Hi everyone,

My name is Martin Chavez and I plan on graduating in the spring of 2017 with a BSME with a capstone course in mechanical design. I will be working on the half scale propulsion design for the 2015-16 Spartan Superway project. The propulsion drives the bogie along the guideway; without a propulsion system, the bogie would not move. In addition, the propulsion team will have to take the inclination of the guideway and braking into consideration for the motor selection. The propulsion team will be responsible for determining the specification for the theoretical model, selecting an appropriate motor and controller, designing a mount for the motor, and developing code for the steering and braking of the bogie. 

The half scale propulsion team from last year succeeded in calculating the theoretical values for the resistances, forces, and power required to overcome the inclined slope in order to select an appropriate motor. The team selected a direct drive hub motor, the Crystalyte hub motor model 408. The direct-drive hub motor is more durable, faster, quieter than the geared drive motors, and its cash value is much lower too. This motor also met the sizing constraint within the bogie. For the coding aspect, the steering code was integrated to the propulsion code. 

Some failures for the previous half scale propulsion teams are that the team was not created until a month start into the senior design course, which set them back.  Furthermore, the team had trouble during the initial stages of implementing the propulsion code. The team had to troubleshoot the wiring between the steering and propulsion team was done correctly when the power inverter and power supply were mounted on the bogie. To build on the previous design, a spring was used to press the hub motor into the ceiling of the guideway which led to an issue when loading the bogie onto the guideway. The issue was due to the compression of the spring which did not allow the bogie onto the guideway.

Some areas of improvement, as recommended by last year’s half scale propulsion team, include advancing the method of pressing of the hub motor into the ceiling of the guideway and the controls theory aspect.