repayments than ownership. The machine is returned to Citizen or the financier at the end of the agreement, an option that is becoming increasingly popular. Loan-and-charge is rather like taking out a mortgage on the machine, which the customer owns from the first day.

Citizen Finance aims to keep customers’ cash flow under control. Its deposit-finding scheme underpins the order with no impact on the customer’s cash resources and secures the transaction. On delivery of the machine, customers enter a pre-arranged finance agreement and therefore have a revenue stream from the investment whilst paying for it.

A rule of thumb for budgeting over five years is a monthly payment of two per cent of the capital sum per month. The date of sale can be timed to optimise the customer’s VAT position or Citizen Finance can support a VAT deferral. The current enhanced first year tax allowance means the first £1 million of money invested is fully tax deductible, a limit that will reduce to £250,000 from January 2021. Citizen Finance considers the customer’s tax position to calculate the most tax-efficient funding solution.

Mr Lane advises, “Some customers prefer to pay a deposit using their own money to reduce the monthly repayments. However, the more cash invested before one starts to earn can reduce the return on a company’s capital. Similarly, increasing the instalments to reduce the loan term may not lead to a better fiscal outcome.

“We have options. A Citizen Finance package can be tailored to a customer’s needs and there is considerable flexibility. We need to talk to every customer to understand what they require. Then we try to match our offer to those needs, long- or short-term, on or off balance sheet.”

Emphasising how successful this approach is, Mr Lane points to manufacturing companies that buy one turning centre, particularly of the sliding-head variety, run it many hours per day, reducing labour costs and increasing profitability, then often invest quickly in a second, third and more machines. Some continue the process, resulting in a low level of attended production, increasing the profit ratio and levelling the playing field between British and Irish manufacturers and those operating in low-wage economies.

A major part of Citizen Finance’s role is discussing the return a customer seeks to achieve from an investment. Different methods of funding will yield various returns on investment and payback periods. The impact on a company and the potential results are evaluated to try to make sure the returns are what the shareholders, directors or proprietors want.

To make this happen, Citizen’s cost per part software shows whether an investment will make financial sense. The following aspects are calculated, indicating the exhaustiveness of the analyses: machine cost per month, total manufacturing cost per component, hourly and monthly margin, months until cash positive, and return on investment percentage.

If a machine is fitted with Citizen’s patented LFV (low frequency vibration) function, which has the effect of breaking stringy swarf into manageable chips when turning stainless steel, copper and plastics, lathe uptime can be increased dramatically. It is a result of not having to repeatedly stop the spindle to clear swarf that has become entangled around the tool or workpiece. In such cases, the enhanced financial benefits can easily be calculated.

One Citizen Machinery customer advised, “The move into sliding-head technology was a large investment for us. We knew we were turning away business or subbing work out that we could have done in-house. However, the prices we needed to quote to machine some components led us to think we might not make money, as our experience was in conventional CNC turning.

“When we analysed the sale price of the components against the Citizen cycle time studies, things began to get a lot clearer. Citizen’s business analysis helped us calculate our investment justification and we proceeded on the basis that this would yield us a good return. The reality met the expectation. Within a year we had a second machine and over the following years we bought eight in total.

“We felt it was important to review our business investments and in so doing, we found that the Citizen machines accounted for 40 per cent of our capital investment budget, 60 per cent of our turnover and 80 per cent of our profit!”

CITIZEN MACHINERY EMPLOYS NINE MORE STAFF IN THE UK

To satisfy the needs of its expanding customer base, Citizen Machinery UK has employed nine extra staff since the beginning of 2019, bringing the total number of employees to 58. Located at the company’s headquarters in Bushey and in the new turning centre of excellence in Brierley Hill, the new recruits have been selected to cover core functions within the operation, including applications engineering, machine service, software development and European sales.

