A golf club fitter needs to know the properties of the shafts he is fitting you with. I first learned about shaft profiling from Tom Wishon. He assembled a database of linear shaft bend profiles using a strain gauge frequency instrument. It got my interest and I put a great deal of time into frequency profiling shafts on my own and developed a rudimentary database of my own.
During a visit to a shaft company R&D site I was introduced to the concept of EI profiling. That began my exploration of other methods of describing the properties of a golf shaft. I learned the term EI from engineers in the business of designing shafts. The instrument used was in the $10K+ range, not affordable to most. Not even all shaft companies had these instruments.
It took about 2 years to come up with an workable, affordable EI measuring design. After many years of use, I decided it was time to redesign and improve the original. I knew all the sources of error in the original design and fixed them. The machining was beyond the capacity of my mill and I had to outsource the cutting of the parts. The precision of the parts made by a machine shop further improved the instrument and made designs I could only imagine possible.
The new design far exceeded expectations. Most of the original instruments have been upgraded. A number of my instruments are now owned by shaft companies. The latest to acquire one has reported it is the fastest, easiest to use and most accurate instrument in the business. The first production run of the new instruments is nearly sold out and a second production run is commencing.
Recent promotion of hoop strength by a shaft company lead me to explore how hoop strength is measured. One method is compression testing. A tube is placed on a block and a weight is placed on it. The amount it bends under this load is a measure of hoop strength. After a few tests I designed a support and added hoop strength measurement to my instrument and database.
With a driver shaft database of 1200 shaft profiles that include stiffness, torque and hoop profiles, I and my affiliated fitters know the shaft you are being fit with. That knowledge makes us exceptional fitters. Six of the fitters using this system are on the recent Golf Digest Top 100 ClubFitters list. To learn more about the instrument and software look at the bottom of the Products page for links.
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