CAM plus automation is formula for success

At its 30,000 sq ft facility, Metri-Tech manufactures ultra-precision, high-volume components for the aerospace, medical, defence and commercial industries. Based in Huntington Beach, Metri-Tech Engineering is not a typical job shop – that much is evident from the company’s factory filled with automated production equipment, including a wall-mounted live scheduler, which resembles a 2 m tall iPad. Hans Gratzer Jr, COO/CTO of Metri-Tech and son of company founders Hans and Katharina Gratzer, developed the scheduling program to help his 38 employees better visualise what is happening in the shop at any given time and plan for the next jobs. This strategy is part of the company’s forward-thinking approach to automation.

“Most job scheduling systems are number-driven, but people like pictures,” Gratzer says. “With this system, what you see is what you get — kind of like Esprit.”
Metri-Tech has used Esprit CAM software almost since its inception; Gratzer estimates it was first installed in 1988.
“My dad bought the software, and he was very happy with it because we were mainly in the fitting business at that time; he liked that it could program families of parts,” he says. “It was a huge time saving.”
But just as crucial to Metri-Tech were Esprit’s accurate, full-colour simulations, which were said to be the first in the industry.
“That allowed us to give more visibility to our programming and reduce mistakes in our set-up the first time around,” says Gratzer. “Most of our machinists do both the set-up and the machine operation; they know what they’re doing. Now they do not have to worry during the set-up process and first-off run; they know the program will be right due to the precise nature of Esprit simulation, set-up sheets and posts.”
Some 30 years later, Esprit keeps Metri-Tech at the top of its game, thanks to its ease of use and quick support. The company uses the software for full five-axis contour composite milling, swarf milling and multi-axis multi-spindle turning.
“Esprit is very progressive in the five-axis and multi-axis realms,” Gratzer notes. “The software is just easier, faster, stronger and more accurate than other CAM programs we have tested or demonstrated over the years.”

At its plant, Metri-Tech machines all types of materials, including more exotic types like Inconel, titanium, Nitronic, Invar, Kovar, Ferrium, polyurethane, Teflon, PEEK and Ultem, to list but a few.
“Customers use us as a solution; they have problems and we fix them,” Gratzer says. “We’re experts in most manufacturing processes, and our customers come to us for
the precision and quality of part we produce.”
The company started out making fittings, which provided it with an understanding of how these parts fit into the larger assemblies. This comprehension allowed Metri-Tech to gradually move into more complicated parts.
“Doing fittings evolved into us going in the opposite direction: manufacturing the parts the fittings fit into, which were housings and manifolds,” says Gratzer. “Then obviously, when you get into the more complex and assembly side of medical and aerospace, you get into the critical finishes and close tolerances of the internal workings of the manifolds and housings, like spool and sleeve assemblies, and shaft work. It was a very interesting and methodical transition.”
The company operates 42 machines in total, with a number of three-axis Mori Seiki lathes and Nakamura-Tome lathes featuring up to 13 axes, which allow the company to be more creative with small parts. Metri-Tech also runs three and four-axis vertical mills, and several Matsuura five-axis vertical trunnion machines with up to 42 pallets and 520 tools.
In combination, Metri-Tech’s arsenal of machines provides programmers with hundreds of pallets and thousands of different tool options. Many of the shop’s palletised machines are automated, and the company is working to bring in mobile robots to transfer parts from machine to machine, along with virtual augmentation to help programmers easily view the custom manufacturing software and scheduler on the shop floor.
Metri-Tech, which boasts ISO AS9100D certification, offers polishing and ultra-critical finishes, as well as a high-end quality control facility in-house.
“What sets Metri-Tech apart from the competition is the quality when producing components in larger volumes,” says Gratzer. “Anybody can make a few good parts, but consistency and repeatability over larger volumes is the key to our success. Most customers say that quality is a given nowadays; it’s truly not. We take so many steps in assuring a quality part gets to the customer. We have a group of very dedicated employees, and everybody’s looking out for the quality of the product. The main reason why customers come to us is 100% quality, all the time. If they need a job done fast and they need it done right the first time, they come to us.”