Darren Wilkins, deputy managing director pointed out, “Sales of our Cincom sliding-head lathes and Miyano fixed-head turning centres in the UK and Ireland were at a record high last year at 164 machines. It made us the foremost supplier of CNC bar autos into those markets, while in the first quarter of 2019 we became the leading supplier of sliding-head lathes into the UK and the whole of Europe.

“It is essential we keep our headcount commensurate with the level of business, bearing in mind the UK is also the distribution hub for Citizen machines going into France, Spain, Portugal, Scandinavia, the Middle East and Africa, which accounts for three-quarters of unit sales.”

He added that the increased number of personnel, as well as the opening of the new Brierley Hill premises and the retention of another nearby building that was the former headquarters of Miyano, is a reflection of the emerging significance of Industry 4.0 and the greater number of turnkey installations Citizen is being asked to supply, complete with programs, tooling, accessories and frequently automation.

MACHINE TOOL COMPANY OPENS NEW CENTRE IN THE MIDLANDS

More than 150 people attended the official opening of Citizen Machinery UK’s new £3 million Turning Centre of Excellence on Hurst Business Park in Brierley Hill, West Midlands, on Monday 15 July 2019. It houses a showroom, international conference area, customer training school, applications engineering department and administrative offices. 

Visitors on the day comprised of the firm’s more than 50 UK employees including those from the headquarters in Bushey, company representatives from Japan and around Europe, dealers and supplier partners from Japan, France, Italy, Portugal, Scandinavia and Israel, and staff from the contractors that realised the difficult building job over disused coal mine shafts in just 26 weeks.

Deputy managing director Darren Wilkins delivered the first speech in the newly built, 680 m² showroom and technical centre extension. He said that with the demands of Industry 4.0 taking on added significance for the manufacturing sector, the new centre provides extra space for preparing high-value, automated turnkey installations complete with programs, tooling and accessories. He also thanked Dudley Council, which has been supportive throughout the project, and borough Mayor, Councillor David Stanley, for his attendance.

He then introduced the second speaker, the president of Citizen Machinery Japan, Mr Keiichi Nakajima. During his address he pointed out that sales of Citizen machines in Europe have increased year on year and in 2018 the region sold 1,200 units, taking turnover to nearly 600 million Euro, the highest ever. To put this into perspective, it meant that Europe achieved the group’s highest sales, even beating Japan where the headquarters is located. He also mentioned that Citizen is now market leader for sales of all fixed- and sliding-head bar turning autos in the UK and Ireland.

 

 

The full texts of both addresses are available to download at: www.therightimage.net/citizen.html

After the presentations, Mr Nakajima cut a ribbon formally opening the new centre. He then planted a cherry tree in the grounds of the 1.1 acre site as a traditional symbol of Japanese culture and a lasting reminder of the strong bonds between Japan and the UK.

NEW SLIDING-HEAD LATHE TAILORED TO MEDICAL COMPONENT PRODUCTION

On the occasion of Citizen Machinery UK’s official opening of its Turning Centre of Excellence in Brierley Hill on 15th July, the company launched a new CNC sliding-head lathe, the 12 mm bar capacity Cincom L12 Type X. It is intended primarily for production of dental abutments and implants, but is also well suited to manufacturing parts for the medical industry in general.

For efficient abutment machining, a minimum of five rear-facing endworking tool positions including driven stations are required, as well as the addition of a Y2-axis to the X2 and Z2 movements on the counter spindle to match the three degrees of freedom on the main spindle. All these prerequisites are provided on the L12-X. Previously, to obtain this level of functionality, a user would have had to purchase a 16 mm or even 20 mm capacity lathe, unnecessarily large and expensive for production of such slender components.

Citizen’s patented LFV (low frequency vibration) chipbreaking software in the control is optional and recommended for machining the exotic materials prevalent in dental and medical applications. By vibrating the X and Z servo axes in the direction of cutting in synchrony with rotation of the spindle, problems arising from stringy swarf entangling around the workpiece and tool are avoided. The function, which now has three modes, may be used with static and driven tools. It is especially helpful when grooving, drilling deep, small diameter holes, and most recently also for internal and external thread cutting.

