Builders guide robot pacman.pdf

2.0 ChassisThe design objective of the chassis is to enable Pac-Man and the Ghost tomaneuver easily in the maze. Since most of the robots weight comes from thebatteries and motors, in order to keep the weight to a minimum, the chassis wasdesigned to be as lightweight and small as possible. Therefore, 16-gauge sheetaluminum was chosen to be the main building material for the chassis. Thechassis is designed to have three modules: motor mounts, PCB mounts, and thebody. This design makes the robot easy to assemble and disassemble. The detaildesign of each module is described in the following sections.2.1 Motor MountsThe robot is designed to accomplish standing 90 degree or 180 degree turns in themaze. In order to do this, the two motors are positioned in the middle of each sideof the robot, so simply rotating the two motors in opposite directions achieves thestanding turn. To mount the motors on to the chassis body, we made a L-shapealuminum plate (a corner) to attach the motors to the chassis (see Figure 1).Figure 1. Aluminum CornerFigure 2. WheelThe wheels we used, shown in Figure 2, are plastic disks made by the machinistaccording to the specified dimension. The dimensions of the wheels were chosenso it gives the motor and the dot-counting sensor just enough clearance off theground. The wheel clamps straight on to the shaft of the motor using a setscrew,so it has a one to one gear ratio. This is why the wheels have to be made justright, otherwise the robot would be moving faster than the desired speed.2