Drexel TPED's Drift Car
The mechanical design was developed using SolidWorks and features a transport, chassis assembly as well as an upper cabin, drift assembly. As the transport assembly moves along the track, the inertia of the cabin assembly swings the vehicle due to centripetal force. Spring-dampers are used to arrest the motion and return the vehicle to the nominal, straight position after completing a turn.
The transport assembly consists of four passive casters that support the vehicle. Additionally, spring-loaded drive wheels are mounted to the bottom of the chassis to propel the vehicle along the track. Although not modeled in the renderings shown here, a sprung rotary pivot was considered for the drive wheels to eliminate binding that may be possible with linear rails. Four wheels were determined necessary for the propulsion system including two sprung powered wheels and two sprung passive wheels.
Two mechanical designs were considered for the drifting mechanism consisting of bearing stackups and wheel bogie assemblies. One design included a radial bearing for the pivot as well as a wheel bogie with road wheels and side guides. The other design included two radial bearings and a thrust bearing for the pivot as well as a road wheel for the wheel bogie. Although the first design was initially modeled, the later design was chosen due to its resemblance of a simply supported mechanism - this would prevent the mechanism from becoming an indeterminate system.
Ultimately the project was not continued past the conceptual development phase. Initial calculations showed that the angle of rotation experienced by the cabin would be too small. At this scale, the weight and velocity are not large enough to produce meaningful centripetal forces that would overcome the proposed spring-damper mechanisms. However, scaling the system to an amount relative to a full-scale ride would result in appreciable motion. The primary issue at small scales is the availability of small spring-damper components.