A modular tooling system has been adopted for the gang and back tool posts and an extensive variety of tooling layouts is possible, which includes the ability to drill angled holes. The maximum number of tools that can be deployed is 38.

Unlike on other Cincom L12 models, a built-in 12,000 rpm motor drives the counter spindle, reducing acc/dec times for higher productivity. Rapid traverse in all axes of 35 m/min contributes further to minimising idle times. The new machine is also wider, providing better access to the working area. Rigidity of construction is evidenced by the 2.2 tonnes installed weight and the footprint is compact at 1.84 by 0.97 metres.

CITIZEN’S NEW 32 mm SLIDING-HEAD LATHES HAVE LOW FREQUENCY VIBRATION SOFTWARE

Two new sliding-headstock, twin-spindle, turn-milling centres of 32 mm bar capacity have been added to Citizen Machinery’s Cincom programme. Designated L32-X LFV and L32-XII LFV, both feature the firm’s patented, low frequency vibration software in the control’s operating system that acts in two axes to convert what would normally be long, stringy swarf into short, more manageable chips. It is particularly helpful when machining stainless steels, plastics and copper and can be applied not only to turning but also to grooving, thread cutting and drilling.

Unlike the two other L32 bar autos in the range, the 8-axis L32-X adds a Y2 axis to the Z2 axis on the back tool post. So also does the 9-axis L32-XII, which additionally has +90 / -45 degree B-axis swivel on the front gang tool post, whose rotary tools can work at either spindle to produce angled holes. Both machines are available in 35 mm and 38 mm bar diameter versions and all may be used with or without the guide bush to suit the application.

The new L32 design is modular, enabling a user to optimise their manufacturing costs by selecting functions that achieve the ideal machine configuration for their needs, while retaining the option of being able to add extra functionality later. A workpiece conveyor is standard equipment. Control is by the Industry 4.0-ready Mitsubishi 800 CNC system, which allows up to three tools to be in cut at the same time.

Up to 44 tools for front, back and cross machining are available in the -X model, while the B-axis -XII version accepts four fewer. Speed range of the 3.7 / 7.5 kW main spindle and 2.2 / 3.7 kW counter spindle is up to 8,000 rpm. Both have a C-axis for use in conjunction with driven tool stations in the three tool carriers. Fast acceleration of tool rotation up to 6,000 rpm minimises cycle times. Rapid traverse in the linear axes is 32 m/min except in Y2, which moves at 24 m/min.

VERSATILE BAR AUTO IS HIGHLY PRODUCTIVE

A new, twin-spindle, 10-axis CNC turn-mill centre, the Miyano BNA-42GTY LFV, has been introduced by Citizen for manufacturing complex components in one hit from bar stock up to 42 mm diameter. The hybrid machine is of fixed-headstock design, but the head is also able to move in and out of the working area for extra versatility, similar to that offered by a sliding-head machine operated in non-guide bush mode.

The 8-station, 3-axis turret including Y-axis movement has a half-indexing mechanism that allows tools to be mounted at up to 16 positions, while multiple toolholders can further expand the number of cutters deployed. There is also Y-axis travel on a gang toolpost, giving extra flexibility when machining at either spindle, especially as the counter spindle moves in the X-axis as well as the Z-axis.

In total, up to 45 tools can be resident in the working area. A superimposition function within the Mitsubishi M730VS control provides the possibility for shortening cycle times even more by enabling up to three tools to be in cut simultaneously at both spindles.

The 3.74-tonne BNA-42GTY enjoys the same rigid, high precision build and thermo-symmetrical design as other lathes in the Miyano range, leading to high accuracy machining. Slideways are hand scraped in all axes and have exceptional damping characteristics, enabling heavy metal removal and helping to prolong tool life. Machine specification includes a 6000 rpm / 11 kW main spindle with 0.001° C-axis, a 5000 rpm / 5.5 kW C-axis counter spindle and feed rates up to 30 m/min.

