Walter & Group.........
From Guy Manning He pretty well puts the issue to bed ...... especially if you read his post script written after he had already sent this .. My brief comments in bold red italics.:-
Gordy,
I
have felt for a couple of years that these discussions about translation and
rotation were lacking a better frame of reference for determining which motion
we were addressing. Take Walters question as to whether one can pick up 30 or 50
feet of line using only rotation. The answer is absolutely yes, depending on
your frame of reference.
If
I lock my wrist and elbow and only use the shoulder joint to create motion then
it could be said that I am only rotating at the shoulder. Others may say that my
wrist and elbow are translating. Which is correct??? They both are, it depends
on your frame of reference.
When
doing motion studies in sports they do not just look at the club, bat, racket,
etc. They are looking more at what the joints of the body are doing to allow the
muscles to be used in the most efficient manner. This gives them a way to
determine how the power is applied and the body parts are used during that power
application. Shouldn’t we be doing the same here? It is not the rod that is
creating the motion, it is the casters body. (Now some will say that this then
becomes a Substance/Style argument but I don’t think they can be that easily
separated. There was a good deal of discussion last year on the on Paul Ardens
site just on that topic. There were enough thoughtful arguments showing how
style and substance become intertwined and dependent on each other to convince
me that this is often true. Having said that it is still Al Kytes construct is
still valid as a teaching tool and I still use it as such. It is only in high
level conversations that I may disagree with a black vs. white “Substance vs.
Style” argument.)
Here
is an animation of a cast that is pretty close to what I do at normal distances:
http://i112.photobucket.com/albums/n163/grhen/cast/caster-anime2.gif
In
my normal 40-45 foot forward cast I use 3 joints in rotation to make the cast.
My shoulder joint pulls the upper arm down so that my elbow is now coming down
towards its normal resting position along side of the trunk of the body (elbow
just forward of the centerline of the side of the body). This in turn pulls the
lower arm down changing its angle from approximately vertical to approximately
15 to 20 degrees above horizontal. It is only during the last 30% or so of
this motion that I add wrist rotation. All 3 rotary motions stop at the same
time creating the “sudden stop”.
So
in a sense I have used only rotational motions to make this cast. But if you
track the wrist joint and the elbow joints you will see that they have also
translated because of their position further out on an “articulated lever” that
is the arm. The only joint here that truly rotates is the shoulder, and that is
only because I am standing still and not rocking.
During
this discussion mention has been made of maximum road load occurring at a
certain point, in fractions of a second, prior to RSP. This changes with the
distance being cast so I don’t think we can make flat statements or rules about
this. You have to remember that Bruce is making measurements for a given length
of line which requires a particular tempo that will change with line length.
Here
is an animated gif of Renee Gillibert casting a shooting head in
competition: http://i112.photobucket.com/albums/n163/grhen/cast/renee.gif
The
cast itself lasts for 10 frames, the next four add graphics and pause to the
animation.
I
realize the graphic markings are hard to see in the last few frames, but what I
did was to strike a line from the wrist from the start point and end point of
the stroke (long red horizontal line). I then looked for the frame where the rod
was bent furthest into the butt. At that point I marked a line along the butt of
the rod intersecting with the wrist path line (short red vertical line). The red
dots show the track of his wrist during the forward stroke.
Now
counting frames you will notice that in the seventh frame the blank is bent
furthest down the butt of the rod. This happens to correspond with a point along
the wrist path where the rod is perpendicular to the wrist start/stop path. This
also happens to correspond with where Renee first applies wrist rotation. Any
motion after that does not contribute to the bend in the rod since it is in fact
unloading. So approximate measurements show that rotation begins
approximately 70-75% of the way through the entire forward motion.
Now
here is Jay Clark at the same competition. http://i112.photobucket.com/albums/n163/grhen/cast/jay.gif
I
happened to put the lines in sooner on this animation so things may be easier to
see. It was also taken with a different camera so I was able to use interlacing
to create 2 rod tacks per frame (don’t’ ask how, it just worked out that way).
With this animation the blank is bent furthest down on the 11th
frame. This also corresponds to a point where the rod goes perpendicular to the
wrist start/stop path. And as with Renee it corresponds to when Jay first
applies rotation. So again everything after that is a rod being unloaded. You
will notice that in this case all unloading takes place in the last 15% or so of
the entire forward motion. (Who casts farther? That depends on who is casting
better on any given day and the price of eggs in China)
When
I video my self casting only 40-45 feet the following occurs which are contrary
to assumptions that might be made about the two animations above: Rotation
starts about 70% of the way through the stroke and the rod never reaches a point
where it becomes perpendicular to the wrist start/stop path which is quite short
in this instance, maybe16 inches. My point is that we should be careful to make
assumptions based upon a small sample of observances.
Guy
Manning
FFF Master Certified Casting Instructor
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Gordy,
I
seem to have misread Walter question. He was asking if the line could be picked
up with “translation” only, I read it as “rotation” only, so some my
comments from my previous email may be out of sort with the
discussion.
FFF Master Certified Casting
Instructor
Moderator FFFCCI Yahoo
Group
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`
Guy.... You make some good points here, anyway.
Bruce Richards and I both noted that even when we do hand casting, there is translation of the hand, BUT the forearm becomes the, "rod" and lots of rotation occurs there.
I did have some trouble activating the links to the pictures, though. Had to try several times.
Gordy