Metri-Tech’s performance has been strong since its inception in 1978, but shortly after Gratzer came to work for the company in 1998, and with his vision for technology, automation and reinvestment, the company has experienced significant growth. Forecasts show that Metri-Tech may double its business within the near future.
“I credit the success to our passion for this industry; striving for automation and all the technology we use, including Esprit,” concludes Gratzer. “I feel our next 40 years are going to be stronger than the last 40.”
For further information www.espritcam.com

AMRC helps develop novel laser tracker

Engineers at the AMRC have helped develop a novel laser tracking measurement device that has the potential to be a disruptive technology in high-value manufacturing and a key capability in factories of the future.

A team at the University of Sheffield’s Advanced Manufacturing Research Centre (AMRC) believes Reflex Imaging’s Laser Metrology Module – LAMM for short – has the power to shake up the metrology market due to the low costs of the sensor it uses compared with more conventional metrology systems.
The sensor – which uses a laser to track a target and generate co-ordinates for that target – was originally developed for use in medical equipment. However, the AMRC saw the potential for the sensor to have multiple uses in high-value manufacturing. LAMM is still in development but the AMRC has helped Reflex Imaging develop the technology so that its functionality is suited to manufacturing applications.
This Catapult-funded collaborative project between Reflex Imaging and the AMRC’s Integrated Manufacturing Group (IMG) involved two workshops at the AMRC’s Factory 2050 to develop use cases and demonstrators for LAMM. The scope was to find application areas within the high-value manufacturing industry and help Reflex develop the sensor to suit these applications.
An initial workshop was staged to better understand LAMM and scope potential use cases. Basic demonstrator testing was also performed. A follow-up workshop was held after the development and prototyping phase focused on specific manufacturing tasks identified during the first session.
Large volume metrology technical lead for the IMG, Thomas Hodgson, oversaw the development work, and says possible applications identified for the technology include robotic tracking, fixture validation and robotic machining: “One of the uses of the trackers is for ensuring robotic drills are in the right place before drilling a hole, a task that is often performed with expensive equipment. The robot moves into position, before measurement and drilling takes place. The cost of the metrology devices that perform these measurements can be expensive, but we’ve worked with LAMM to show it can be done much cheaper.

“This technology exist already and is used widely in the aerospace industry because it allows for large scale measurements,” he adds. “For example, in order to certify a jig, you have to measure before you build anything on it because that’s how product quality is controlled. The trackers used to do this can cost anywhere up to £250,000. They are very expensive pieces of kit.
“The LAMM is novel in that the technology behind it makes it significantly cheaper than traditional laser tracking measurements.”
Reflex Imaging was set up in 2013 and is jointly owned by Peter Hart, chief executive officer, and Malcolm Humphrey, chief technical officer. Armed with their ideas and an early prototype of LAMM, the pair visited the European Portable Metrology Conference in Coventry last year to assess the market, and it is there they met representatives from the AMRC.
“As a start-up, we must use our scarce resources very efficiently, and having access to the experience, facilities and personnel of AMRC was to prove extremely valuable,” states Hart.
Those early discussions helped Hart and Humphrey identify the strongest potential applications and confidently set the focus for the company’s final hardware and software development.
“The ability to subsequently access working manufacturing cells at the AMRC and install our equipment to prove out the ideas was immensely valuable,” says Hart. “The conventional method of working with potential customers, with all their commercial pressures, would not have been as easy, nor, importantly, could we have done it in such a short time. Furthermore, in the AMRC we are working with not only today’s manufacturing challenges, but seeing manufacturing concepts for decades to come.”
Hart says that the future scope for LAMM technology is wide as it lets users achieve an order of magnitude improvement in precision over conventional systems for a given cost.

