Gloucester-based subcontractor Stratos Precision Engineering, a majority of whose business comes from machining plastics, has strengthened and diversified its turning department with the addition of its first sliding-head lathe, a Citizen Cincom L32-VIIILFV. The twin-spindle, 35mm capacity, bar-fed turn-milling centre has joined a plant list of five fixed-head, single-spindle chucking lathes for turning parts up to 650 mm in diameter.

Purchase of the seven-axis CNC Swiss-type lathe was part of an investment of more than £1m since the fourth quarter of 2018, which has also seen the arrival of a new big bore lathe and a 3 x 2 m automatic tool change CNC router, as well as refurbishment of the company’s 8000 sq ft premises in Gloucester. During the same period, the number of staff has doubled to 16, while in the last financial year, turnover increased by nearly 50% over the previous 12 months.
Stratos’ managing director Jonathan Caple says: “For some years we had been looking at buying a bar-fed lathe to increase our competitiveness, win new business and enter new industries by machining larger quantities of parts with tighter tolerances. We favoured the sliding-head type over fixed-head lathes, as the short axis movements lead to higher productivity. In addition, the twin-spindle configuration and extensive driven tooling on the machine means one-hit production often supersedes two or three operations on different machines.”
He adds: “To reap the full benefits of the investment, we need to be able to leave the machine running 24/7 either unattended or with reduced labour overnight to maximise production output. This was previously impossible due to the stringy swarf that is produced when machining plastic, which needs to be manually cleared by an operator on a regular basis.”
The situation continued until 2016, when Citizen invented and patented its LFV (low frequency vibration) software. Part of the operating system in the Mitsubishi control of Cincom machines, and switchable on and off if required during the program, LFV vibrates the servo axis in the cutting direction so that the tool tip leaves the surface of the material being machined for regular, ultra-brief periods.

The effect is to break the long strands of swarf normally generated when turning plastics into short lengths of just a few millimetres, preventing it from ‘birds-nesting’ in the machining area and melting back on to the workpiece, which normally means scrapping the part.
A recent trend in the subcontractor’s business has been a shift to machining more metals, notably aluminium for a large packaging machinery contract, but also ferrous metals such as stainless steel. This material also results in stringy swarf forming around the tool and workpiece, and therefore benefits greatly from using Citizen’s chip-breaking software.
Caple and Stratos’ co-owner, operations director Mark Vine, recognised how beneficial LFV technology would be for the business when turning plastics. Unlike metals, whose finish can be adjusted by fettling after machining, this is not practical with plastic as it needs to come off any machine tool in a finished condition.
The importance of improving turn-milling efficiency to increase competitiveness was reinforced when Stratos was required to produce 2000 parts over a short period and the existing machinery would only achieve 400 per day. However, with the new sliding-head machine and LFV technology, Stratos is now able to produce the 2000 parts in 48 hours.
It was a series of demonstrations at Citizen’s technical centre and showroom in Brierley Hill that decided the directors in favour of LFV over other chip-breaking methodologies which involve macros in the program. Additionally, as Caple points out, Cincom machines are built from the ground up to withstand the high-frequency, low-amplitude vibration caused by the intermittent, chip-generating cutting action.

The transition on the shop floor at Stratos to the new turning technology, as well as to the first Mitsubishi control on site, has been seamless. One of the sliding-head lathe operators, who normally runs five machining centres at the facility, quickly picked up programming of the L32 using Citizen’s Alkart CNC Wizard offline software. He and others received two days’ instruction at Brierley Hill, followed by a week of on-site operator training. In the period from machine installation in September 2019 to the end of January 2020, more than 30 jobs had been produced on the new lathe, which included some around-the-clock running.
A major benefit of a twin-spindle lathe is the ability to produce components machined at both ends in a single cycle that would otherwise require two separate operations. This capability is assisted by the availability of a multitude of tools, including driven cutters, which enable the inclusion of extra operations such as deburring, eliminating further subsequent processes.
Speed of production is consequently much higher on the bar-fed Citizen compared with the fixed-head chuckers. For example, a 400-off contract that used to take a full day is now finished in a couple of hours on the slider. Furthermore, Stratos can now manufacture in bulk, as the bar does not need to be changed as frequently as for multiple jobs. With this capability, Stratos can now run, say 1000-off, deliver 400 to the customer and stock the remainder on consignment. The customer benefits through more flexible supply and the certainty of prompt deliveries, while Stratos gains through more economical cost-per-part manufacture, which is passed on to the customer through improved rates and prices.

