Technology that increases production rates and part quality, while reducing setup times and costs, is seeing a surge in demand within the aerospace sector as the commercial aircraft backlog continues to grow.
An example of
this technology is being developed in the UK by MSP, a company that specializes in precision software and part manufacturing solutions. Their systems work alongside manufacturers worldwide to refine their traditional, longstanding processes, directly leading to reductions in setup and production time, sometimes from days to a matter of minutes, and cost savings routinely running into millions of pounds sterling. Furthermore, as their products can be installed on a manufacturer's current system and operated by an existing workforce, these savings can increase manufacturing capacity by three or four times - crucial for manufacturers committed to improving the efficiency of their processes.
MSP's core patented NC-Checker and NC-PerfectPart products are the key to achieving these gains in efficiency within manufacturing processes, and with the addition of a third product to the suite in the coming months, AutoClock, the production process is set to be completely automated and error-free for the first time. MSP's systems are widely used by companies across the global aerospace sector to aid the manufacture of a wide range of parts including landing gear, skins, engines and interior composite components.
NC-Checker is machine tool benchmarking software that analyzes the movement of the probe tip to ensure it is correctly calibrated and confirmed in five-axis. Otherwise, errors at this stage could affect how accurately parts are machined. The software then performs a series of checks, including rotary and linear axis tests, to produce accurate, easy to understand reports. These ‘benchmark reports’ show whether a machine is within tolerance (or not) and can be used by maintenance teams to plan preventative maintenance and decide when to take the machine down to use Ballbar, Laser Calibration or update the machines pivot points. NC-Checker is also capable of showing if a machine has improved after a maintenance intervention by benchmarking the machine before and after any work.
NC-PerfectPart eliminates errors associated with part production on a machine tool. Following NC-Checker's benchmarking, the software first measures the part to check its condition of supply. If there is too much distortion, or not enough material to create a ‘good part’, the part process can be stopped from the outset. These measurements are then used by the software to calculate what the part alignment should be and the controller is automatically updated to compensate for any discrepancy between the part location and the machining program. All errors due to misalignment are eliminated and the software has a proven record of cutting scrap rates to zero and increasing production by 500%.
Real World Applications
Both products have been involved in projects of all sizes and scales for aerospace companies worldwide, but their work in two BAE Systems fighter jet projects, the Eurofighter Typhoon and F-35 Lightning II, has been particularly significant in the success of NC-Checker and NC-PerfectPart and MSP's growing global presence.
The Eurofighter Typhoon project, which was MSP's first-ever commission following its formation in 2002, faced difficulty with its process for aligning the canard wing on the machine due to the manual setup procedure. The part would have to be located manually within the fixture and then, once machined, be turned over and relocated again to machine the other side. This process had to be repeated twice, using a different fixture each time. Due to the manual measurement and multiple stages involved, it took 7 days to produce one part, 20-30 hours of which was machining time. The rest was setup time. Furthermore, turning the part over caused a cusp or ‘ridge’ to form on the leading edge of the part. Subsequently, one in ten parts were sub-optimal, with the other nine requiring an element of rework, in some cases as much as 22 hours.
After seeing the capabilities of NC-PerfectPart and against a target of 770 parts to make in three years, BAE Systems worked with MSP to design a new process for fixturing the canard wing. Due to the versatility of NC-PerfectPart, the original fixtures could be replaced with a single vacuum fixture, removing the need for turning the part and using multiple fixtures. The process was reduced to four hours 38 minutes, made up of four hours machining time and 38 minutes setup time. No sub-optimal parts were produced and no rework was necessary. In two years, 1,100 perfect parts were made, and due to the time saved, they gained 50% extra machine time which could be used to make other parts – without any investment in extra machine tools required. Over £20million was saved by BAE Systems in five years.
Following the success of the Eurofighter project, BAE Systems approached MSP again to help streamline production of all F-35 skins including the Nozzle Bay Doors (NBD) for the F-35 STOVL (Short Take Off Vertical Landing) variant. A critical step for this was developing the fixture to allow the doors to be machined to tight tolerances despite their complex and varying shape.
Traditionally, complex components similar to the NBD are held in place on fixtures such as vacuum, hydraulic or mechanical fixtures, but in this instance, any of these would have distorted the configuration of this component. Instead, using NC-PerfectPart's ability to automate part setup, the BAE Systems engineering team developed an innovative setup technique, known as sticky fix-turing, a simplified way to hold a component in its free state while it is machined. Part setup was reduced from days to minutes and, again, led to savings above £20million over the lifetime of the project for BAE Systems.
The introduction of MSP's third product, AutoClock, completed the automation process, eliminating inaccuracies at the very start of the machining process by automating probe calibration – something which had not previously been possible. The release of AutoClock came in response to the widespread problem of inaccurate manual clocking and its potential to lead to inaccurate probe calibration, something that can affect machine accuracy and ultimately lead to poor part quality.