“LAMMs are designed to be simply connected together to achieve higher target coverage, higher sampling rates, higher averaging and system redundancy,” he explains. “The ability to use multiple, lower cost units opens up the potential of using laser-based metrology in applications that previously could not afford it, such as automatic calibration of robotic machine systems as standard. The factory of the future will use a scaleable network of integrated, precise, measuring devices.
“Above all the experience, information and facilities of the AMRC, one of the most valuable things coming from the project has been the strong personal confidence that AMRC individuals had in us throughout the project,” concludes Hart. “One year on at this year’s EPMC conference, our ideas have turned into a booth and products and applications, and the huge credibility that comes from the support of the AMRC.”
For further information www.reflex-imaging.com

Getting into gear with new mandrel

Hard work and first-class teamwork between gear manufacturer Hänel and Hainbuch has certainly paid-off. The new Mando G211 mandrel for gear manufacturers is particularly suitable for gear hobbing, cutting and grinding, and this has been demonstrated at Hänel. Now available as a standard mandrel from stock, this solution for gear cutting has optimised the manufacturing process, reduced set-up times and improved gear quality, largely credit to the stable clamping features that dampen vibration.

When a new product like the Mando G211 mandrel is launched, it must be tested thoroughly under real-world conditions. In this case, Hainbuch was looking for a reliable partner capable of testing a prototype, and the company approached Hänel GmbH & Co KG from Bad Friedrichshall, Germany.
Commenting on its willingness to participate, Jürgen Renner, the production manager at Hänel GmbH, says: “We already had positive experiences with Hainbuch clamping devices, so for us, the whole thing sounded promising from the very beginning. We saw the potential for improvements in our manufacturing and processes – that’s why we agreed. I must add, our management is very open to such partnerships and, if it results in rewarding optimisation and keeps investments manageable, nothing stands in the way of such a project.”
Hänel initially received two prototypes of the Mando G211 mandrel in sizes zero and two. The mandrels were tested on a Richardon R400 manual loading machine and a Gleason-Pfauter GP200 hobbing machine with automatic loading to see if they would be compatible.

“For our employees, this new clamping system was very strange, as for 20 years they worked with a clamping system from the machine manufacturer without radial clamping, which worked fine to date,“ admits Renner. “Initially, we had to make some adjustments to the machine and, in addition, we did not reach our zero-line on the Gleasen-Pfauter machine because the mandrel was too tall. As a result, adjustments to the machine and loading system were required. What followed were conversations with the responsible designers at Hainbuch. We have diligently tested and passed on all the information needed to further optimise the mandrel – all design changes were implemented by Hainbuch.”
The revised second prototypes were subsequently made available, undergoing field trials before a few minor adjustments to the machine were made. It was evident that the stiff and slender mandrel could go into series production and be produced for stock.

At Hänel, batch sizes are between 30 and 1000 pieces, which customers specify because of the precision. As a rule, the high-quality gears are hardened and ground, so reworking is not an option.
“With the current clamping system, we couldn‘t achieve good concentricity,” says Renner. “The workpiece was pressed axially downwards. Now it is clamped with the mandrel from the inside, radially outwards. Thus, we have higher clamping stability. This eliminates the reworking of certain components. For some of our orders, the old clamping system was good, because the concentricity was not so important. But basically, the better the concentricity, the easier it works later. With a normal hardened gear, the bore still needs to be reworked, but all the workpieces that are fully geared can now be reduced to one operation.”
Hänel has also improved set-up times with the new mandrel. This time reduction is because when using the Mando G211 mandrel, only the segmented clamping bushing and not the entire clamping system has to be changed. Use of the G211 also eliminates the need for alignment, which of course saves time. Even if the mandrel and segmented clamping bushing have to be changed to a different size, it is still faster. There are only three screws on the mandrel for the support and a screw on the segmented clamping bushing.
“If everything is prepared optimally, and the part family is in stock and can be processed one after the other, we will certainly save 50% of the set-up time,” says Renner. “Not only is the set up faster, but the process is more stable and safer.”
Andreas Hoffmann, head of toolmaking, sees even more benefits: “Thanks to better stability, we can drive higher feed rates. Even tool wear is reduced because we have less vibration.”
Hänel now has six Mando G211 mandrels, the two prototypes and four standard mandrels in sizes zero to four.

