Exploration of Center of Gravity, Moment of Inertia, and Launch Direction for Putters with Ball Speed Normalizing Face Properties

Jacob Lambeth,Dustin Brekke,Jeff Brunski

doi:10.3390/proceedings2020049002

Abstract

The forgiveness of golf putters is traditionally achieved through weight distribution. Putters are often designed with large footprints, which help to increase the moment of inertia (MOI), but consequently move the center of gravity (CG) farther behind the face. The use of higher MOI putters will result in less ball speed loss on impacts away from the sweet spot (i.e., more forgiveness). It has been shown that certain face properties, such as milling patterns, grooves, or soft inserts, can be leveraged to have a similar effect. This paper explores the relationships between impact location, MOI, CG depth, discretionary mass placement, and launch direction for these putters. A novel design strategy is proposed. Minimizing CG depth for putters with ball speed normalizing face properties, even at the expense of MOI, can result in more consistent launch direction and distance control for the average player.

Highlights

Putting accounts for more shots taken during a round of golf than any other type of shot [1].One of the primary difficulties faced by amateur golfers is swing variability
This paper explores the relationships between moment of inertia (MOI), center of gravity (CG), and launch direction, while assuming ball speed is constant over some region of the putter face
A rigid body impact model was used to determine the relationships between impact location, CG depth, heel-toe MOI, and launch direction

Summary

Introduction

Putting accounts for more shots taken during a round of golf than any other type of shot [1].One of the primary difficulties faced by amateur golfers is swing variability. Amateurs tend to impact the putter face over a relatively large area, increasing the need for performance on poor strikes. For a golfer of handicap 18 and greater, this impact zone approximately resembles an oval with a width of 1.5 in and a height of 0.75 in [2]. These mishits lead to errors in both speed and direction [3,4]. MOI is a measure of an object’s resistance to angular acceleration (rotation) around an axis for a given torque It is a function of an object’s mass distribution relative to the axis of rotation. Energy is transferred more efficiently to the ball, decreasing the penalty for a poor swing

Methods

Discussion

Conclusion