Another recent example of accelerated production was the machining of 5000 steel pins for a chain conveyor, which was completed in five days working a single shift. Previously, the job would have needed two operations on a pair of chuckers requiring two operators. Either the contract would not have been economical or the margin would have been unacceptably small.
Vine says: “The accuracy and surface finish we are achieving on the slider are fantastic. We recently ran the machine unattended around-the-clock with LFV, with coolant running to keep the temperature stable, and produced 3000 Ultem polyetherimide thermoplastic parts for a customer in the flow control sector. All of them were within the required -0/+0.05 mm tolerance band, which is impressive and can be difficult to achieve in this material without having to make adjustments to the machine.
“Overall, our new machinery has enabled us to be a more competitive subcontractor for plastic and metal machining, and is contributing towards the impressive growth of our business,” he concludes.
For further information www.citizenmachinery.co.uk

A fundamental change to the way stainless steel pump bodies are machined by subcontractor Metaltech Precision Engineers is resulting in far-reaching benefits. The advantages include a reduction in set-up time that lowers economical batch size by a factor of four, shorter lead-times, faster cycles, savings in the cost of tooling, and less wear on the machine tool.

Additional gains associated with the new production route are reductions in power consumption and in space taken up on the shop floor. Both are in short supply at the firm’s Hailsham factory and were the main drivers of the company’s desire to find an alternative manufacturing process.
High-value 500 mm or 630 mm twin-pallet, 50-taper horizontal machining centres (HMCs) with box ways and high spindle torque, of which there are nine on site, together with CNC lathes, have underpinned pump body production since the company was established in 1976. The components are typically produced in five operations on three machines.
A 40-taper, five-axis vertical-spindle machining centre, a German-built Spinner U-620 without a pallet changer supplied as a turnkey package by sole UK agent Whitehouse Machine Tools, now machines the components in two operations. Installed and operational within one week during November 2019, the cell heralds a progression at Metaltech from the use of raw power to smart machining methodology.
The pump bodies in question, of which there are eight types ranging in diameter from 160 to 280 mm with numerous different port details, are produced for a customer in batches of 50 to 60 to a monthly schedule that might include as many as 15 component variants. Sometimes orders were impossible to fulfil and discussions had to take place regarding alterations to the schedule, largely because the traditional machining process takes 10 to 15 hours to set up. After skimming the back face of a 316 stainless steel casting, the process involves roughing the same face on an HMC, and then roughing the front face, bores and ports on the same machine. The part is transferred to a lathe to turn the port details using single-tip boring bars, before returning to a HMC to re-skim either the front or back face so that a location can be provided for mounting the part on a window fixture upon which the finish-machining of both faces takes place. Producing of a batch of 50 to 60 bodies takes four weeks by this method.

In contrast, set-up on the Spinner takes just one hour and the new process route is completed in two set-ups, which means that 10- to 15-off can be produced economically. In the first operation, roughing and finishing of the back face and the interpolated bores are carried out by 16 mm diameter, solid-carbide end mills from MA Ford.
A Schunk pneumatic zero-point fixturing system presents the part to the spindle for the second operation in a time that rivals the speed of an automatic pallet changer. Then, a probe double-checks the datum and that the bores machined in the first operation are the correct size. Face mills complete the rough and finish machining on the front of the pump body. The savings offered by this method of production sees all 50 to 60 bodies completed in one week, rather than four.
Metaltech’s managing director Doug Murphy says: “We sent drawings to Whitehouse and they came back with set-up and cycle times on the Spinner that looked really good, which was largely down to producing the bores by circular interpolation milling instead of single-point turning on a separate lathe.
“We were worried that it would be difficult to hold the required 20 µm diameter tolerance using this method,” he continues. “However, our fears were allayed by a set of three cutting trials the supplier carried out in its Kenilworth showroom. We checked the bores on our CMM for size, ovality and taper, and they were within microns.”
Technical director Mick Bignell adds: “Another concern we had was that the new method of roughing and finishing the back face completely before turning the part over to machine the front face and outside would put stress into the casting, causing distortion and movement of the datums. This also proved to be unfounded.
“We had to look carefully at the surface finish of the internals and bores, as these rotary lobe pumps are used in the food industry and any roughness could cause hygiene problems. External finish is also important to our customer, as the polished appearance is a sales advantage. The interpolation milling cycles established by Whitehouse have proved to be equal to these requirements, producing a finish equivalent to single-point turning.”

