Beer Pong Robot

The video demonstrates me controlling the full final system using two potentiometers. In this demo, I am using three high-torque servos to move the entire system: one as the pan motor and two as tilt motors. Although each servo has high torque, a single servo was not sufficient to be used as a tilt motor. When only one high-torque servo was used as the tilt motor, the shooter would slightly shift downward, mainly because the top part of the servo is small and lacks a secure attachment point. As a result, during movement, the shooter would sometimes come off entirely, making the use of two tilt servos necessary for stability.

The image depicts the final 3D model of the shooter. The main modification is the enlarged compartment at the back, designed to accommodate a larger solenoid. Neither the small solenoid nor the micro servo provided enough force to eject the ping pong ball when the shooter was tilted upward, making the larger solenoid the only viable option. Additionally, the compartments for the two DC motors were shifted slightly toward the back. This adjustment was necessary because, at times, the solenoid did not push the ball far enough, and positioning the motors closer to the back helped address this issue.

The image showcases an alternative 3D model of the shooter, with the primary difference being the back section. Instead of a small solenoid, this version includes a compartment for a servo. After realizing that the solenoid lacked sufficient force, I tested whether a servo with an attached servo horn could provide enough force to push out the ping pong ball whether the shooter is tilted upwards. However, this approach also proved ineffective. As a result, this model was not used as the final version. Nonetheless, experimenting with different designs and "pushing out" mechanisms was valuable in determining the best fit for the system's needs.

The video captures me testing the launching mechanism of the system. The two horizontal flywheels must rotate outward, with one spinning clockwise and the other counterclockwise. This setup, combined with high-speed motors, enables the ping pong balls to launch in a parabolic trajectory. Most shooting mechanisms utilize either a horizontal or vertical flywheel system.

In the video, I was testing the DC motors and their stability. The flywheels were not a snug fit on the motors, causing them to slip slightly and misalign while spinning. In later iterations, I 3D-printed multiple flywheels to find the best fit with minimal slippage. The motors were also slightly misaligned due to differences in how they were taped and the vibrations from high-speed movement. While the setup was relatively stable, further adjustments were needed to ensure proper alignment of both the motors and flywheels so they remained centered on the ping pong ball.

The video demonstrates me controlling the entire system using two potentiometers - one for the pan motor and the other for the tilt motor. In this setup, both motors are stepper motors, chosen for their durability over micro servos.

The video shows me using a potentiometer to control the pan motor, which is a stepper motor. I chose a stepper motor for this role because the micro servo was too small and lacked durability. However, when mapping PWM values from the potentiometer to the stepper motor steps, I couldn't find a precise formula that ensured perfect accuracy. As a result, there are slight delays between adjusting the potentiometer and the stepper motor's movement.

The image displays the initial 3D model of the shooter, the core component of the system. The back of the shooter includes space for a small solenoid, positioned at the center of the ping pong ball. However, I later realized that a small solenoid lacks the necessary force to propel the ball effectively, especially when the shooter is tilted upward and gravity is working against it.