Hoffmann explains: “All new components have been manufactured with the mandrel ever since. Even with older components, we try to change over to the mandrel clamping because the segmented clamping bushings from Hainbuch can be delivered within one day. That’s a huge advantage for us.”
“For me, it is incomprehensible that we have not worked with Hainbuch before,” Renner concludes.
For further information www.hainbuch.com

Subcontractor progresses to five-axis machining

Craigavon-based subcontractor Boyce Precision Engineering primarily serves the commercial aerospace sector, which accounts for 70% of turnover. A majority of throughput involves producing aluminium parts for first-class and business-class seating, plus various aluminium structural components. Aerospace recognitions include AS9100 accreditation (the global quality management system for the aerospace industry), as well as supply chain recognition SC21 (Bronze Award) and ADS Group membership.

The contract machinist started operations in 2006 and in little more than a decade has made significant strides; the company now employs 34 staff. Earlier this year, Democratic Unionist Party MLA (Member of the Legislative Assembly) for the local Upper Bann constituency, Carla Lockhart, hosted a visit to the firm by party leader Arlene Foster and the chief executive of Invest Northern Ireland, Alistair Hamilton.
In recent years, there has been an increase in the complexity of the prismatic aerospace parts that Boyce Precision manufactures, making a progression from three-axis to five-axis machining necessary. For the new machining capacity, joint owners and brothers George and Brian Boyce decided to move away from the supplier of two-thirds of their three-axis machines. Instead, they opted for a 600 x 550 x 450 mm capacity, German-built Hermle C 250, which was supplied by sole UK and Ireland agent, Kingsbury.
The five-axis machine’s suitability was immediately apparent and a second, identical model has since been installed. The configuration of Hermle vertical machining centres places the three linear axes within a modified gantry above the working area, while the integrated trunnion provides a rigid, stable platform for the two rotary axes, which includes a ±115° swivel for production flexibility. The machines in Craigavon have integral Blum tool breakage detection to allow long periods of unattended running across the two shifts that Boyce Precision operates.
A further trend within the aircraft seating sector is towards larger components, which are even more complex to avoid the labour costs and delays associated with assembly. Once orders for such parts were promised, Boyce had no hesitation in placing an order for a larger Hermle C400 with a working volume of 850 x 700 x 500 mm.

The machine will be delivered in November 2018, directly to a new, 18,000 sq ft factory unit currently being built for the subcontractor in Portadown. Treble the size of the current premises, the building represents a £3m investment, taking into account the capital cost of the third Hermle five-axis machine and the imminent purchase of two further three-axis machining centres.
Boyce says: “As these are our first five-axis machines, ordering the initial one was a big decision. Our company policy is to buy the very best equipment we can afford, not only machines but also work holding, tooling and engineering software.
“We had extensively researched the five-axis vertical machining centre options, but before going ahead with Hermle I had a chance to see how the machines are manufactured at an open house at their factory in Gosheim, which gave me confidence in the build quality,” he adds. “Price and after sales support were also important considerations, and on both counts we felt confident in the Kingsbury offering. Their training of our skilled engineers on the shop floor was seamless, allowing them to pick up five-axis operation quickly.”
The benefits of five-axis machining to Boyce Precision are far-reaching. One-third of the time, the two Hermle C250s are executing programs requiring the interpolation of all five CNC axes simultaneously – work which formerly could not have been carried out.
To fulfil other contracts requiring only three-axis cycles, automatic positioning and clamping of the rotary axes reduces the number of separate operations needed to complete a job, in some cases dramatically. Aerospace parts that used to need two or three separate operations are now completed in one hit.
A pharmaceutical component that previously required eight separate set-ups now requires only two. This sector, together with medical engineering contracts, accounts for 20% of the subcontractor’s turnover, with the remaining 10% spread across automotive , motorsport, TT racing and general engineering. The latter work focuses on contracts for the construction industry, particularly bespoke jigs and fixtures, but also includes the manufacture of items for film sets, such as aluminium-bladed swords, daggers, shield parts and catapults used by actors in the television series, Game of Thrones.

