The jig is up: EWIRA adds flexibility to regional aircraft manufacturing
The EWIRA project, funded by the European Commission’s Horizon 2020 programme under Clean Sky 2, has been successfully progressing its jig-less jig assembly concept to the next level.
A jig-less jig concept has been developed that trims the time and cost of assembly tooling in aircraft structures by reducing or eliminating some of the tooling manufacturing activities, as previously reported at the midway point of the project. The EWIRA consortium is comprised of Aciturri (the EWIRA consortium coordinator) as well as Caetano Aeronautics of Portugal and the UK’s Manufacturing Technology Centre.
The time and cost savings are achieved by providing support just where it's needed rather than using a complete frame around the manufactured part. This more skeletal approach to jig design provides flexibility to accommodate design changes, and is ideal for low production rates.
Clean Sky project officer Costin-Ciprian Miglan notes that the jig-less concept is ‘a very innovative assembly line, which has a system of lasers in order to calculate all the positions to put the devices to be manufactured.’
In Jan 2018 there was an initial validation at TRL3/4 of the jig-less concept with the assembly of a scale-sized aileron.
‘The aileron had just a 1.5 m span but this was enough to validate the technology which focused mostly on reducing the cost of the assembly jig due to a considerable reduction in elements compared to conventional jigs,’ says Jorge Martínez San Martín, Programme Manager for Engineering and R&D at Aciturri.
Further validation at the end of 2018 confirmed, says Clean Sky's Miglan, ‘a 25% reduction in tooling costs, proving a very good benefit for the future.’
By the beginning of 2019 the consortium produced a full scale jigless-manufactured set of ailerons. These were delivered in Q3 2019 to Airbus Defence and Space for installation into the Clean Sky Flight Test Demonstrator, which will take EWIRA’s (now patent pending) jig-less technology to TRL6.
‘This was developed for Flight Testbed 2, but it can be adapted for other devices as well,’ says Miglan, ‘so this shows important exploitation potential.’
There were actually three ailerons assembled because one is dedicated to the full scale ground test, and then another two, right hand and left hand sides, are for the actual flying aircraft.
‘A key benefit of jigless technology,’ says Aciturri's Martínez, ‘is that both the right hand and left hand side ailerons were mostly assembled on the same jig. It wasn't necessary to make a mirrored version of the jig to produce a complete set of ailerons.’
Having proven, in 2019, the overall concept of jig-less jig manufacturing, Martinez says that lessons learned from the maturation of this technology are now being used to scale-up the benefits with the development within EWIRA of a flexible jig. This is now being used to produce a representative 11m-wide centre wing section of a regional aircraft.
‘Obviously it's much more massive, and we need many more elements in that jig,’ says Martinez, 'but it's still simpler than the one that would have been used if it had been produced following traditional assembly procedures.’
‘In 2020, we assembled the actual wing of the ground central wingbox demonstrator, which will be integrated early this year with engine mounts,’ reports Martinez, adding that the results have been very good with all elementary parts prepositioned with exceptional coordination including spars, skins and ribs.
‘This concept enables us to achieve the required aerodynamic tolerances with a reduction of many hours of adjustment of each part, and also with better ergonomics and lower tooling costs,’ he says. ‘The jig is simpler and cheaper than the one that would have been manufactured following traditional assembly concepts.’
In the last phase of the EWIRA project the jig will undergo minor modifications to facilitate integration with the structural elements of the demonstrator’s wings in 2022. This will further demonstrate the cost-saving benefits of the flexible jig concept.
The results so far of the jig-less and flexible jigs technology bricks demonstrate progress that will benefit European factories as they strive to reduce their CO2 footprints, in alignment with EU environmental ambitions, by cutting cost and time.
The concept can be exploited across a variety of aerospace structures assemblies including wings, stabilisers, control surfaces and even fuselages. The concept can also be applied to the manufacture of any structure requiring precise alignment with respect to the central axis, such as large R&D installations and equipment.