Publication Date

Fall 2018

Document Type

Final Report

Embargo Date


Problem Statement

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.

Author's School

McKelvey School of Engineering

Author's Department

Mechanical Engineering and Materials Science

Class Name

Mechanical Engineering Design Project (MEMS 411)