Savings in tooling costs result from the new production method. The first thing to note is that on the HMCs, which use large indexable-insert cutters for roughing, the 60-station tool magazines are not big enough to accommodate all the cutters needed for every pump variant. On the Spinner, with the new process allowing commonality of tooling, the 32 pockets are sufficient to machine the complete range.
Using a waveform rough milling strategy with the 16 mm diameter cutter at high speeds and feeds, typically 2700 rpm and 2400 mm/min, rapid metal removal rates are achieved without unduly heating and stressing the part, helping to maintain accuracy. It is largely this lighter machining that allows the BT40 vertical-spindle machine to attain the same level of precision as a 50-taper HMC when cutting tough stainless steel.
Tool life is very good, according to Bignell. He says that one 16 mm end mill can rough 22 pump bodies, while a finishing end mill had completed 50 parts and was halfway through the next batch at the time of interview. A further benefit of these £120 solid-carbide cutters is that two or three regrinds are possible at a cost of £25 per time. Overall, the lower cost of tooling represents a monetary saving that Bignell describes as “immense”.
A further economy derives from reduced power consumption. The Spinner draws between 10 and 20 A current, whereas an HMC pulls 30 to 40 A. Murphy estimates that overall electricity usage will fall by two-thirds using the new pump body manufacturing process.
He concludes: “As demand for these pumps is continually rising, finding more efficient ways of manufacture is imperative. The reduction in set-up time from as much as 15 hours to one is a big game-changer with the Spinner, as is the elimination of work-in-progress.
“The process has lowered the economical batch size and is helping not only to increase flexibility of production but to reduce cost,” he continues. “Furthermore, by handling the parts fewer times, there is less risk of scrap. The customer also benefits, as they are able to reduce stocks levels.
“The ability of Whitehouse to turnkey this installation successfully has given us a path to expansion that was difficult to see before. We were out of space and out of power here in Hailsham, and the high cost of relocation was not an option. The Spinner U-620 requires half the floor space of an HMC and one-third of the power.
For further information www.wmtcnc.com

Extraordinary times call for extraordinary suppliers and, luckily for Birmingham-based CNC Routing, the company has a long-standing relationship with Industrial Tooling Corporation (ITC). With the COVID-19 pandemic taking a firm grip on the nation, UK manufacturers like CNC Routing are stepping up to support the NHS and critical infrastructure projects.

Founded in 2005, the company has an established position serving the automotive, retail, healthcare and industrial sectors with its design, routing, finishing, fabrication, installation and building services. The company has three AXYZ routing machines, each having a twin-head facility. So, when a customer became overrun with the production of critical ‘sneeze screens’ for supermarkets, the 26-employee business immediately stepped-up to help the cause.
Discussing the sneeze screen project, head of design and technical at CNC Routing, Chris Noble, says: “Just a week ago we were commissioned to manufacture 8000 acrylic, PETG and polycarbonate sneeze screens for supermarket checkouts. Machined from 3050 x 2050 mm sheets, the screens are manufactured in two sizes of 600 mm wide by 750 mm high, and 750 mm wide by 1000 mm high, with panel thicknesses ranging from 3 to 6 mm. With the screens being supplied to more than a dozen supermarket chains, each with various till and checkout dimensions, the different sized screens require both hole position and dimensional variations. This has resulted in our company producing more than 12 different screen variants.”
As soon as the order arrived on the Friday, the company placed an order with ITC and tools were delivered the next morning (Saturday). Discussing why the company turned to cutting tools from ITC, Noble says: “We’ve been successfully working with ITC for over 12 years and they supply all the cutting tools for machining our plastic components. The service, support and technical advice is surpassed only by the quality of their tooling.

