Translation - new thoughts

Walter & Group..........

Several of you have asked for definitions of TRANSLATION and ROTATION.

TRANSLATION:  Linear (straight line) movement of the casting hand and the fly rod tip with no change in the angular positon of the butt section of the rod from beginning to end.

Some casters use lots of translation when distance casting.  It is often called, "drag".  The casting had moves in the direction of the cast a long way while the butt section of the fly rod does not change its angle with respect to the ground.  At chosen point in the cast, the caster starts to rotate the rod. At first this is done along with some translation, then rotation takes over as tranlation ceases.

ROTATION:  Rotatory movement of the casting hand and rod butt with no linear (straight line) movement, yielding change in the angular position of the butt section of the rod from start to finish.    (Al Kyte once used the term, "SWING" to describe it.) (One might consider the word, "TORQUE", too.)

# Almost all casts use both.

# Rotation accomplishes ROD ARC.    (Change in the angular position of the butt section of the rod from the start to the completion of the stroke.)

# Mel Krieger wrote about the concept of the, "VARIABLE ARC".   He meant a combination of translation and rotation.  Although not labelled with these words, take a look at the drawings on p. 13 of his, THE ESSENCE OF FLY CASTING.

The upper diagram shows, not only a short stroke, but very little angular change in the position of the butt section of the rod from start to finish.  This represents a small amount of ROTATION.  Also, note that the rod cork handle doesn't move very far in a linear direction, either.  This represents short TRANSLATION.

Now see the diagram below.  The angular change and wide arc are obvious.  We also see moderately greater linear (forward straight line movement) of the rod handle.  This represents moderately increased TRANSLATION.

Next:  Look at Figure 3.23 on p. 76 of Mac Brown's, CASTING ANGLES.  In Mac's language, TRANSLATION is called, "hand rod path".  The figure on the left has a short hand rod path or, TRANSLATION, while the figure on the right depicts a long hand rod path or long TRANSLATION.  Now compare the angular positions of the fly rod in each diagram.  THEY ARE IDENTICAL.  This means that the ROTATION or ROD ARC is exactly the same for both of these casts.

Gordy

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

Another way of looking at TRANSLATION, from Troy Miller :

We beat this to a bloody pulp a couple years back.  We had some differences in opinion, to be sure.  I think development of a robot similar to Bruce and Noel's, but with the pivot arm mounted to a sled on a track (to provide linear translation) would enable us to really fully analyze an unhauled cast.  Bruce didn't think it was that important, but I think it would more closely simulate the way most casters cast.  I would love to build something like this, if I had the time, money, and someone like Noel to handle the heaviest physics and programming.

 

I consider the translation to be important, not so much for the AMOUNT of loading, but the NATURE of the early stage of loading.  If you attend one of my classes, you'll hear me say over and over, "Try to NOT surprise anything in the system until the stop".  I don't want rod to ever feel anything resembling an impact load upon startup.  For the very reason you mention, rotational movements tend to result in more rapid tip displacement than translational.  Since we need to get the stationary line (high inertia) moving gradually, it just makes sense to use a translational movement that promotes acceleration from zero velocity through medium velocity, and then transitioning to a more rotational movement in order to continue the acceleration from medium to high tip speeds.    Some other effective verbalizations when teaching:

 

• Sweet talk that line into coming with you.  It doesn't like being bossed around.  Once you get it moving, right around here, then you can tell the line "It's fun to fly!" and start pouring the coals to it right up to the stop.

 

• PUUUULLLLLL the line into motion (while demoing an exaggerated translational movement).

 

In my more advanced classes, I explain in detail how the RTP is affected by different casting inputs (body movements) mady by the caster.  This includes both the hand path and the rates of translation and rotation throughout the stroke.  These directly impact tracking -- linear or non-linear.  From there, I provide some strategy concerning WHEN the caster may choose a non-linear tracking to accomplish some desired result.  Most casters and instructors have been browbeat that a non-linear RTP is baaaaaaad.  Sometimes it is.  Sometimes it's the best choice.  Accomplished flyfishers know when to use and SLP and when not to in their fishing.

Regards -- TAM

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

Troy....

Using new words and word pictures to re explain things we've discussed at length, before is a great teaching ploy, both for us who have been in this Group for years as well as new participants.  I learn a great deal this way.

Your words, also address the, PUSH / PULL controversy as well as smoothness of casting very well !

Before I comment further, let's look at a new message from Jim Valle I highlighted a bit of his text in red italics.   G.:-

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

Gordy and Group,

 

I have debated this issue with Bruce, Gordy and many others.

 

My contention has been that it is impossible to have a cast of any type, without Translation.

