Thanks Dave for the explaination. I am familar with John's work but
not Charlie's. Where is Charlie's work posted, and what are the 3
different bearing based spine finders? If I were to speculate, I
would say:
1 - Colin's SpineMaster II or equivalent bearings in plastic tube
2 - Ed Johnson's FeelFinder of SpineTalk / SpineTalkers Forum fame
3 - Dan's Neu-finder 2
DaveT, are these the 3 types of spine finders that you are refering
too, pertaining to the work completed by Charlie?
Would additional machines be:
4 - FlexMaster
5 - Apache machine (not sure what they call it)
Thanks Harry S
www.Golf54.com
--- In [EMAIL PROTECTED], Dave Tutelman <[EMAIL PROTECTED]> wrote:
> At 01:29 AM 10/11/03 +0000, golf54com wrote:
> >Hi DaveT
> >Allow me to provide some background info. to the question:
>
> Harry,
> Thanks for the explanation. I was hesitant to answer the question
as first
> posed because it sounded like a trick question, like there was some
sort of
> "catch". Now that I fully understand the question, I know how to
deal with it.
>
> >Earlier this year, I bought some of the new Apollo steel shafts.
> >I found and marked N. Majority, not all were type 1 per bearing
> >spinefinder. I understand in theory that all shafts are type 2 and
> >not type 1 vs. type 2. I evaluated a dozen and they seemed pretty
> >bad. Most rolled ok on a flat table, so not severely bent. Almost
> >every shaft I tested had a severe wobbler on the N-S plane, to the
> >point my GS freq. analyzer wanted to error out. I've never had the
> >freq. analyzer error out from testing a steel shaft before ... why?
> >Turned it 90 degrees and up to 6 cpm difference between N-S and 90
> >deg. rotation. These steel shafts resembled the graphite shaft
demo
> >that is a severe supershaft. Now I have another 'show and tell'
> >shaft, to share with potential customers. Why wobble on N-S plane?
>
> Why wobble on the N-S plane? Because we disagree on the definitions
of N and S.
>
> * Your definition of N and S is whatever your spine-finder tells
you.
>
> * My definition is the direction of minimum ("N") and maximum
("S")
> stiffness.
>
> Those two need not be the same. And if you EVER find an "N-S plane"
in your
> spine finder (that is, N and S separated by 180*), the two
definitions are
> very different for that shaft.
>
> John Kaufman and Charlie Badami have both done experiments, with
different
> instruments, that show what the engineers on ShopTalk have been
saying for
> years: all shafts are Type 2 if you measure the actual stiffness.
>
> * John has measured a bunch of shafts using both a frequency
meter (hey,
> he makes them for a living) and an "inverted flex board". Both
showed that:
> - Maximum stiffness occurs at 180* intervals, and
corresponds to
> the plane of maximum frequency.
> - Minimum stiffness occurs at 180* intervals (90* away
from the
> maximum), and corresponds to the plane of minimum frequency.
>
> * Charlie has taken a fair number of shafts that show up as Type
1 in a
> spine finder (he has three different bearing-based spine finders)
and found
> the TRUE spine and NBP using a FlexMaster and a procedure we
designed
> together. The true spine and NBP were not nearly the same as what
the spine
> finder said. And, once he had found them by measuring actual
stiffness, he
> did find FLO in the NBP and spine planes. But yes, they wobbled all
over
> the place in the fake N-S plane that the spine finder found.
>
> Hope this addresses your question.
> DaveT