“The ability to supply 60 cutting tools on a Saturday morning as a next-day delivery service during the coronavirus pandemic speaks volumes for ITC and its service,” he adds. “But from a technical perspective, we were having problems some years ago with our cutting tools gripping parts and lifting thin sheets from the vacuum bed of the AXYZ machines during processing. ITC provided first-class technical support by investigating our existing tools, materials and cutting parameters, and subsequently supplying new tools and machining strategies that resolved our issues. Since then, we’ve had every confidence in ITC and their tools.”
Observing UK Government and WHO safe-working guidelines, CNC Routing has moved many of its office-based staff to homeworking, while the huge influx of work has also seen the company change from a two-shift to a three-shift pattern.
“As a business we are conscious of the health and safety of our staff, and all employees are provided with suitable PPE. By moving to 24-hour production with three shifts, our shop-floor staff levels are naturally reduced. Furthermore, each of our three AXYZ routing machines are 3 m apart, so our factory floor automatically exercises social distancing.”
From a production perspective, the company has one AXYZ router with bed dimensions of 4880 x 2635 mm, while two further machines have a slightly smaller bed. This allows CNC Routing to place four 8 x 4’ sheets on the machine bed at any one time.
“The large machine beds allow us to set up four parts at a time,” explains Noble. “Additionally, each router incorporates a twin cutting head, which we can set at different widths. For the sneeze screens, we have spaced the cutting heads at a distance of 1230 mm apart, so we can cut two sheets simultaneously. With three twin-spindle routers running 24 hours a day, the performance and reliability of the ITC solid-carbide routing tools is essential.”
Initially, CNC Routing placed an order for 60 Clearcut series single-flute routers (6 mm diameter) from ITC. Commenting upon the tools, Noble says: “From experience, we know that these tools perform really well, have exceptional tool life and, with the upward spiral flute geometry, are perfect for machining thin sheets without lifting from the vacuum bed. This confidence in the 180 Clearcut series has been confirmed, as we’ve run the tools at 24,000 rpm up to the full 6 mm depth of cut at cutting speeds of 7 m/min. These machining parameters are beyond the recommended cutting conditions, but extraordinary times call for extraordinary measures. Luckily, the quality of the ITC Clearcut series can handle the increased speeds and feeds with ease.

“Despite running at significantly increased machining parameters, the 6 mm diameter cutters can comfortably process more than 50 sheets before we have to change the tool,” he continues. “After 50 sheets, the cutting performance and edge finishes are as good as they are on the very first sheet that we cut with a new tool. The only reason we change the tools after machining 50 sheets is because the protective film over the acrylic, PETG and polycarbonate sneeze screen sheets begins to fray slightly and ‘fluff up’.”
Nobody has a crystal ball, especially during a pandemic that is likely to change the face of UK manufacturing. However, CNC Routing is in a somewhat envious position compared with most manufacturers. The company has already manufactured 8000 sneeze screens in a week and has another 8000 to produce imminently.
Says Noble: “We are currently in the process of machining sneeze screens for supermarkets and, as the longevity of this situation continues and ‘non-essential’ retail companies re-open their doors for business, we expect to be making these sheets for everything from pharmacies and hardware stores to pet stores and other retail outlets. Added to this, we also have a strong order book with the healthcare sector for furniture, storage units and lockers that has to be fulfilled imminently. As a business, we’re very lucky that we can give all of our routing capacity to these essential services. We can do this as our regular retail work is naturally ‘on pause’. However, regardless of whether we are making sneeze screens, furniture or storage units for the health service, we know that we can rely on specialist cutting tools from ITC, even during a crisis.”
For further information www.itc-ltd.co.uk

Mould maker Kavia Tooling is using a Hexagon co-ordinate measuring machine (CMM) to create an offline zero transfer system ahead of the manufacturing process for parts and electrodes. This strategy considerably reduces downtime on its CNC and EDM machines when setting up new jobs.

