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EJ12
 
See also:
The car for 2002
The timescales
The design process
The regulation changes
Making it happen
The monocoque
Vehicle dynamics
The transmission
Front suspension
Rear suspension
EJ12 - the uprights

The EJ12 has four of them and they hold the wheesl to the car. You might catch a two-second glimpse of them when the wheels come off during a pit stop and they are not exactly a "glamour" component. But the uprights are minor masterpieces of design, engineering and build.

"Technically, the uprights are the mechanical fixing at the end of the wishbones which attach the axle, the bearing arrangement, the brake caliper, and the wheel onto each corner of the car," explains Marc Logan, the Senior Design Engineer tasked with designing them for EJ12. "Their design is an evolution of those on EJ11 and, as usual, we have looked at reducing their weight and increasing the stiffness. An upright needs to be stiff enough to support the bearing for the axle and they also have to deal with a lot of heat soak, as the brake discs can reach temperatures of 700 to 800 ºC. On top of that, they have to cope with the cornering loads applied to them and the force of hitting the kerbs now and again. They have a rough life, but play a crucial and unseen role."

Marc Logan

All these different roles make an upright an unusual looking piece of kit, with all sorts of pockets, webs and inner structures as it is hollowed out to save weight. Manufacture is a complex process, involving three-dimensional machining on CNC machines, before the parts are jigged and welded together, before finally being machined.
 
Packaging is tricky as the uprights are also home to items such as the sensors to detect wheel speed as well as providing a mounting point for the brake cooling ducts. "When designing the upright, you have to keep an eye on the rule book to ensure the brake ducts are going to be legal in terms of positioning and that the track width of the car is within the limits," says Logan. "With the front ones, you have to ensure there are no steering problems and make sure the rim is not going to hit the wishbone, so I have to work closely with the people working on the front suspension.

"The initial design process takes a couple of weeks and we go through different configurations of suspension movement on CAD. From there you need around another two weeks to look at other 3D components that make up the upright. It's important to keep up with any changes to the suspension or its geometry change as it might affect my work and we also have to liaise with the  gearbox design team to find out about the length and positioning of the drive shafts. It's a waiting game in some respects, but you can get on with some of the work, as at least you know where the wheels are going!"