Leaders / Acceleratlion vs. rod tip path

Walter & Group...

From Ally Gowans :

Hi Gordy,

 

I forgot to say something else about leaders and flies. Heavy flies have usually possess more energy than the leader can transmit at the extremity of the cast so there are times when the leader turns over the fly and times when the fly straightens out the leader. The heavy brass tubes that we use in salmon fishing fall into that category and without doubt a stiff fluorocarbon leader results in less problems whilst employing these flies.

Best regards,

Ally Gowans

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~``

Ally...   That fits with what I've found with heavy salt water flies. Lots of kinetic energy in those moving flies. 

 In that case, however, the relatively "soft" 60 lb. test nylon mono. butt sections comprising more than 50% of the leader length are still "stiffer" than the end of the fly line and so perform in a manner similar to proprietory stiff nylon mono. of lesser diameter/bulk. 

 These heavy salt water leaders are usually fitted to fly lines in the WF10 to WF12 range.  They have sufficient mass distribution to achieve sufficiently high energy flow to turn over tarpon leaders with large flies despite the lack of what most would consider a sensible taper.  (60# butt section = 6' - 7', "Tapered section" = 1 1/2' - 3' of 40#, Tippet = 2' - 3' of 15# or 20#, Shock (bite) tippet = 12" 40# to 80# Fluorocarbon ).

Sometimes I fish with a leader which has no real taper.... goes from about 6' of 60# nylon mono. to a loop-to-loop connection with 3' of 15# mono. class tippet and then 1' of 60# fluorocarbon shock tippet.  They still turn over well.

Of course it becomes immediately apparent that there is lots of energy left to effect the final turnover of the big SW fly because of incomplete dissipation of energy as the whole thing unfurls.  Soft entry being a less important goal.

When fishing on very slick calm days when the same tarpon are skittish, that system won't work.  For that circumstance I use smaller and much lighter flies and a more tapered leader formula.  Even then, though, I'll not drop below 50# nylon mono for my butt section.  My shock tippet goes way down to 30# Fluorocarbon.  This despite the greater likelihood that a large fish will rasp through it if fought long enough.

Gordy

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

                                                ACCELERATION / ROD TIP PATH  (Followup)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Message answering my comment on yesterday's message on acceleration / rod tip path from Walter Simberski :-

"In # 4. .....   When the rod tip is at the mid point of the casting arc it has to be significantly behind the mid point travel of the butt section of the rod because of rod bend. So at that point the casting arc may well be almost complete."

 

Hi Gordy,

 

With respect to the rod tip at the mid point of the casting arc you make a good point. Here is a very

good example.

 

Basically, if the rod did not bend it would trace an arc (i.e. a section of a circle) but since we want to

follow an slp the rod tip will trace the chord for that particular arc. This means the effective rod length

must be decreasing to the point where the rod tip passes the mid point of the chord. From there on

the erl must be increasing to stay on the chord. In order for the erl to increase we need to reduce the

amount of force we are applying to the rod butt...

 

Thanks

 

Walter

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Walter...    I placed your picture in an attachment.  GREAT EXAMPLE !!!!!

Looks to me like Chase Jablonski making one of his incredible back casts.  His grip isn't easy to see at this range, but it reminded me of his distinct change of grip between the back cast and the forward cast which he uses for his long distance competitive casts.    ( Very loose grip during "hang time".  Tight in proportion to rod load. )

 Gordy

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Walter clarifies his statements on acceleration curves :

Hi Gordy,

 

It appears that I haven't made myself clear in my observations on acceleration. I do not advocate a non-constant

acceleration. I thought I was making it clear that constant acceleration was not only desireable but necessary for

a number of reasons. However, we also need to look at the boundary conditions, i.e. does the rod behave differently

at the beginning or the end of the casting stroke. I haven't seen anything that we would not expect at the end of the

stroke but the idea that the rod can "kick back" at the start of the cast and the affect this can have on the cast is

very well described by Don Phillips in his book, "The Technology of Fly Rods", on page 87.

 

Phillips tells us that the amount of what I call kick back is dependent on the amount of force that is applied at the

beginning of the casting stroke. I believe that the action of the rod is also a contributing factor. Obviously a human is not

able to make a broom stick kick back because a normal human is unable to even make a broomstick bend noticeably

with a casting stroke. On the other hand, a very noodly rod will be prone to kick back and the more noodly the rod the

greater the kick back. Also a rod that is full flex in nature is going to have a more pronounced kick back then a tip flex

rod. I find it fairly easy to make my 6 wt, 9 ft, TCX kick back a foot or more. I can only surmise that a lighter rod with

a slower action can kick back 2 feet or more with little effort.

 

Does this phenomenon actually happen during real life casting? I have seen one case where this phenomenon

was captured on film. It required the use of high definition, high speed still photography to capture the kick back.

The cast was also captured on video simultaneously and I reviewed the video a number of times without being

able to spot the kick back that was obvious in the still photo.

 

So to make my view clear - I think that for the majority of the casting stroke constant force/acceleration is the most

efficient means to make a casting stroke. I think a smooth transition from zero force to the constant force used in the

majority of the casting stroke is a good thing as it ensures that we don't experience kick back irregardless of the rod

characteristics or distance being cast. This transition phase in my opinion is on the order of 1 or 2 degrees, i.e. until

we have the rod tip moving in the direction of the casting stroke for most casts. Even when casting with a very noodly,

full flex rod for maximum distance I doubt if the transition phase is ever more than a few degrees of rotation. This initial

start up phase is a very small percentage of the casting stroke. If we sustain this start up/transition phase for more

than a few degrees of rotation we end up with waves in the fly line and this will result in tailing loops after the loop

forms.

 

Thanks

 

Walter

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 

Walter....  You knew full well you would light a fire with your analysis.  You rattled Bruce's chain. 

 

 Putting "fire in our bellies" helps us learn !

 

Well done.        Gordy

 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

From Aitor Coteron :

Hi Gordy,

Another intersting issue is that in absence of amosphere a lead ball, an elephant and a feather, when dropped from the same height, all three reach the ground at precisely the same time.

　

Regards,

Aitor

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Aitor ....      Agree.   (Love to see that experiment done.)    G.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

From Jim Bass :

Gordy Thanks for the story every now and then it does a soul good to look back.

 

 I also learned a trick to keep a dry fly from sinking when casting in CAC style tournaments.  Don't know much use for it other than gee-whiz info. I learned it from a fellow from Kansas City his name was Steve Aleshi, Steve told me to run the ember of a cigar around the very end of the hackle which would cause an air bubble where the feather was scorched. I still have one of the flies' we used in the tournaments.  With this information and $5.00 you can get a cup of coffee.  I need to revert back to my teenage now and then days.

 

Thanks Jim

 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Jim...   Not sure that would be "legal" for ACA tournaments.  There, the idea is to have all competitors use identical flies which are purchased from approved sources.  Once altered in any way, I suspect it would not "fly" with the judges.   I don't know if they even allow spray- on fly floatant.  G.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Attachment: midpoint.jpg
Description: JPEG image