Production director Mark Cole says some components are particularly time-consuming to set up traditionally, and even simple parts mean the machines are idle during set up. However, Kavia’s unusual use of the Hexagon CMM means that machines are cutting one job while the set up for the next one is being carried out.
“Hexagon customised their PC-DMIS software, which comes as standard on their measurement devices, to enable us to use it to find offsets at the beginning of the operation,” says Cole. “Instead of having to put each part on the machine and then set it, we set it on the CMM, which gives us the X, Y, Z and U orientation. We only have to put the zero transfer plate, which is micron-accurate, into position on the machine, and it knows the exact location of the part.”
This approach can be done with any number of components, thanks to another piece of customised software that Kavia Tooling devised itself, and which engineers from its CAM system, Edgecam, developed for the company. Edgecam drives seven high-speed CNC milling machines with spindle speeds varying from 12,000 to 30,000 rpm, and a Sodick EDM machine.
“But it’s no ordinary machining process thanks to the customised software which we call Merge,” explains Cole. “It collates data from all programs for the job and merges them into a single file, many at 36 MB and containing around 1.5 million lines of code. Merge also includes the Edgecam NC code, datums to set the parts on, zero transfer, and cutter tool heights.”
He cites an 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.”

Merge also keeps cutting tools to a minimum, by looking at information such as duplication, length and quality of the tools in all programs.
“If there are two repeating cutting tools in the individually merged program, it selects the best one for the manufacturing process,” says Cole. “It goes through every single NC program and rearranges all the tools accordingly.”
The end result of using Merge with the zero transfer fixture plates created on the CMM is a CNC program which can machine several parts at a time without the need to use the machine as a set-up station, as all preparatory operations are carried out offline.
Says Cole: “If we were setting up a component to be square, directly on the CNC machine tool without the CMM, we’d have to ensure it was perfectly in line with the machine’s axis. Doing that for 10 components considerably increases the risk of error, especially where there are overhangs. In contrast, setting them on the CMM means everything is automatically correct, because it tells the machine the angle of each part.
“To set up six fairly difficult components directly on the machine may take one day, during which time it’s not running,” he adds. “However, it’ll only take about an hour on the CMM, and we can be confident that they’ll all be absolutely accurate.”
Cole says that while the Merge software combines with the CMM zero transfer system to get the best out of the company’s CNC mills, even greater benefits are gained from using it on the Sodick EDM machine.

“This machine used to be our biggest bottleneck,” reveals Cole. “We had to set the electrodes and the part on the machine, and program it by typing-in figures manually, which led to errors. It was an absolute nightmare. However, when we developed the Merge software it went from being the largest bottleneck to the fastest machine in the factory. And it’s all mistake-proof; there’s no typing as everything’s done from the CAD dimensionally. Moreover, all the offsets are set on the CMM so there’s no setting on the machine.”
Merge collates all the programs, zero transfers and information about the spark positioning. The software works with up to 12 electrodes at a time; brings all the CNC programs together; identifies the X, Y, Z and U orientation; puts everything in a format that runs on the Sodick EDM to the correct datum; automatically adjusts the tank height; and provides a setting sheet.
In fact, Merge is proving to be so beneficial for both simplifying and accelerating the work on the Sodick EDM that Kavia is now developing the software commercially for those machines.
“It’s currently being trialled in the field, and we’re aiming to start marketing it shortly,” confirms Cole.
For further information www.edgecam.com

Hertford-based Qualiturn Products is a good example of the productivity increases that can be achieved by the application of advanced IT systems, the use of high-yield machine tools and the adoption of the latest automation technology. In addition to performing daytime manufacturing, the firm’s highly efficient working practices allow it to operate ‘lights out’ each night.

