Our Aerodynamics team has been working tirelessly to manufacture one of the most complex Aerodynamics packages that the team has ever designed. Our 2017 Aerodynamics package will feature a four part system, consisting of a front and rear wing, undertray, nose cone and body work. Starting from the raw materials, a great deal of preparation is involved in producing the smooth and glossy finish on all the pieces within the package. In order to validate our designs and achieve maximum Aerodynamic efficiency, it is vital to ensure that we produce parts that replicate our designs as accurately as possible. Furthermore, as skin friction drag is directly proportional to surface roughness, it is essential that the surface finish of the carbon fibre is smooth and continuous. To achieve this accuracy and level of detail, the Aerodynamics team have utilised the high precision engineering capabilities of a number of industry partners.
The process of mould preparation begins with an assortment of polystyrene foam moulds, which are cut by our sponsor C5 Systems, and plastic moulds for our front wing flaps, which were generously 3D printed by 3D Systems. To strengthen the foam moulds, they are coated with a layer of 30 g.s.m. chop-strand fiberglass and resin. This extra layer of fibreglass provides the moulds with the strength to endure the pressure forces from carbon layups. Additionally, it protects the polystyrene foam from general wear and tear, and any substances in the environment that may damage it. As a result, the moulds become durable enough for reusability, allowing us to make multiple carbon parts using the same mould.
However, in order to produce a smooth carbon fibre surface, the moulds too must have surface finish that is as glassy as possible. As the fibreglass chop-strand has a rough surface, further post working is required on all the moulds. Body fillers, glass-bead (Q-Cel) reinforced resins are used to fill any holes and inconsistencies that may exist in the moulds, resulting in hard and even surfaces. The surfaces are then sanded back to ensure they match the intended shape.
To achieve a glossy and glass-like finish, the moulds are then painted with a 2K Primer, courtesy of our sponsors at Valspar. The paint fills in any remaining microscopic holes or low spots, and further refines the surface of the moulds. For a few selected moulds, gelcoats were also implemented into the procedure to further enhance the surface finish. The moulds are then once again sanded, at increasingly higher sandpaper grits, until the moulds are as smooth as glass and ready for a carbon fibre lay-up.
On any individual mould, this entire preparatory process can take up to a few weeks to complete to a high level of quality. Finally, the carbon fibre lay ups begin, followed by curing and trimming of the parts and final assembly. The team eagerly awaits our flying date, as it signals the completion of M17-E and M17-C, and their respective Aerodynamics packages.
– Paras Bhutiani (Aerodynamics)