Numerous options are available to add to the flexibility of the turning centre, including high-pressure coolant, spindle air blow, chip conveyor, parts catcher, parts conveyor and drill breakage detection. Likewise, the capable control can be augmented with the addition of helical interpolation, corner radiusing, synchronous tapping and multiple canned cycles.

The BNA-42GTY is the first Miyano machine to gain the benefit of Citizen’s LFV chipbreaking software, until now exclusively provided on the manufacturer’s Cincom Swiss-type lathes. The patented, two-axis chipbreaking functionality is part of the control’s operating system and involves the axis servo drives and spindle drives.

The position of the tool tip is oscillated by 20 microns, just sufficient to break the swarf. The number of oscillations per revolution (mode 1) or the number of revolutions per oscillation (mode 2) determines the length of the swarf removed from any type of material. The user can define the exact chip length in the program, giving the ability to choose the optimum size for the swarf conveyor to handle efficiently.

The more exotic and difficult to chip the material, the more effective LFV is. It means that high pressure coolant is not needed to assist in breaking long stringy swarf, such as that generated when machining such materials as stainless steel, copper and plastic. So it is no longer necessary to stop the cycle to remove accumulated swarf that is hampering the machining process. Shorter chips also take up less room in the swarf bin, so it needs emptying less frequently.

In some applications, particularly when processing exotic materials, productivity can be increased fivefold due to not having to stop the machine repeatedly to clear swarf that has entangled itself around the tool or workpiece, or both.

With LFV there is an element of air cutting, which allows more coolant to access the point of contact between the tool and the material. Enhanced coolant penetration lowers the operating temperature of the tip, so it can last five or even 10 times longer. This is especially the case if, as frequently occurs on other makes of CNC lathe, a chipbreaking macro has been written into the program. These are notorious for causing rubbing of the tool, built-up edge, machining inaccuracy and premature failure of the tip.

An LFV oscillation results in a turned face that is no longer flat by an amount measured in microns. The machine control knows where the oscillation took place and on the second revolution the high spot on the face is turned away. If required, on the third revolution the tool will finish that process to eliminate the waviness completely at that location.

As an element of air cutting – albeit miniscule – is introduced by LFV, productivity can be slightly reduced when the function is switched on. However, it can be turned off at the control, allowing the possibility of maximum output during attended day shifts when an operator is present to clear swarf. It may be, however, that these machine stoppages lower production output by more than LFV.

Switching the function on at night allows a ghost shift to be instigated without fear of swarf build-up automatically halting production during unattended running. So a manufacturer is virtually guaranteed a full shift’s worth of good components on arrival the next morning.

LATHE WILL PAY FOR ITSELF IN 18 MONTHS

Installation by Citizen Machinery of a fixed-head Miyano BNE-51MSY twin-spindle, twin-turret turning centre at electrical wiring conduit manufacturer ABB Cable Management Product, Coleshill, heralds a fundamental change in the way the company turn-mills its cable end fittings.

Cycle time savings of up to 70 per cent with more to come, reductions in manufacturing cost, scrap and returns, and elimination of the need to outsource 10 per cent of production to subcontractors will combine to amortise the cost of the Miyano well within 18 months of its installation at the beginning of January 2019. Manufacturing unit manager Andrew Fellows describes this payback time on a major item of capital expenditure as “brilliant”.

Every week, 100,000 metres of flexible metal conduit and 65,000 metres of nylon conduit find their way predominantly into the automotive, rail and mining industries across Europe, the Middle East, China and as far afield as Australia, while some are destined for installation in the parent group’s robot systems. From these numbers it is clear there is a high demand for the mainly brass fittings, plus some stainless steel, aluminium and plastic varieties, that are needed at both ends of every length of conduit.

Fittings needed in large volumes are produced in-house on six cam-type multi-spindle autos, while the shorter runs are completed on four single-spindle, single-turret CNC lathes and now the Miyano twin-spindle, twin-turret turning centre, which replaced a similarly specified, ageing model on which one of the turrets was defective.

