Thanks!
Now that I have a bit more time I can give you a
bit of overview of what Server has to say.
I don't think Server would mind my discussing the
content of the paper with you because
he has already revealed some of it through your
discussion group. For now I prefer to
keep the discussion between us rather than the
larger group because I want Server to
release his paper first so he gets full credit
for it. I would like to discuss it with you though
because I want to get a fresh view and I've
always found you to be both unbiased in your
thinking and knowledgeable and interested enough
to understand this stuff very well. Server
has asked me to review the paper once he has it
prepared and I feel quite honoured about that.
I intend to take my reviewer's duties very
seriously so any feedback you have would be
greatly appreciated.
The gist of the matter is that what we call the
stop has nothing to do with unloading the
rod or providing efficient energy transfer from
the rod to the line. Server will be discussing
things from the point of view of structural
dynamics. He gave me a bit of an overview in this
area but the fact is that basic physics is
sufficient to understand most of it.
We load the rod by pulling it (i.e. providing
force) against some form of drag. The rod will bend
until the amount of pull, or force, balances the
amount of drag. Drag comes from the inertia of the
line, some air resistance against the rod, and
whatever friction there is between the line and
whatever media it resides in or on (i.e. drag for
line resting on water is much greater than line
being false cast in calm air). Static friction is
usually much greater than rolling or dynamic
friction, i.e. to get the line moving it takes
more force than to keep it moving so during
false
casting the amount of drag is fairly small and it
results in very little bend in the rod by
itself.
What creates the majority of bend in the rod
during false casting is when we accelerate
the
line with the rod tip. Remember - Force = mass x
acceleration and since mass is constant
the amount of force is directly proportional to
the acceleration and this force is directly proportional
to the amount of bend in the rod, i.e. lots of
force equals lots of bend, minimal force = minimal bend,
and no force = no bend.
The thing to remember here is that no
acceleration does not mean no velocity or no movement of the
rod. Once the rod tip reaches 100 miles per hour
it can continue at 100 miles per hour and the amount
of force required to keep it moving at 100 miles
per hour is just the amount of force to balance air resistance
which is minimal. What this means is that at this
point there is nothing we can do to prevent the
rod from unloading (unless we have some near
super human ability to start accelerating it again).
It's going to unload whether we continue it
moving at 100 miles per hour or we come to a
dead stop.
The amount of energy the rod transfers to the
line during the unloading phase has nothing to
do with
whether we continue on at 100 miles per hour or
come to a dead stop. The things we can do at this
point are to provide a firm base for the rod to
unload against (by keeping a firm grip and with muscle
tension) and to control the path of the rod tip
so that as the rod unloads the tip pulls the line in the same
direction it has been pulling up to that point
and then gets out of the way so a loop can form.
So the stop has nothing to do with physically
stopping the rod. It is about no longer accelerating the
rod once we have line up to the speed we need to
make the desired case.
A few years ago I was fortunate enough to take a
class with Jason Borger at one of the conclaves.
During the class Jason was discussing the stop
and his casting stroke. I know you've spent some
time casting with and watching Jason cast so that
you know that where his rod typically stops on
his back cast is nearly horizontal. Obviously his
rod must unload before that or he would be throwing
the line at the ground on his back cast and we
know that isn't the case. Jason's explanation was
that advanced casters, such as himself, are able
stop the rod and then quickly follow through so
quickly and smoothly that there doesn't appear to
be a stop. He explained that in slow motion video
of his cast you can see the rod unload at the
proper place but that it happens in a couple of
hundredths of second and then he immediately
moves in to his lay back.
Based on the discussion leading up to the last
paragraph I would say that it is more likely that Jason
doesn't actually stop the rod to make it unload.
He gets to the point of max rod tip acceleration (and rod
load) and then simply doesn't accelerate any
more. The rod naturally unloads within a couple of hundredths
of a second at this point but his hand doesn't
come to a physical stop until much later in his stroke.
From a physical standpoint I also think it makes
much more sense that Jason (or anybody for that
matter) would be able to get the rod tip moving
at some desired speed and then allow it to unload while he
begins his layback positioning rather than
getting the rod tip up to the desired speed, forcing it to unload
by physically stopping his hand and hence the
rod, and then getting his hand moving at the exact same
speed again so quickly that I can't see the
transition.
I note that the 5 essentials by Gammel and Gammel
do not mention the stop. There has been a lot
of
discussion about this but perhaps the right
answer is that physically bringing the rod to a
stop never
was a requirement for efficient casting and
that's why it isn't included in the Gammel essentials.
Another minor point here and then I'm done for
now. Once the rod is loaded there is virtually nothing we
can do to stop it from unloading because we can't
continue to accelerate the rod indefinitely during a normal
casting stroke. I watched Mel Krieger do a demo
once where he was able to whirl the line around the end
of the rod kind of like rotating a sling over
your head. I believe he mentioned seeing Lee Wulff doing this as
part of a demo he called "constant acceleration"
or "constant force". I've tried doing the same thing and the
fact is that fly line is so light and limp that
it is difficult to get more than a few feet of line suspended in the air
this way but it
can be done. This is one way I can think of that force could be applied
indefinitely (at least until the
caster got too tired to continue) but for the
most part this "sling cast" isn't of much use for fly casting
purposes.
I suppose I could also end my casting stroke by
striking a wall with my rod while it is loaded and the
wall would prevent the rod from unloading but,
again, this doesn't have much to do with casting. As far as
fly casting is concerned there is nothing we can
do to prevent a rod from unloading once it is loaded.
Talking to Server about this generated one of
those great big "Aha" moments in my head. He
was able to
explain this and a couple of other things that
have been nagging at me for a while. His explanation of the
"stop" now seems so simple that I'm almost
embarrassed to say I didn't see it this way all along but then
science is often like that. It also makes the
so-called "stopless" cast the Sexyloops people talk about
much easier to understand along with some of the
models and data they've provided. At this point
I can't
see any flaws in Server's views of fly casting
mechanics. At the same time it seems contrary
to what
I've been taught as a casting
instructor...
Again - feedback would be greatly
appreciated.
Thanks Gordy.
Walter
----- Original Message -----
Sent: Tuesday, April 14, 2009 1:29
PM
Subject: RE: Off the record
Will do
!
G.
Gordy,
If you get a chance I think you should try
and encourage Server to get his paper written. I think that what he
has to say is important. Feel free to tell
him I said so (or don't if your prefer).
Cheers
Walter