The reduction in the number of set-ups also means that tight tolerances can be held more easily. On some aerospace parts, and even those for the pharmaceutical industry, such
as blister pack tooling, tolerances specified on the drawings are as tight as ± 20 µm.
Boyce says: “Hermle machines are inherently very accurate and able to hold this tolerance easily. The spindle in particular has no discernible run-out. Machine construction is very rigid, which not only ensures accuracy, but leads to longer tool life. The cachet of having Hermle equipment on your capacity list is not to be underestimated.”
He recounts an incident in January 2018 when the 18,000 rpm, HSK 63 spindle of the second Hermle C 250 was accidentally knocked out of alignment by an operator. Luckily, the machine has a patented safety feature in the spindle whereby six mounting bolts with collapsible sleeves crumple and absorb the energy just long enough for the shock to be detected, triggering automatic machine stoppage.
The spindle itself was undamaged and needed only to be remounted with six new bolts, which was done by one of Kingsbury’s local service engineers within a few hours the next working day. This process saved the expense of buying a new spindle cartridge and perhaps also the motor, as well as the costs of more major maintenance and extended machine downtime.
To ensure that there was no underlying spindle damage, vibration analysis files captured at different rotational speeds were sent by Kingsbury engineers to the Hermle factory for evaluation, where it was confirmed that the accident had not caused a spindle fault.
For further information www.kingsburyuk.com

Winning the tooling race at Tridan

In 2007, Tridan Engineering made a strategic decision to target prestigious aerospace contracts and steer away from commercial, agricultural and power-generation subcontract machining. In the past five years, the Clacton-based company has invested heavily in infrastructure, accreditations and machine tools, which has certainly paid dividends in achieving its goals.

Celebrating its 50th year in business, the subcontractor has spent more than £2.5m in the past two years on new acquisitions, including two Mazak Variaxis i500 machines (as well as an i600 and an i700), a Quick Turn 300 plus a Quick Turn 200MSY. Other recent investments include a six-station Palletech automation system and an additional three machines on order from XYZ.
The investment in high-specification four and five-axis machine tools, and the ever-expanding variety of materials being machined, has prompted a strategic overview of Tridan’s cutting tool strategy. In the two years since deciding to overhaul its tooling strategy, the AS9100-certified company has reduced its cutting tool suppliers from 14 to just two. From the 14 vendors, it is Industrial Tooling Corporation (ITC) that is driving innovation and cost reductions, and standardising cutting tools.
Discussing the logic behind consolidating its cutting tool vendors, Tridan Engineering’s senior production engineer Peter Townsend says: “When it came to cutting tools, our shop floor had no consistency or standardisation, and shop floor staff would order new tools from one of our suppliers as and when they needed them. To consolidate our suppliers, we firstly wanted to eliminate a few of the smaller vendors that couldn’t support our diverse demands. Once we did this, we started 18 months of trials with many of the internationally recognised tooling brands.
“During this process, we were going beyond trialling one vendor against another based on the usual parameters of tool life, performance and cost reductions,” he continues. “We were looking at the complete package: the service and technical support; the rapport between our engineers and the tooling representative; the diversity of the product portfolio; and of course, performance, consistency and cost were always key parameters. In fact, the arrival of a twin-pallet machine and a six-station pallet system means that reliable performance and longevity for lights-out running has become more prevalent than ever.”

