6″ Wheels vs 8″ Wheels

Written by Anila Chundi

The mechanical team decided on using pneumatic wheels for the 2021 season, as they are shock absorbent and offered more speed and maneuverability compared to the 6 in Hi Grip wheels that the team used in the 2020 season. The two types of pneumatic wheels that could potentially work for our robot are the 6 in pneumatic wheels and the 8 in pneumatic wheels. 

The wheels of a vehicle convert the rotational motion of the motor into the linear motion that propels the vehicle forward. In other words, it provides a torque, and this torque is dependent on two variables: linear acceleration and moment of inertia. An object’s moment of inertia is its ability to resist rotation, and it is determined by its radius and mass. An object’s linear acceleration is the rate at which its speed changes. Since the torque is always constant, the object’s acceleration and moment of inertia are inversely proportional.

The 6 in wheels would yield a greater acceleration, as a smaller radius results in a smaller moment of inertia and greater acceleration. The 6 in wheels can also be integrated into our robot design more easily than the 8 in wheels, as they are the same size as the wheels we originally used. For these reasons, our team decided to use the 6 in pneumatic wheels.