Comparing the performance of the latter two lathes, Mr Fellows advised, “In the first two weeks of the Miyano arriving, we transferred onto the new machine the manufacture of four fast-moving products, all of which benefitted from drilling on both end faces simultaneously at the main and counter spindles.

“Average cycle time saving was 59 per cent. The largest reduction was 70 per cent in the case of a fitting that previously required 133 seconds to produce. The turn-mill cycle now takes 40 seconds to complete on the Miyano.”

Senior operator Dan Gardner added, “We have only taken advantage so far of cutting with two tools at a time, but the superimposition function in the Mitsubishi M730VS control, coupled with Y-axis movement of the upper turret and X-axis travel of the counter spindle, allows three tools to be in cut at the same time.

“After five days’ training from Citizen, both on- and off-site, we carried out a time study on a complex fitting that will see an 80 per cent reduction in cycle time from 230 to 46 seconds.”

He went on to describe a further benefit that comes from the ability to have 6,000 rpm live tools with 20 Nm of torque at all stations in both turrets, a total of 24 positions. Whereas 85 per cent of production on the single-spindle lathes is currently from hexagonal bar, the plan is to reduce this to zero in favour of round bar over the coming years as the machines are upgraded and powerful driven cutters are able to mill the flats economically. This process is starting with the Miyano.

The main advantage will be longer service life of the lathes and of the bar magazines feeding them due to the absence of interrupted cutting of hexagonal stock and hence lower vibration levels. In the case of the Miyano, it will also allow round bar at the full 51 mm diameter capacity to be rotated in both spindles at the maximum speed of 5,000 rpm, whereas it would need to be backed off by 75 per cent to run the largest possible size of hexagonal stock. For this reason, such material currently machined on the BNE-51MSY at Coleshill is restricted to 38 mm, which can be rotated at full speed.

Mr Gardner advised that despite utilising mainly hexagonal stock at present, the rigidity provided by the Miyano machine’s bed, hand-scraped box slideways, spindles and turrets is nevertheless sufficient to allow total tolerances down to 30 microns to be held on fittings, a level of accuracy needed for explosion-proof and watertight conduits.

Data collection and display on dashboards of overall equipment effectiveness has been instigated by Mr Fellows since his arrival at the factory in July 2018. Optimisation of every aspect of around-the-clock production has resulted in 24 per cent more output in five days than was achieved before in seven days, lowering manufacturing cost by 17 per cent and raising competitiveness.

Installation of the Miyano, with its elevated level of productivity, will improve these figures further. So also will the imminent arrival of a presetter for off-line tool setting, which will cut two-thirds to three-quarters off the present 60-minute changeover time for the next batch run, which can be as low as 50-off.

According to Mr Fellows, selection of the Citizen Miyano BNE-51MSY was down to the capital cost being 30 to 40 per cent less than two alternatives considered by ABB Cable Management Product, in line with company policy. Lead-time from order to delivery was also the shortest at just 12 weeks.

Megan McDonald Update

Just thought I would send you an update on what’s gone on since the launch day.

On Thursday 23rd of May I raced in the Ryton Pools 5mile road race. I had a really good race feeling strong throughout. I was able to win the race in 30.18s. This time shows my running has had a massive improvement over the winter. After looking at the power of 10. I have posted the 3rd fastest time for a U23 so far this year.

At the weekend I Raced in the British Super Series at Blenhiem palace.

My swim was never going to be anywhere near what it should be due to the nerve damage. I ended up coming out the water 1 minute down on the front girls.

The bike leg, all I could do was put my head down. I worked hard with a couple of girls and ended up coming into T2 in 1st. My Biking is feeling really strong at the moment.

On the run I was able to hold on to 4th, happy with the progress but still improvements to be made. My run time was 2 minutes faster than last year.

Thanks so much for all the support.

My next race is Two Castles 10km Road Race this weekend.

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