During the trial period, ITC was fast emerging as the front runner to win the solid-carbide round tooling business from Tridan. This preference emerged from the relationship between ITC’s technical sales engineer Gary Bambrick and the Tridan engineers and shop-floor machinists. However, with tooling manufactured in Tamworth, it was the rapid turnaround on standard and special tools that also impressed Tridan.
Says Townsend: “We manufacture families of aluminium frame racks for the aerospace industry in batches of 10-off every couple of weeks. With a significant amount of material removal, we applied the ITC 49G9 series of ripper end mills with through-coolant and a trochoidal strategy that was recommended by Gary. This immediately reduced the cycle time from 6 hours to less than 5 hours, a 20% reduction.
“With these racks there are a number of thin walls that needed machining and the tools were pushing against the wall, generating different wall thicknesses and wavy surface finishes,” he adds. “Gary worked closely with us and ITC’s Tamworth headquarters to change tool geometries, edge preparation and corner radii on a 10 mm diameter 3081 series end mill that was used for finishing the thin wall profiles. This not only resolved our technical issue, it demonstrated the expertise and the level of support from ITC.”
With the arrival of the six-station Palletech system, Tridan is achieving upwards of 140 hours of production every week on its latest Mazak machining centre. Manufacturing titanium alloy enclosures for the aerospace sector, the cell has been producing 50 parts per week with a cycle time close
to 3 hours each.
The philosophy of this cell is to maximise machine utilisation and, using ITC’s solid-carbide VariMill end mill tools, Tridan was attaining four days of tool life from each end mill. To extend tool life further, Bambrick suggested a diamond-coated end mill. The result extended tool life from four days to seven, a 40% improvement. With 90% of tools in the cell being supplied by ITC, Bambrick is currently investigating additional opportunities.
Another special application that was causing tremendous difficulty was a nose cone for the defence industry. The titanium cone had a roughing cycle time of 45 minutes that ITC reduced to 25 minutes with a five-fluted ripper, a significant saving on a batch of 100 parts.
Following internal rough machining, the cone requires a series of slots and features, and the limited reach inside the cone caused tool vibration that was impacting upon tool life. The previous end mills were wearing out rapidly through vibration, typically after machining just three parts.
“With the combination of the challenging aluminium alloy material and extended reach requirement, the vibration being created was ruining cutters,” says Townsend. “Added to this, the slots have a 0.03 mm tolerance that we struggled to hit because of the vibration. ITC developed a 2.8 mm diameter extra-long end mill on a 12 mm shank that instantly eradicated the vibration, and improved surface finish and tool life. The new tool ensured we were easily within tolerance, while tool life went from one tool for every three parts, to five tools for the full batch of 100 parts. This gave us consistency, reliability, conformity and it meant we didn’t have to keep changing tools and checking parts. We have a number of ITC tools that have been running for weeks on this family of parts.

“Following the benefits of ITC tools in our production cell and the proven success of the VariMill 4777 series, we trialled the same VariMill roughing tool on a chassis part for the defence sector manufactured from S154 hardened steel (321HB),” he continues. “We were using a high-feed indexable end mill from another supplier and were burning out 2-3 insert edges on each part. Although this sounds like a high burn-out rate, the cycle time was 12 hours per part for each of the 30 components. Gary once again recommended the 4777 series and it slashed the cycle time from 12 hours to 3, and we managed to complete a full batch of 30 parts with just two end mills. This was a 70% cycle time reduction and a 90% tool life extension. We cannot credit Gary and ITC highly enough for the quality of their service and products.”
The tooling strategy at Tridan is continually evolving to suit the ever increasing material diversity and lights-out production requirements. Tridan has selected its two primary vendors based upon indexable and solid-carbide tooling solutions with a number of small vendors still being a necessity for special applications.
Concluding on this point, Townsend says: “ITC has proven that its solid-carbide end mill and drilling lines can outperform everything we have trialled. But most importantly, the support from Gary Bambrick has been exemplary. Gary has not only instigated the introduction of new products, but also new strategies to enhance productivity.”
For further information www.itc-ltd.co.uk