Fwd: Acceleration

Folk, wasn't sure I should frowarded in case Gordy had already sent it to you; if so my apologies, Jerry

Note: forwarded message attached.

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• Subject: Acceleration
• Date: Tue, 13 Jun 2006 11:41:59 -0400

Jerry,

 ol Al....

Need be no confusion, here.  I look at it this way :

 

1.) The casting analyzer does only one thing.  It measures angular change at the rod but...PERIOD.  It does NOT measure translational movements at all.  New versions of the future will do both....but Noel and Bruce have not yet developed it to that degree.

 

2.)  What is important, is the acceleration of the rod tip.  Secondary is the acceleration of the casting hand both in translational and angular modes.  Obviously this is needed in order to make the tip do what it does.

 

3.)  This acceleration of the rod tip is NOT constant, but rather, UNINTERRUPTED acceleration which is always increasing throughout the stroke.

 

4.)  To be more exact, it is constantly increasing acceleration.....or : ACCELERATED ACCELERATION since the RATE of acceleration is ever increasing out to an (almost) stop.

 

Gordy

 

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Sent: Monday, June 12, 2006 5:59 PM
To: Allen Crise
Cc: bwrichards@xxxxxxx; Gordon Hill
Subject: RE: quiz 6/12

Hmmmm, the text part of this message perplexes me.  Is Gordy saying that the acceleration is not uniform?  What acceleration is he talking about?  We need to differentiate between tip acceleration (linear), or rod butt translational acceleration (also linear), or rod butt rotation (angular acceleration) before we can come to an agreement on this statement.  I think that Bruce and Noel’s analyzer has fairly conclusively shown that the elite casters have a VERY constant angular acceleration of the rod butt.  The angular speed (in deg/sec) increases very smoothly and linearly on the graph from the SCA, it should NOT be a curve or have inflection points in the line.  Bruce? 

 

When I did my frame-by-frame analysis in Alaska, the rod tip acceleration was also quite uniform from start to finish on the very best casts.  

 

Regards -- TAM

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Howdy casters.

  a Gem from  My Gordy file:

 

I see xxxxx's position, but he isn't clear on it.  We all teach "start slow and end fast"....or "loading move followed by a power snap".....whatever one wishes to call it.   Then we go and teach that we need "constant acceleration to a stop".....well, the best casters don't have CONSTANT acceleration to a stop since the acceleration curve is that of ever increasing acceleration at an escalating rate. (The acceleration increase is greater just prior to the stop).  Thus, more correct terminology would be the use of the words: UNINTERRUPTED increasing acceleration to a stop. 

 

Therein lies the crux of the matter.  For you don't have uninterrupted increasing acceleration to a stop if you creep and then stop before finishing the stroke, NOR DO YOU HAVE IT IF YOU CREEP AND THEN ACCELERATE QUICKLY EARLY IN THE STROKE WITHOUT A DEFINED STOP.  One way or the other, you just don't end up with a smooth forward accelerating stroke.

 

 

In your own word define these two term.

Creeping?

Drifting?

What is the effect of each or the lack of in the cast?

 

ol Al  

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