We, Team Clock 'em Sock 'em, plan to design a basic mechanical clock and hopefully get it 3D-printed. The clock will work using a synchronous AC gearmotor (approximate cost: $24) and several gears to alter the magnitude of the rotational velocity so that the correct time is displayed. The teeth on the gears will be triangular, which is possible given the low rpm of the motor.
The principles used to design the clock will be based on the physical attributes of gears. For example, a gear with twice the number of teeth compared to an adjacent gear will have twice the radius and half the rpm (assuming all the teeth are the same size). We hope to use a motor that rotates at 1 rpm, so the additional gears need only be used for the hour hand.