Golfers who own "Big Bertha" drivers made by Callaway Golf Company should thank a Brigham Young University professor and a machine he invented for their monstrous tee shots.
Back when the club was first introduced in 1991, there were some instances when the golf club's shaft suffered from cracking above the massive head. Callaway Golf immediately replaced any faulty clubs, but company engineers wanted to know what caused the breakage.That is when they called Bill Pitt, a BYU professor of chemical engineering with expertise in stress analysis.
Golfers were returning the drivers because they were "blistering" at the point the shaft enters the head, Pitt says, explaining that blistering occurs "when a thin layer of carbon fibers that make up the shaft bulge out. It's caused when a golf ball strikes too highly on the heel of the driver."
The 39-year-old professor first used an electron microscope to detect defects in the shaft's fibers.
With the help of Nathan Lee, then a graduate student, Pitt built a machine to perform stress analysis, or simulate the quick impact of a golf ball striking the head of a club.
With the press of a button, the bar crashes down on the golf club shaft, and the machine's sensors measure the results of the impact .
Upon Pitt's recommendations, Callaway quickly corrected Big Bertha's problem and produced an even better club.
Lee now operates the simulator for Callaway in Carlsbad, Calif.
"We were able to strain a golf shaft in a way that is similar to the way a golfer strains his shaft when he hits a ball with his club," Lee says of his work with Pitt.
Knowing how to re-create the same failure that was plaguing golfers on the links helped Callaway to further improve its club design.
Callaway engineers now use the machine to increase the strength all the company's club shafts, Lee says.
"The machine allows you to do strength testing on the shaft without building the whole club - that saves time and money."