I have used the roll cast as an example … getting the proper loop requires getting the line moving in the proper direction prior to the rotation, otherwise we all know the resulting pile…

I still believe that the translation does more than just minimize or eliminate slack. I will agree it certainly does that. I also agree with the rotation being the major contributor to the speed of the cast.

 

However,  as I work on spey casts I begin to appreciate a couple additional factors in the cast. Those being Tension and  Momentum. (Al Buhr, "The world is round"etc.)

The momentums within the cast fascinate me but we’ll save that for another discussion.

 

Tension is the important issue that applies to this discussion.

I believe we are overlooking the importance of the “Loading Move” (Joan Wulff), which I am now learning really  tensions the entire system prior to rotation.  This certainly eliminates slack however through the acceleration during  the translation portion of the stroke, (although some consider this relatively slight), the rod is certainly Loaded … and in my opinion more than just a little…( admittedly the rotation will add more load over a very short time period… equating to speed !!!), but without the translation tensioning  the rotation alone …no matter how fast…. will result in a circular path of the tip.  

Now an argument can be made that it is possible to make casts(esp. single hand) with only the wrist. That is true. However I would submit it takes an experienced caster to control the rod tip through the rotation and that control is a form of translation   which also requires maintaining the tension (or pre-tensioning) throughout the casting sequence. In other words the line controlled tension from the prior pick up or backcast.

 

When I look at the magnified action and reaction of a longer rod and line in a spey cast it is easier to see and feel the tension. Look at the loading sequence in any spey video and through the lift, circle up and forward stroke portion of the cast the rod load is absolutely essential  and apparent if done correctly.

Maybe we can get Al Buhr, Ally Gowans or Dennis Grant  or other spey casters to comment on the subject.

 

My thoughts anyway,

 

Hope this helps,

Jim

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

Comments:

My take on TRANSLATION is that it is an action which fits in the gray area in between substance and style.  I started thinking about this a couple of years ago, when Dennis Grant came up with a list of many things which can be seen as residing in this never-never land.

I think Troy is correct with his way of describing it.  I, also, feel that Jim is right in that all efficient casts have some translation even if admixed with rotation.

His message on Joan Wullf's, "loading move" is interesting.  I see this move as starting with a tiny bit of loading resulting from pure translation followed by greater load as the rod bends further in response to an admixture of translation and rotation, melding seamlessly and smoothly into maximum load as rotation takes over completely.

As this progresses, we go from zero to maximum tip velocity as smooth, CONSTANT acceleration for maximally efficient casts. 

My suspician is that Bruce will slide from his former position that it is an unimportant feature of the cast.  He has recently demonstrated with the help of the Casting Analyzer, that in making a long cast, one is more likely to have a better SLP of the rod tip with tighter loops when rotation is delayed by virtue of the use of translation prior to it.

It appears to me that the longer the cast, the more the use of translation can help.  Having said that, I know that some, "supercasters" such as Steve Rajeff and Jerry Seim can achieve astounding distances with the use of very little translation.  This, while it can be done, requires precise timing combined with strength which most casters don't posses.

Joan has taught that for very short casts, you need little or no, "loading move".  As I study these short casts, I see less need for translation, either.  (The circular path of the rod tip with a 20' cast made with almost pure rotation, is blunted, though not eliminated by rod bend.)

Jim has been doing lots of two handed casting with long rods, of late.  I can see that he is teaching himself new ways to look at these concepts as they become  magnified by the length of his weapons !  This may well be why he calls for  comments by Dennis Grant, Al Buhr & Ally Gowans ..... all experts with the two handed long rods.

Gordy

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

Gordy I hope all is well. 

In my opinion translation relates directly to stroke length (where as rotation relates to the casting arc).  The more translation one has in their cast the longer the stroke length hence translation and stoke length are really one in the same.  By virtue of this the translation or stroke length most definitely contributes to maintaining the SLP as Walter previously said. We are all familiar with the mantra short line short stroke – long line long stroke.  As the amount of fly line being cast increases a longer translation (or casting stroke) is required to give a longer period to smoothly apply the increased power necessary to make the cast. Of course we must also add a wider casting arc (more rotation) in order to keep the straight line path of the rod because of the deeper rod bend caused by the increased amount of line. Translation alone without proper rotation would result in casting tailing loops since the rod path is a concave one without the assistance of the rotation (wider casting arch) to straighten the path out.

In regards to slack I also agree with Walter however I do not feel this is a primary need or purpose of translation but a by product of translation.  While it will help to remove slack, the use of more translation to do so is masking other casting faults and it is they which should be addressed, not compensated for by increased translation.

Just my thoughts…

 

Regards,

Bill Toone

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

Bill .......

In our CBOG Glossary Committee deliberations, we are still debating the exact parameters of the CASTING STROKE.  Depending upon where we see fit to place the start of the stroke some or all of translation may be included.  I don't want to get further into that discussion at this point.

Gordy