CAD Design

Our robot mechanically has three levels. The main structural components are two laser-cut aluminum sheets, spaced by steel spacers. We want to run the robot at a high moving speed to maximum points and also incorporate a high-speed flywheel launcher. Both features requires a strong chassis. Aluminum is the ideal material due to its high strength to weight ratio compared to plastic or hardboard. We hand-tapped numerous threaded holes to the plates for securely mounting other components. This also wouldn't be possible with plastic or hardboard.

Additionally, to enable our robot to move along the walls, we added bearings with printed TPU covers at the corners of the chassis. They are the outmost features of the robot.

At the bottom level of the robot, two batteries are secured with two 3D-printed brackets. The brackets are screwed onto the aluminum plate and the batteries are snap-fit to the bracket for easy installation and removal. Battery cables, connectors, and fuse are between the two batteries and not shown in CAD. REFLECTION: I wish we designed brackets to hold the cables and connectors and fuse because we had to retape them every time we reinstalled the batteries, and they were very close to the ground.

The circuit breaker is mounted to a 3D-printed bracket that is bolted to the chassis.

In reality, we also added black cardboard taped to the chassis to sweep away balls that are in the way of the travel.

At the middle level of the robot, our drivetrain system lives. This includes 4 motors, 4 wheels, and 4 motor drivers.

Our orientation system consisting of 3 Time of Flight(ToF) sensors is also mounted here. Each sensor is sandwiched between two 3D-printed parts that are bolted to the chassis.

On the top level of the robot, there are the ignition mechanism, the ball dropper mechanism, the celebration mechanism, the launcher, an Arduino, and other electronics.

The ignition, ball dropper, and celebration mechanisms share many components. This approach decreases unique part count and simplifies designs. Each mechanism features a servo, a rotating component, a d-shaft that's connected to the servo and the rotating components, and a support structure for the d-shaft.

In ignition, the rotating component is simply a bar. In ball dropper, the rotating component is a L-bar with a cup at the end. The cup holds one ball securely, and the L-bar enables the cup to drop a ball high and far from the robot.

In celebration, the rotating component is an eyelid that covers and uncovers a 3D-printed eyeball with a googly eye as the iris.