27 Apr 2012
Off to a flying start
Tool pre-setters ensure the accurate transfer of tool data and minimise the potential for human error
BAE Systems’ Samlesbury site has a long tradition of design, engineering and manufacturing excellence; it is also home to some of the most advanced aerospace manufacturing and assembly technologies in the world.
Samlesbury is currently contributing to a number of internationally important aircraft programmes; it is also providing manufacturing and support capabilities — as a Tier One ‘team mate’ of Lockheed Martin — for the largest contract of its kind in the world. It is manufacturing and assembling the empennage (vertical and horizontal tail fins) and the aft fuselage of the F-35 Joint Strike Fighter. Central to BAE Systems’ F-35 programme is Samlesbury’s advanced titanium-machining facility, which is housed in a new purpose-built 9,000m2 factory that was designed specifically for the precision finish machining of titanium parts to extremely fine tolerances.
This new world-class manufacturing facility houses two ‘state of the art’ Flexible Manufacturing Systems (FMS) that are each controlled by Fastems software and served by a Fastems pallet system. Because the most-complex F-35 parts require the use of more than 160 tools, the eight Starrag Heckert STC1250 horizontal machining centres in each FMS are provided with very accurately pre-set tools — via robot — from two fully integrated, 2,000-tool-capacity tool stores (pictured left).
At the heart of each Fastems FMS is control software that can: schedule production based on production orders; manage and transfer NC programs; and run unmanned production. In conjunction with TDM tool management software, the Fastems system creates task-lists for the facility’s tool pre-setting department. This information is based not only on predetermined tooling needs, but also on ‘remaining tool-life’ calculations. Tools requiring attention are loaded onto trolleys by the FMS robots and then taken to the pre-setting department.
Need for pre-setting
It is estimated that when both FMSs begin operating at full capacity, more than 800 tools a day will need to be pre-set before being loaded into the machining systems. Given the sheer volume of tools to be assembled and the levels of pre-setting precision required, the correct choice of tool pre-setting devices was fundamental to the efficient operation of both systems. Having investigated pre-setters from several leading manufacturers, the F-35 team purchased four customised units from Northampton-based Kelch UK (www.kelch.co.uk). Simon Scott, BAE Systems’ NC processes team leader, says: “The Kelch tool pre-setters have become an essential element in our production system; they play a pivotal role in linking all relevant data management systems and help in controlling the production of F-35 titanium parts. Moreover, having been involved in the initial design of our integration and data-flow architecture, Kelch personnel provided the communication links with our TDM tool management system and Fastems software; they also ensured trouble-free interfacing with other systems.
“A constant stream of up-dated tool requirements is now sent from our TDM tool management system to the Kelch pre-setter control, providing all of the information needed for the efficient assembly and precise pre-setting of tools. This simple process automatically provides the secure transfer of measured tool values and helps to eliminate the potential for human error, by minimising operator involvement.”
Reading tool IDs
Balluff chip read/write systems are installed on each pre-setter, allowing tool IDs to be read and the relevant measuring programs (hosted on the TDM system) to be requested. “This process ensures that all tools are measured in exactly the same way every time, and it allows us to achieve absolute levels of process repeatability,” says Mr Scott. “All of our tools are now set and measured on our four Kelch pre-setters, and the actual measured values are transmitted to the relevant machine tool control via TDM and Fastems, with tool ID codes used as the relevant file names.”
Peter Horgan, Kelch UK’s managing director says: “Although we were confident that our products were ideal for BAE Systems’ F-35 titanium-machining facility, given the competition for this prestigious order, we were delighted to be selected. Although we are able to provide a wide range of standard products that can accommodate the vast majority of customer requirements, the modular nature of Kelch products makes the implementation of ‘special’ adaptations very easy.
“The modifications that we can undertake are demonstrated by the Kalimat pre-setters in the F35 titanium-machining facility: each machine is equipped with an additional Y-axis automatic setting feature that allows adjustment of the cutting tool in the holder to an exact length. This allows these pre-setters to set a nominal tool length automatically, then measure it very accurately.”