Go Kart

During my senior year me and another student decided to create a class where we would create a functioning go kart. Our goal was to have a go kart that had an autonomous and driver control mode.

Research

Before constructing the go kart we researched the components that we had available to us at our school.

Kart Research

Gantt Chart

The Go Kart

Drive Train

The go kart is two wheeled drive. We used two 2.5" Cim Motors (am-0255). Each motor powered a CIMple gearbox that had a gear ratio of 4.67:1. The gear box were then connected to the wheel with chain.

Left Side Drive Train

Right Side Drive Train

Frame

To construct the frame we used 80/20 aluminum and plywood. This helped us keep the frame light and strong.

Electronics

We use a 12V lawn mower battery to power the go kart. The battery powered a power distribution panel. The power distribution then powers the two motors, two fans, two motor controllers, and light. The Vex cortex is powered by a smaller 12V battery. The Vex cortex powers three ultrasonic sensors and a speaker.

Vex Controller(top left), Motor Controllers(top middle and right)

120mm Fans

Breaker

Power Distribution Board

Cooling System

The motors we used overheat after an extended period of use. To prevent this we designed a cooling system than uses two 120mm fans to push cool air over the motors.

120mm Fans

programming

We used easy C to program the go kart. The go kart has two modes that are run from the same program. Autonomous and driver control. Driver control lets the driver control where to drive the kart and honk the horn. Autonomous is entered when the driver presses the left bumper on the remote. In this mode the go kart will drive in the middle of a hallway and stop when it detects and object that is four feet or less in front of the kart. How the kart stays in the middle of a hallway is it uses ultrasonic sensors. The front ultrasonic sensor is used to detect the distance objects are in front of it. The left and right ultrasonic sensors are used to calculate the distance it is from a wall. The kart will drive forwards when it sense the left and right distances to the walls are equal. It will turn slightly if those distances are not equal. When the cart emergency stops the light will flash at the driver and the horn will beep.

Right side and front ultrasonic sensors

Left side and front ultrasonic sensors

All ultrasonic sensors and emergency stop light

Wiring for ultrasonic sensors and light

Control

We used a Vex cortex to control the go kart. The Vex cortex is the brain behind the autonomous mode and driver control mode. Vex Controller(top left), Motor Controllers(top middle and right).

Manufacturing

We used a variety of tools available to us to build the kart. We used band saws, drill press, CNC machine, drills, saws, wrenches, screwdrivers, wire cutters, and a variety of other tools. In addition, we used the CNC machines to manufacture an improved motor cap.

Motor Cap Top View

Motor Cap Bottom View

comfort

This was one of the most important parts about the go kart. If the driver was not comfortable they would have a bad experience. To ensure the driver was comfortable we used an old office chair -that can recline and we have a foot rest.