Walter & Group............
From Steve Hollensed:-
Gordy,
A few comments about "accelerated acceleration".
First, from a science perspective it is incorrect. Acceleration
quantifies the RATE of change in velocity. Velocity (or speed without
direction) quantifies the RATE of change in position. Rates describe how
fast something is happening per unit of time. So if we use the term
"accelerated acceleration" we would be implying the rate change of a
rate change - which is nonsensical. The words increasing, decreasing, or
constant are appropriate descriptors of this RATE of change in velocity.
In other words, the RATE at which something (including rod tips) changes
position can increase, decrease, or remain constant.
Second, I think we have good congruence between the casting concepts of
SLP of the tip and constant acceleration. Constant acceleration produces
constant forces and without a constant force I think it would be hard to
maintain that near SLP that we talk about. I find my thoughts on this
point difficult to put into words, but in other words, it seems easier
to "paint the ceiling" if something is pulling back on the rod tip in a
nice, even, smooth manner as opposed to a variable or jerky force
pulling back on the rod tip.
Third, only a machine would be able to produce truly constant
acceleration when measured with the resolution that the SCA has. I think
those machines are named Steve Rajeff, Bruce Richards, and Paul Arden. I
am sure there are more casting machines out there, but those are the
best known casting machines that I have seen.
Hope this helps some.
Steve
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Steve ...
Helps a lot.
It was this thought along with Bruce and Noel's findings using the Casting Analyzer which prompted me to withdraw my frequent use of the term, "accelerated acceleration" even though intuitively it had seemed to make sense. We've all learned a great deal in the past couple of years about this stuff ! You and our other engineering, physics & mathematics folks deserve credit for teaching us.
Gordy
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Bruce Richards comments in Walter Simberski's text. Bruce's comments start with, ******* and I hightlighted them in bold red letters: -
Gordy - I expect that the near linear acceleration provides a similar
purpose to always adding a bit of
drift to your backcast. As long as you are drifting you can't creep and
drifting doesn't hurt your cast.
You also can't creep if you come to a rock solid stop but even the
slightest waver could result in a
tiny bit of creep. Eventually this would become part of your muscle memory
and would become a
hard habit to break.
Now for the constant acceleration thing. If we had dedicated use of a
casting analyzer some
of us could eventually get to the point where our acceleration was 100%
constant, even as different
muscle groups came into play during the stroke, but this would take a lot
of practice. If our goal
was to have constant acceleration that would mean those of us who couldn't
get to perfectly constant
acceleration would have little bumps and valleys in our acceleration graph
in our attempt to be constant.
Each bump represents an accelerated acceleration followed by a
decceleration. Valleys would be
a decrease in acceleration followed by increase in acceleration. Each
decceleration represents a slight
unloading of the rod as well as a change in the path of the rod tip. Each
time this happens we are
causing bad things to happen to our cast.
*****In analyzing thousands of casts I could count on both hands the number
of casts we've seen where acceleration decreased before the stop, and these
in very inexperienced casters. In 99+% of the casts, acceleration increases
from the beginning of rotation to the stop. Certainly what Walter describes
is accurate, but in real life, it just doesn't happen. What we see over and
over is increasing acceleration from the beginning of the stroke to the
stop, but how the acceleration is made varies considerably.
The easiest way to avoid the bumps and valleys is to go for an increasing
acceleration. As long as the
increase is smooth and relatively small it does nothing to hurt our cast
because we learn to compensate
for the change in the effective length of the rod with our hand path to
maintain slp.
****Obviously, steadily increasing acceleration would prevent any
acceleration decrease. The best casters learn how to maintain their
acceleration as constant as possible, the best achieve near constant
acceleration.
If the acceleration of the acceleration is too great the caster will lose
control of the cast and this will
manifest in bad loop formation and/or waves in the rod leg.
The happy medium is somewhere in between constant acceleration and losing
control of the cast.
****And this is certainly where most casters end up, but it is not the
ideal. Obviously, the top casters are that due to a lot of practice and
natural ability. The fact that only a small % of casters are able to
achieve near constant acceleration doesn't mean we all shouldn't strive for
it. Few golfers have Tiger Woods swing either (and his club angular
acceleration is very constant I'm sure), but most would like it....
Bruce
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Go back and read what Steve Hollensed wrote, yesterday. This is Bruce Richards' answer to his note on Acceleration:
Gordy, I wouldn't change a word of what Steve has said, except modesty
would have me remove my name from the list with Steve and Paul, they are
both better than I (but please don't tell Paul that!)
Bruce
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Bruce... I'm glad Steve didn't try to include me in that catagory. You guys are all better than I'll ever be !
Gordy
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