Aurora Cars
The full Holman Building Collection. Clockwise from center foreground: Borealis I, Aurora 2, Aurora 4 and Aurora 3.
This is a brief compilation of photos highlighting the Aurora series (1 thru 4) of solar cars built by the University of Minnesota Solar Vehicle Project. A more detailed history can be found at the Project's website.
The full Holman Building Collection. Clockwise from center foreground: Borealis I, Aurora 2, Aurora 4 and Aurora 3.
Brake pedal and master cylinder for Aurora 1. Also note the steering column and rack in background.
Massive all steel double a-arm/trailing arm hybrid suspension for Aurora 1. Note complex steering linkage transmitting from upper right corner through a rotating shaft down to a steering tie rod attached to upright.
Massive steel upright for front suspension. Also not steering linkage at base of upright.
Aurora 1 was a "tunnel-style" car, meaning it formed an arch with a large tunnel passing from front to rear down the car. The solar array was unencapsulated silicon cells.
Note dead pedal on left. Brake is left foot activated and uses a single master cylinder instead of dual redundant system not required by regulations. also note steering shaft passing above master cylinder into steering rack.
Aurora 2 was the lightest solar car ever built by the U of M (discounting batteries). This was partially due to the less restrictive regulations, but also due to lightweight simplified design.
A2's front suspensions. Note uncoated aluminum brake disc and two-part upright design.
Front suspension from A2, note wire wheels (lighter than NGM), bike tires, and compact a-arm design to allow for rearward battery compartment.
A2's swing arm rear suspension. Note Unique Mobility motor with chain drive. Also, poor design of a-arm mounts using rod-ends in bending.
Unique rollbar using a double thick fibrelam fiberglass panel braced by a pair of aluminum supports. Note also, integration of rear suspension shock bracket with rollbar supports.
A2 used removable solar cell modules to supplement the array power during stationary charging. These cut out panels also allow access to the underside of the upper array for construction and maintenance.
Very clean underside wiring of Aurora 2 solar array. Large cells and non-removable modules simplifies wiring.
Aurora 3's automatic body opener powered by a gas charged strut and the driver protective roll bar in the foreground.
Note very smooth surface integration of turn signal lenses with aerodynamic body shell.
Note poor fitment of canopy to body shape. Also note this canopy is non removable and is not used for driver egress due to hinged body shell.
Jason and Mitch check out A3's front suspension system. Aurora 1's silver shell is in the foreground.
A3 used a rotating aerodynamic filler to block air from entering around the wheels. The filler was turned using a rod connected to the upright.
Note two part upright, shock angle relatively close to horizontal, shock mounted to upright instead of lower a-arm, and the circular rotating aerodynamic filler.
Note mounting of upper and lower a-arm and shock. Also note lever that turns the aerodynamic filler panel with the wheel.
The last of Minnesota's "wing-style" bubble canopied solar cars. A4 was incredibly thin necessitating an extremely reclined seating position and push-pull steering apparatus.
Linkage for brake master cylinders operates each cylinder in opposite direction using 4 bar linkage.
A4's chassis introduced the "electrical trunk" behind the driver, also notice automatic shell opening arm powered by a gas charged strut.
Front quarter view of chassis. Note orange-board fibrelam composite chassis, push-pull steering, and hinged aero body.
Rear view of A4's chassis. Note 4-wheel layout, right rear drive wheel, and very slim body.
Aurora 4 front suspension. Note lightening cuts in upper a-arm, well developed fairings (though unnecessarily aerodynamic inside the body), use of integrated jig/brackets for mounting points.
Note heavy solid hub, coated aluminum brake disc, dual slave brake cylinders, large upright (due to thin body) and strange outward curvature of upright for machineability.
A4 rear suspension, note small vertical separation of upper and lower a-arms due to thin profile of car. Also, integral jig/suspension mounting brackets ensuring correct mounted geometry.
Right rear suspension, note lower upright bolt is common to shock, lower a-arm, and toe link.
