Innovative Golf Putter Cody Jackson, Jeffrey Keenan, Corey Tillson, Victoria Thacher
Mentor: John Novotny Liaison: Tyler Sullivan
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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
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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
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Objectives and Constraints
USGA Conforming
- Appendix II: Design of Clubs Improved performance Aesthetically pleasing Machinable Corrosion, temperature, and wear resistant BombTech color scheme
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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
MOIz and center of mass were crucial Sound and feel hard to estimate in preliminary stages
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Background Research
Biomechanics of swings Alignment cues Psychological impacts of putting
Yips, nerves, and the average terrible golfer
High Contrast Alignment Cues
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Requirements
COM < 8mm above the club base COM > 15mm behind club face MOIz approaching 5900 g cm2
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
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Design Evolution Phase 1 (August – October)
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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
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Design Evolution Phase 2 (October – January)
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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
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Design Evolution Phase 3 (January – May)
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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
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Final Design Overview
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Final Design Overview
Precision CNC milled by Stephens Precision Inc. One-piece 12l14 Carbon Steel Head E-nickel plated Dot peen engraved logos
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z
y
x
Toe Side
Heel Side
50% of the club head weight is on the outer 25% of club geometry
Large MOIZ - 5850 g cm2 C.O.M. located at 0.4 cm above bottom and 1.7 cm behing the face
Increased sweetspot Mishit management
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z
y
x
Toe Side
Heel Side
Hole in which center mounted shaft is epoxied
Cut out added for weight reassignment and alignment assistance
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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
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Hand-painted, bright green alignment cues
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Analysis
Consistency Testing Initial Roll Characteristic Analysis Pilot/Qualitative Testing
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Consistency Tests
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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
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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
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Testing Rig
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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
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Consistency Results
BombTech Grenade (Sweetspot Distance: 360 inches)
Face Location (cm off face) Average Radial
Dispersion (in) Standard Deviation (in) RDispersion/DSweetSpot
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
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Consistency Results
TaylorMade Rossa (Sweetspot Distance: 359 inches)
Face Location (cm off face) Average Radial
Dispersion (in) Standard Deviation (in) RDispersion/DSweetSpot
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
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Consistency Results
Odyssey Rossie (Sweetspot Distance: 348 inches)
Face Location (cm off face) Average Radial
Dispersion (in) Standard Deviation (in) RDispersion/DSweetSpot
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
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Consistency Results
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
Analysis of Variance (One-Way ANOVA) of Normalized Consistency/Accuracy Test Data
BombTech Grenade TaylorMade Rossa Odyssey Rossie
Face Location
(cm off face) RDispersion/DSweetspot
Standard
Deviation RDispersion/DSweetspot
Standard
Deviation RDispersion/DSweetspot
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
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0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
-4 -3 -2 -1 0 1 2 3 4
Rati
o o
f R
ad
ial
Dis
persio
n t
o I
deal D
ista
nce F
ro
m S
tarti
ng
P
oin
t
Distance from Center of Club Face: Heel to Toe (cm)
Radial Dispersion Vs. Club Face Location
BombTech
Odyssey
TaylorMade
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Initial Roll Characteristic Analysis
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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
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Initial Roll Characteristic Results Normalized Results
Lowest time ratio indicates that the Grenade achieves pure roll the quickest, while minimizing time spent skidding
Grenade, 0.19
Odyssey, 1.14
TaylorMade, 0.89
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
Putter
t(skip
) /
t(1/4
turn
)
Comparison of Normalized Time Parameter
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Initial Roll Characteristic Results Normalized Results
Low velocity ratio indicates that the Grenade induced a lower rotational velocity on the ball, thus less skidding and over-rotation of the ball
Grenade, 2.23
Odyssey, 3.00
TaylorMade, 2.91
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
Putter
ω(1
/4)
/ V(1
/4)
Comparison of Normalized Velocity Parameter
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Initial Roll Characteristic Results High-Speed Footage
BombTech Golf Grenade Putter - Initial Roll Characteristics - High Speed Camera
https://www.youtube.com/watch?v=cyFuyrtW3ok
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Pilot/Qualitative Testing
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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
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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
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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
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Conclusions
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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 28th
Looking Forward
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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!
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
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Questions?
#PullThePin
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