Turned out nice - turning technology case studies

5 min read

Highly automated large capacity mill-turning at AESSEAL; differentiated complex one-hit turning investment for a small start-up; and further investment in XYZ technology confirms its suitability at a prototype/small batch specialist

In order to provide game-changing turnarounds on the special mechanical seals AESSEAL manufactures, a new revolutionary concept has been introduced that effectively makes two DMG/Mori Seiki NT4300DCG 1500SZ mill-turn centres (0844 800 7650) its 'stock'. AESSEAL has a diverse product range that spans approximately 300 million product variations, so delivering the right part from stock is not always possible – particularly in the oil and gas sector, where many of the glands are installation-specific. The company manufactures mechanical seals for a wide range of industries, including oil and gas, power generation, chemical, mining, food and beverage, and metal processing. The company's objective is to give its customers such exceptional service that they need never consider alternative sources of supply. It achieves this by despatching 62% of all its products within 24 hours and 72% within 48 hours – worldwide. Image: AESSEAL has invested in complex one-hit mill-turn technology Richard Cook, production and personnel director, explains: "In the oil and gas sector, the majority of installations have fixed pipework. Changing the pipe runs is impractical, so each of our seals has to have a bespoke gland to suit, hence the radical approach to our customers in this market area. The consequence of working in this industry is that customers cannot stock spares for every eventuality and need delivery extremely quickly, as downtime is exceptionally expensive." To solve this problem, rather than attempting to stock combinations of seals in all of its 72 locations, AESSEAL has strategic stocks in key areas of the world from which it builds each assembly to the customers' specific requirements on a just-in-time basis. Where this is not possible - non-standard products for oil and gas customers – it has introduced a flexible and rapid manufacturing cell for core seal components (primarily glands and sleeves) that produces one-off parts, right-first-time and within its timescales. Mr Cook: "Two DMG/Mori Seiki NT4300DCG 1500SZ mill-turn centres are at the heart of our Hydrocarbon Processing cell. Our philosophy has been to leverage technology, rather than increasing stock, so that we achieve highly competitive lead times at the touch of a button. The alternative was to use our existing sequential machining process, with several operations and hence set-ups, carried out on a number of different machine tools." AVAILABLE IN MINUTES Single set-up production of fully deburred, and more accurate parts that feature error-free port identifications and component serial numbers is the result. Production lead times are measured in minutes, not hours or days, with 24 hour, 365 day/year operation available. The main technological elements in this feat are: two 9-axis machines with twin driven-tool turrets and opposed spindles that allow all surfaces to be machined in one set-up and with minimal manual intervention; automatic creation of CAM programs from a 3D CAD model and electronic verification of the post-processed code; an industrial PC on each machine provides access to the latest works orders, designs and CNC programs, as well as the ability to manipulate the 3D model at machine side in a paperless and highly revision-controlled environment; pre-prepared stock material billets, where appropriate, allow an immediate start to machining; quick-change workholding, including 6-jaw chuck technology for thin cross-section workpieces; 120 tool carousel in a standardised layout, with up to 300 tool combinations available at any time. "We have embraced one-hit machining for years on lower-complexity, high volume parts, hence we are very experienced in multi-axis machining. We expanded this to our complex, non-standard manufacturing areas in the early 1990s, but the real step-change has been the further development of this philosophy into multi-tasking technology. We only have one chance to make the part, so the support systems are fully-integrated to eliminate human error at every stage. Very few other companies are at this level of integration, which allows operators to simply load the billet, press cycle start and walk away," Mr Cook adds. "This was an exceptionally complex proposition, yet within just four weeks of machine receipt we were productive. The DMG/Mori Seiki machines have met or exceeded our original terms of reference in every way, resulting in a technological leap that sets new standards," the production and personnel director underlines. As part of its next phase of planned growth, the company is evaluating the replacement of most of its conventional CNC machinery with three more multi-tasking NTs. "This would give us the same machining capacity, whilst freeing up a considerable amount of floor space and existing machinery for inter-group deployment, rendering building expansion unnecessary. We already have the foundations in place for a further eight NTs as part of the original future-proofing philosophy," he concludes. Moving to a smaller operation, but with a similar differentiated focus, and Nick Street set up his own precision engineering company to offer something different and provide a service nobody could match. The technological focal point for his company, Trust Precision, was a Citizen top-of-the-range M32-VIII CNC sliding-head turn mill centre (01923 691500). FIRST EVER UK INSTALLATION The first ever UK installation of the M32-VIII, since its installation in February, it has seen the company go from strength to strength, and not just because of its 35 mm bar capacity, but because it offers "all, and more, of the tools I will ever require" for single set-up, one-hit turn-milling. Image: The first ever UK installation of the M32-VIII, at Trust Precision So successful has Mr Street's early venture into small part turning become that he has recently ordered and installed a Citizen A20-VII CNC sliding-head turn-mill centre to accommodate more 'basic' machining cycles. "The Citizen offers so much more in terms of versatility for a wide range of 'one-hit' applications than any other machine we considered," says Mr Street. "Because of this fantastic tooling capacity, there's no need for me to 'make do' and the M32 can definitely do things no other machine can." It is these higher levels of flexibility available with the tooling, along with the latest control software developments on the M32-VIII, that, he says, has given Trust such an edge over competitors at a critical time. In addition, the control system supports savings of up to 30% in normal non-cutting times, as well as offering energy savings via regenerative technology. Adding these together, Mr Street says: "I have a head start in being competitive on price." Prototype and batch work for a diverse range of industry sectors is the focus for Bedford-based Wickham Engineering. Set up in 1998 by husband and wife team Craig and Heather Wickham, since then the business has expanded to an adjacent unit to double its floor space to 2,500 ft2, while it has become a second home to sons Gavin, 29, and Daniel, 27. "Our expertise extends to light assembly work, and we can also source welding, fabrication and custom finishes, such as plating, anodising or spray painting," explains Craig Wickham. "This enables us to offer a complete service to our customers." The latest investment by the nine-strong company has been a 20 hp/5,000 rpm XYZ Compact Turn 52 turning centre (01823 674200), a 220 mm turning diameter and 52 mm bar capacity machine, which features the easy-to-program Siemens ShopTurn CNC system. The Compact Turn 52 is the fourth full-CNC machine to be supplied by XYZ Machine Tools. "Our choice of machine reflects the fact that we have not experienced any problems with any of our four XYZ CNC machines," underlines Mrs Wickham. Box item Products on the web [] Hydrafeed Multiservo 102 barfeed calculates parts per bar in process - click here [] Space-saving Emco's VT 400 extends large workpiece capability – click here [] Schaublin 136 7AX-Y mill-turn cuts tool setting times – click here [] Haas Automation's multiple operation ST-10Y Y-axis CNC lathe offers less handling greater accuracy benefits – click here [] Okuma 11-axis lathe machines chuck, bar and shaft parts – click here First published in Mavhinery, September 2012