Qualiturn has achieved a genuine ‘virtuous circle’. The company’s application of advanced manufacturing techniques has enabled it to realise world-class levels of production efficiency. These efficiencies have allowed Qualiturn to supply competitive quotes that have resulted in further profitable business. And the profits generated have supported additional investments in ever more advanced manufacturing technologies.
In addition to earning a reputation for efficiency, another important aspect of Qualiturn’s values can be found in the company’s title. Qualiturn’s quality philosophy is reflected in all aspects of its activities. Although, as often happens to businesses that achieve substantial upturns in production, the increased amount of Qualiturn parts needing final inspection, began to place a strain on the company’s quality control provision.
To ensure the continued efficient operation of its inspection department, Qualiturn’s managing director Nick Groom recently undertook a search for a CMM that had a precision specification that would enable the inspection of parts with demanding dimensional tolerances. Also, given the high volumes of components that need to be inspected, a fast-operating, CNC-driven machine with a granite table that could accommodate multiple components, was required.
Having studied the available alternatives, Groom purchased a 500 x 700 x 400 mm capacity version of Mitutoyo’s recently launched Crysta Apex V-series CMM. As a result of increased acceleration, faster travel and improved accuracy specifications, the latest Crysta Apex V-series CMMs are able to accomplish significantly more component measuring cycles in each working day, and deliver higher levels of precision.

Explaining Qualiturn’s quality ethos and his recent Mitutoyo CMM purchase Groom says: “We are an ISO9001 registered business and we see efficiency and quality as the same thing. For instance, the right-first-time production of quality parts is efficient, whereas the manufacture of poor quality parts that require rework is inefficient.
“Having recently searched for a suitably accurate and fast-acting CMM, when compared with the alternatives, I was impressed with the abilities of Mitutoyo’s new Crysta Apex V-series machines and was happy to place an order,” he adds. “Now installed and up and running, our staff soon mastered the new CMM’s logical software and controls following a short operator training session. As well as having the levels of precision that allow the inspection of our most demanding parts, the Crysta Apex V-series CMM has the speed of operation that we need, and it has significantly increased our inspection efficiency levels.
“Now, prior to a production run, when writing a program for our machine tools, we use this model to also generate an inspection program for our Mitutoyo CMM. This means that when manufacturing commences, we can load the relevant program on to our CMM and quickly verify the first-off part. Then, throughout the production run, our quality staff are able to load large batches of parts on to the CMM’s bed and start a fully automated, unmanned inspection routine.
“The performance of our Mitutoyo Crysta Apex V-series CMM means that, not only has it satisfied our current inspection requirements, but it should also meet all of our future anticipated inspection needs.”
Drawing on its technological expertise in the field of CMM design and manufacture, Mitutoyo recently launched the Crysta Apex V-series. The new CMMs have a proven bridge-type construction, feature high-rigidity air-bearing guiding on every axis, and use Mitutoyo’s ABS scales.
As the successor to the previous generation of Crysta Apex CMMs, the new models build on the merits of their predecessors. In addition to boasting impressive accuracy specifications, the latest Mitutoyo models have rapid acceleration and fast speed characteristics. Not only do these qualities allow the inspection of components with challenging dimensional specifications, when compared with other lower specification machines, they increase business efficiency levels by enabling more components to be inspected in a given time.

Increasingly, companies are looking to measure parts closer to their means of manufacture. Therefore, besides being suitable for use in inspection departments, Crysta Apex V-series CMMs have a high level of resistance to environmental conditions and are at home in less than ideal production environments. Further aiding shop-floor use, the new CMMs are equipped with an automatic temperature compensation feature.
As a result of Mitutoyo’s flexible CMM concept, the Crysta Apex V-series represents a future-proof investment. In addition to handling users’ current inspection needs, the new CMMs are capable of adapting to future requirements thanks to the ability to change or add probe systems, accessories and software.
Given the advent of smart factories and the arrival of the IoT, the Crysta Apex V-series is equipped with Mitutoyo’s Smart Measuring System (SMS) technology. SMS allows the online monitoring of operational status and the capture of records related to key parts.
Moving forward, Mitutoyo will drive the installation of SMS technology, not only in CMMs, but in other CNC measuring instruments. Leveraging the IoT, the company will support the realisation of smart factories that conduct the sophisticated management of information relating to production and quality.
For further information www.mitutoyo.co.uk