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J&S Suprema grinder fits the purpose at Bowmill
In its new Tewkesbury, Gloucestershire manufacturing plant dedicated to the production of Airbus landing gear kits, Bowmill Engineering Limited has installed a Jones & Shipman Suprema EASY cylindrical grinder as part of its multi million pound machine tool investment programme that also includes 8 new machining centres and high levels of automation throughout.
The factory in Tewkesbury replicates a similar bespoke facility at Bowmill’s headquarters in Poole, Dorset where it operates a dedicated facility for Airbus landing gear kit production. Bowmill has been manufacturing A320 and A330 landing gear kits since 2002 as well as complex components and assemblies for other OEM’s.
Both sites operate as full production manufacturing operations producing Class 1 critical components with a particular emphasis on the A320 and A320neo aircraft which are currently on intense build schedules.
Kits from Tewkesbury – which are delivered on a tight KANBAN regime – are despatched to customers based in nearby Gloucester as well as Canada and Mexico. Phase one of the new investment will see the Tewkesbury plant concentrate on A320 kits but Phase 2 – accommodating components for other Airbus aircraft and aircraft builders – will come on-line later in 2017.
Nick Epps is Managing Director of Bowmill Engineering Limited and when it came to specifying the grinding machine he admits a particular affinity with Jones & Shipman.
“I’m a time served toolmaker by trade and a good deal of my apprenticeship was undertaken using J&S manual machines. Here in Bowmill we operate three J&S’s in Poole and a sister company of hours – Taymar Precision Grinding – also operates a number of J&S machines.
“The Jones & Shipman Suprema EASY is a multi-purpose machine that has established a reputation as a true ‘all-rounder’ being equally adept at processing high volume production grinding work or fulfilling high precision small batch quantities and one off work as encountered in environments such as Bowmill,” he explains.
Bowmill has identified 9 critical Class 1 kit components that require grinding tolerance finishes – retaining pins, uplock pins and spacers. Some are chrome plated – a grinding challenge in itself – but all grinding programmes are stored in the memory of the machine’s EASY graphical software which offers a real advantage with its speed of set-up for dressing and grinding cycles utilising touch screen technology.
Bowmill’s machine has a 650mm grinding capacity between centres although longer 1000mm and 1500mm capacities are available. The model is also the external wheel head version specifically designed to offer unrivalled ease-of-use coupled to the highest levels of productivity.
When the Tewkesbury factory is in full operation the grinder will be used 24 hours a day so the robust and comprehensive design and build specification was a key factor when purchasing. The ongoing need for high geometric accuracy with quick changeovers between different grinding operations will be vital to maximise machine usage.
In addition to a new colour touch screen interface is the latest Fanuc power motor control that offers increased machine storage with the potential for thousands of dressing and grinding programmes. It also offers increased processing speeds to further optimise programming and set up’s along with improved connectivity via a USB port.
Other features of the Suprema include the latest Fanuc digital drives and motors, Heidenhain’s 12.5nm scales to both the vertical and crossfeed axes and increased diameters on both the left and right hand external wheels for the universal wheel head configuration. This produces longer wheel life and improved productivity by reducing the number of dresses required in the grinding cycles.
Comments Nick Epps; “We identified that in the Tewkesbury factory there were specific processes that need grinding so we needed a machine with proven production capability and consistent high tolerance repeatability. It was a tight brief and one the Suprema has met. In addition, the EASY software is well liked by the engineers.
“Throughout the new operation we have concentrated on optimising and reducing machining times as we operate in a very ‘cost down’ environment,” he adds. “Also keeping grinding in-house gives us very much more control and manufacturing flexibility. All components are NDT flaw detected as part of our quality regime so full transparency is all important.
“On cost reduction we have reduced machining times by 21%, defects by 17% and reduced raw material usage by 28% and the Suprema has certainly made a major contribution to these efficiencies and savings.”
Unusually for the aerospace sector, Bowmill is the single source global supplier of A320 kits but contract obligations necessitate we operate from two distinct manufacturing centres – hence the new Tewkesbury plant investment.
Landing gear kits manufactured by Bowmill comprise a number of variants including the Airbus A320 (A321) and new A320 neo single aisle planes, the others being for the A330/A340. All kits are produced in left and right side versions and in standard and heavy duty versions. The A320 kit has 82 items whereas the A330 has 221 with each kit comprising sub assembled and individual items with class 1 (critical part) to class 3 component ratings.