Innovative Golf Putter Cody Jackson, Jeffrey Keenan, Corey Tillson, Victoria Thacher Mentor: John Novotny Liaison: Tyler Sullivan 1
Problem Statement Improves consistency of short game performance Complies with USGA regulations Visual alignment cues Generates pleasant sound Generates pleasant feel Aesthetically pleasing Promotes smooth ball roll -Topspin -Decreased ball loft 2
Project Importance Putting accounts for over half the shots taken in a game of golf BombTech golf released their first club in 2012 Putter will be crucial in branding BombTech Ensure user enjoyment 3
Objectives and Constraints USGA Conforming - Appendix II: Design of Clubs Improved performance Aesthetically pleasing Machinable Corrosion, temperature, and wear resistant BombTech color scheme 4
Background Research Examined all aspects of putter geometry Scholarly articles and research Looked at other top market putters USGA regulations Difficult to find competitors information MOI z and center of mass were crucial Sound and feel hard to estimate in preliminary stages 5
Background Research Biomechanics of swings Alignment cues Psychological impacts of putting Yips, nerves, and the average terrible golfer High Contrast Alignment Cues 6
Requirements COM < 8mm above the club base COM > 15mm behind club face MOI z approaching 5900 g cm 2 Majority weight positioned on outer 25% of club High contrast, distinctive alignment cues Heavy head > 400g Acceptable sound Acceptable feel Face angle 2-3 degrees Comparable results with market putters 7
Design Evolution Phase 1 (August October) 8
Design Evolution Phase 1 (August October) Phase 1 focused on Aluminum as primary material Aluminum considered for potential machining at UVM and lowered costs Considered using inserts in body and face Aluminum discarded in favor of carbon steel, which is a higher quality putter material 9
Design Evolution Phase 2 (October January) 10
Design Evolution Phase 2 (October January) Phase 2 focused on carbon steel as primary material Inserts were discarded as a possibility in favor of a one-piece design Preferred design shown below Preferred design discarded due to high machining and production costs 11
Design Evolution Phase 3 (January May) 12
Design Evolution Phase 3 (January May) Phase 3 focused on carbon steel as the primary material Designs were created with consideration for minimizing machining cost Distribution of weight to outer portions dominated design themes Final design chosen by client as design best suited for market and distribution 13
Final Design Overview 14
Final Design Overview Precision CNC milled by Stephens Precision Inc. One-piece 12l14 Carbon Steel Head E-nickel plated Dot peen engraved logos 15
Toe Side z 50% of the club head weight is on the outer 25% of club geometry x y Heel Side Large MOI Z - 5850 g cm 2 C.O.M. located at 0.4 cm above bottom and 1.7 cm behing the face Increased sweetspot Mishit management 16
Toe Side z Hole in which center mounted shaft is epoxied x y Heel Side Cut out added for weight reassignment and alignment assistance 17
Face angle 2.5 Promotes topspin Reduces backspin Reduces skipping Rounded bottom Helps with club lies when player rests it on the green Prevents digging 18
Hand-painted, bright green alignment cues 19
Analysis Consistency Testing Initial Roll Characteristic Analysis Pilot/Qualitative Testing 20
Consistency Tests 21
Consistency Tests Determined dispersion of putts hit off the center of the club, also known as the sweetspot Velocity on off center hits decreases due to energy loss as ball deviates from the center point on face Lose of energy leads to putts that stray away from desired target and travel shorter distances 22
Consistency Tests Consistent pendulum-style putting rig developed to produce constant, low error and bias putts at a fast rate Radial dispersion distances of shots varying from the clubface center compared to determined optimal distance on shots off the center of the face Three putters used for comparison BombTech Grenade, Odyssey Rossie, TaylorMade Rossa 23
Testing Rig 24
Test Parameters Three Putters Control set as average distance and location on shots from sweetspot One cm variations off of the center: up to four cm toward heel and toe 20 trials per face location Results averaged and variance/standard deviation analyzed 25
Consistency Results Face Location (cm off face) BombTech Grenade (Sweetspot Distance: 360 inches) Average Radial Dispersion (in) Standard Deviation (in) R Dispersion /D SweetSpot Heel -- 4 37.250 8.447 0.104 Heel -- 3 26.850 10.577 0.075 Heel -- 2 16.813 10.130 0.047 Heel -- 1 16.200 3.918 0.045 Center -- 0 N/A N/A N/A Toe -- 1 12.775 6.219 0.036 Toe -- 2 12.050 6.547 0.034 Toe -- 3 35.675 8.580 0.099 Toe -- 4 59.500 11.371 0.166 26
Consistency Results Face Location (cm off face) TaylorMade Rossa (Sweetspot Distance: 359 inches) Average Radial Dispersion (in) Standard Deviation (in) R Dispersion /D SweetSpot Heel -- 4 77.575 10.700 0.216 Heel -- 3 48.163 7.940 0.134 Heel -- 2 27.500 7.210 0.077 Heel -- 1 22.175 8.430 0.062 Center -- 0 N/A N/A N/A Toe -- 1 18.145 10.630 0.051 Toe -- 2 28.100 7.870 0.078 Toe -- 3 54.815 9.670 0.153 Toe -- 4 100.588 12.130 0.280 27
