Group O - Lacrosse Ball Passer

The goal of our design group was to make a lacrosse ball passer that could be used in a team practice or individual setting. Wayne Jaekle, WashU’s head lacrosse coach defined major customer needs as producing a consistent pass speed and angle, an interactive interface allowing an automatic time interval between passes, and being easy to load. These needs lead to our main design goals: 1. A ball capacity of 30, 2. A minimum pass speed of 30 mph, and 3. A 5 second time interval between passes. Mock ups and brainstorming exercises led to our team’s selection of a concept to move forward with, a horizontal, two-wheeled design with a conveyor system used to feed balls between the wheels to launch the ball. Different engineering equations were used to determine the theoretical speed we could shoot a ball based on the diameter of our wheels, which helped guide us in the selection of motors and wheels. Once these parts were specified, they were mounted on a sheet of plywood at a ten degree angle, and the feeding mechanism was built off of this. We set a five gallon bucket above the motors with spiraled HVAC tube inside to hold the balls. The ball would drop from this bucket into a jai-Alai stick, which rolled the ball into a modified PVC pipe and into the wheels, launching the ball. This design met the goals of holding 30 balls and producing a 30 mph pass. Due to cost considerations and lack of time, a conveyor feeding system was not used, nor was a time interval for passes developed. After completing this project, our team learned the importance of sticking to a formulated design process and have become more inspired to attempt new designs