Re: Physics behind the SNAP CAST

Walter....

I found exactly what you describe.

Much more difficult to do either the Snap-T or C with the inflexible broomstick rod than the flexible fly rod.

A little easier to do the C  than the T with the broomstick .... but still not very good.

This suggests to me that Server may be correct when he says that "bounce back" may play a role.

Gordy





On Oct 25, 2010, at 9:16 PM, Walter Simbirski wrote:

> Hi Gordy,
> 
> I can't find my previous stuff on the snap but there is a lot of stuff happening in these casts.
> 
> As you noted it is harder to make a snap T with a broom stick than a regular rod. Did you try a
> circle C instead? I think you'll find it much easier when using the broomstick. Carl Zarelli tells me
> that some people have a preference for eitther the snap T or the circle C while others are comfortable
> with either one. I think that people who like short quick movements prefer the snap T while those
> who prefer longer slower casting motions will prefer the circle C. Another thing I think you will
> find to help the snap T with the broomstick is to observe the path you make with the rod tip and
> also the speed you get the rod tip moving. When making the cast on water we teach raising the
> rod tip initially at 30 degrees - this helps lift the line from the water but when you make the cast
> on grass line stick is less of an issue so try making your initial lift almost horizontal.
> 
> Another experiment using a regular rod is to make a circle cast or a snake roll and note that the
> circle formed by the line increases in size during the cast and also comes towards
> you (actually towards the rod tip).
> 
> We are dealing with a few things here:
> 
> 1. is conservation of energy. I get the line moving in one direction with my initial lift and then I snap
> the rod tip in the reverse direction. The line has energy due to the initial lift but the reverse snap causes
> the length of line in motion to be quickly decreased. This reduces the amount of mass in motion and
> as you know E = 1/2 m * v(squared) so the fly leg accelerates as it gets shorter but it accelerates
> in the direction it was originally moving in - not the direction of the snap. The line appears to be
> cast opposite to the direction the rod tip is moving in or even at an odd angle depending on the direction
> of the snap.
> 
> 2. is constant tension. The snaps and circles are most effective if they are one continuous movement.
> 
> 3. is line follows rod tip. How do I aim my snap cast? We've all seen the demo where the caster has
> the line on the water in front of them and executes a snap that brings the fly to their hand. It's very easy
> to direct a snap by the direction we make the intial stroke which is then followed by the snap.
> 
> Hope this helps. Let me know if this doesn't make sense or if you have any questions.
> 
> I also suggest consulting Kirk Eberhard for his spey casting knowledge since snaps are studied
> in his dh study group.
> 
> Thanks
> 
> Walter
> 
> ----- Original Message ----- From: "Gordy" <hillshead@xxxxxxxxxxx>
> To: "Walter Simbirski" <simbirsw@xxxxxxxxx>
> Sent: Monday, October 25, 2010 8:26 AM
> Subject: Re: Physics behind the SNAP CAST
> 
> 
> Walter...
> 
> I DO appreciate your doing that !
> 
> Not having the physics background you have I felt, intuitively, that that
> might be just part of the answer.
> 
> 
>        Why ?
> 
> Because I went out and made a snap cast using my stiff broomstick rod.  Not
> a pretty result, but it did the trick.  Certainly no appreciable flexibility
> there and therefore no bounce back.  I did consider the possibility of
> hand/arm bounce back, but couldn't recognize it if it indeed occurred at
> all.
> 
> My B'day is on Nov. 22nd.  Hard to believe I'll be 80 !   (I still feel
> young.)
> 
> Best to you and family,
> 
> Gordy
> 
> 
> On Oct 24, 2010, at 5:34 PM, Walter Simbirski wrote:
> 
>> Hi Gordy,
>> 
>> Glad to hear you had a great trip! Aren't you having a birthday around now
>> or did I miss that?
>> 
>> I don't dispute what Server says regarding bounce back but I think that
>> it's just the
>> tip of the ice berg. I did a bit of research on this some time ago. I'll
>> dig it up and get back to you.
>> 
>> Walter
>> 
>> ----- Original Message ----- From: "Gordy" <hillshead@xxxxxxxxxxx>
>> To: "Walter Simbirski" <simbirsw@xxxxxxxxx>
>> Sent: Sunday, October 24, 2010 2:21 PM
>> Subject: Physics behind the SNAP CAST
>> 
>> 
>> Walter...
>> 
>> Just got back from Nantucket and Montauk.   Had great striped bass fishing
>> there !
>> 
>> Soon, I'm going to launch the topic of the SNAP CAST / SNAP - T / SNAP -Z
>> and the SNAP - C.
>> 
>> I'd sure like your thoughts on the physics behind the basic snap cast.
>> 
>> Server feels that it is due to what he has called, "bounce back" as a
>> manifestation of the first vibration frequency mode.
>> 
>> Best,
>> 
>> Gordy=
>