Consistency Results Face Location (cm off face) Odyssey Rossie (Sweetspot Distance: 348 inches) Average Radial Dispersion (in) Standard Deviation (in) R Dispersion /D SweetSpot Heel -- 4 132.458 10.670 0.380 Heel -- 3 86.163 13.090 0.240 Heel -- 2 57.920 14.470 0.170 Heel -- 1 31.855 16.150 0.090 Center -- 0 N/A N/A N/A Toe -- 1 17.030 8.490 0.050 Toe -- 2 22.798 15.150 0.070 Toe -- 3 64.053 18.980 0.180 Toe -- 4 110.588 17.110 0.320 28
Face Location (cm off face) Consistency Results Analysis of Variance (One-Way ANOVA) of Normalized Consistency/Accuracy Test Data BombTech Grenade TaylorMade Rossa Odyssey Rossie R Dispersion /D Sweetspot Standard Deviation R Dispersion/D Sweetspot Standard Deviation R Dispersion/D Sweetspot Standard Deviation Level of Significance (α=0.05) Heel -- 4 0.104 0.022 0.216 0.029 0.380 0.032 1.306*10-36 Heel -- 3 0.075 0.030 0.134 0.026 0.247 0.051 1.949*10-20 Heel -- 2 0.047 0.027 0.077 0.020 0.166 0.040 8.087*10-18 Heel -- 1 0.045 0.013 0.062 0.024 0.091 0.044 3.027*10-5 Center -- 0 N/A N/A N/A N/A N/A N/A N/A Toe -- 1 0.036 0.017 0.051 0.027 0.049 0.026 0.103 Toe -- 2 0.034 0.020 0.078 0.024 0.065 0.042 5.379*10-5 Toe -- 3 0.099 0.027 0.153 0.026 0.184 0.056 2.949*10-8 Toe -- 4 0.166 0.036 0.280 0.032 0.317 0.047 1.276*10-17 One-way ANOVA used for analysis Predetermined level of significance set at 5% Null Hypothesis: all mean dispersion ratios are statistically equal Alternate Hypothesis: The mean dispersion ratios statistically differ Significant reduction in dispersion by Grenade compared to other tested putters (Except at 1 cm toward toe) Comparable precision compared to TaylorMade and increased precision compared to Odyssey 29
Ratio of Radial Dispersion to Ideal Distance From Starting Point Radial Dispersion Vs. Club Face Location 0.4 0.35 0.3 0.25 0.2 BombTech Odyssey 0.15 TaylorMade 0.1 0.05 0-4 -3-2 -1 0 1 2 3 4 Distance from Center of Club Face: Heel to Toe (cm) 30
Initial Roll Characteristic Analysis 31
Test Parameters Automated testing rig used for consistency/ accuracy tests used to ensure consistent trials 500 frames/second high-speed camera Three putters Five trials per putter First ¼ turn determined to be representation of pure roll Skipping, angular rotation, angular velocity, and translational velocity examined 32
t(skip) / t(1/4 turn) Initial Roll Characteristic Results Normalized Results Comparison of Normalized Time Parameter 1.40 Odyssey, 1.14 1.20 1.00 TaylorMade, 0.89 0.80 0.60 0.40 0.20 Grenade, 0.19 0.00 Putter Lowest time ratio indicates that the Grenade achieves pure roll the quickest, while minimizing time spent skidding 33
ω(1/4) / V(1/4) Initial Roll Characteristic Results Normalized Results Comparison of Normalized Velocity Parameter 3.50 3.00 Odyssey, 3.00 TaylorMade, 2.91 2.50 Grenade, 2.23 2.00 1.50 1.00 0.50 0.00 Putter Low velocity ratio indicates that the Grenade induced a lower rotational velocity on the ball, thus less skidding and over-rotation of the ball 34
Initial Roll Characteristic Results High-Speed Footage BombTech Golf Grenade Putter - Initial Roll Characteristics - High Speed Camera https://www.youtube.com/watch?v=cyfuyrtw3ok 35
Pilot/Qualitative Testing 36
Test Parameters Survey created to gather independent tester s opinion on sound, feel, and appearance Portable putting mat set up in public space (between Davis Center and Bailey-Howe Library) to attract potential testers Three putters provided for comparison Project explained to tester s, who were encouraged to give honest feedback Surveys taken by friends of team members and non-golfers discarded for accurate analysis 37
Pilot/Qualitative Testing Results Results of Head to Head User Testing (n=10) (Rating out of 10) BombTech Grenade TaylorMade Rossa Odyssey Rossie Sound 8.28±0.29 7.00±1.67 7.50±1.38 Feel 8.50±0.53 7.00±1.41 6.86±1.57 Appearance 8.29±0.83 7.43±1.81 6.43±1.90 Not enough data points to perform full statistical analysis Low sample pool (10 golfers) does show initial opinion trends Sampling at a golf course would ve been preferred, but local courses had yet to open at time of testing 38
Issues With Testing Unable to test with truly comparable CNC, high end putters due to monetary and availability constraints Would ve preferred to test different parameters of putting different impact points, shorter vs. longer putts, variable green speeds Testing occurred on carpet and synthetic putting mats due to poor conditions of local putting greens Difficult to accurately calculate roll ratio due to estimation of geometric parameters 39
Conclusions Putter exceeded expectations in the consistency test ~50% reduction in radial dispersion Statistically conclusive data Roll testing clearly showed quicker production of pure roll ~70% reduction in skipping Received nearly unanimous positive qualitative first impression feedback Putter entered the market April 28 th 40
Looking Forward Current design could be modified to produce a blade style putter if BombTech desires The Grenade will be presented and used during Demo Days at local golf courses Upcoming independent reviews Possibly see it in the hands of a pro on the PGA Tour! 41
Acknowledgments and Thank You s BombTech Golf and Tyler Sully Sullivan John Novotny and Jeff Frolik Stephens Precision and Julian Stephens UVM FabLab and Hunter O Folan UVM-CEMS Student Services Karen Bernard Catamount Country Club Gonzo s HD Sports John Dow, GM of Golf & Ski Warehouse All of our friends and family and their support 42
Questions? #PullThePin 43