Pages: [1] 2 3 4
Author Topic: Talking about casting...  (Read 24385 times)
riveraddict
Sr. Member
****
Offline Offline

Posts: 418


View Profile
« on: March 08, 2013, 11:34:01 AM »

   Things to do when the local flow is and has been frozen solid for months. Do a search on "Skagit Casting" and note the interesting results. In particular, it seems that a certain Euro Spey site has some rather intrigueing opinions, especially as regards Skagit. Different strokes for different folks as the saying goes. However, some of their opinions have me wondering... after all, I am always interested in learning. So, questions! I would like to hear your thoughts/opinions!

   If a 9' flyrod is placed into a fixed vertical position, a 30' piece of flyline tied to the tip and then that line stretched out by the free end until the rod bends significantly, then that line is released, does the line get "cast"?

   If a 9' 2x4 is used in place of the flyrod, will the line get cast?

   If the 9' 2x4 is given an axis point 12" up from the bottom and a bungee cord is attached to the very bottom of the 2x4 to: stretch out when the flyline is pulled and contract when the flyline is released. Will the line get cast when released?

   Is a flyrod a lever or a spring? 

   
Logged

StillWading
Newbie
*
Offline Offline

Posts: 41


View Profile
« Reply #1 on: March 08, 2013, 12:41:40 PM »

Haha!  I think i came across that site when I started SH casting!  I believe a rod is both.  A lever; that it multiplies the distance of arm travel, and a spring; in its ability to store and release energy.  So, as both characteristics are present and employed, both rod quality and technique are important to execute a cast efficiently.
Logged

middlecalf
Jr. Member
**
Offline Offline

Posts: 95


View Profile Email
« Reply #2 on: March 08, 2013, 03:38:48 PM »

I agree with Stillwading.  With regards to your last scenario Ed, the bungee is just another spring introduced into the system.  It's funny how, I think unitentionally, there's a focus on the "extreme cases" when we try and figure out this casting stuff.  Your examples are what I'd call "extreme," or more accurately, boundary cases in that you only get one option or one way, either a fixed rod that does bend, or a fixed 2x4 that doesn't bend, or a hinged 2x4 with another spring (bungee) attached to it.  In reality for us, we have a bendable rod (some more than others) that is hinged due to our hands/arms and that is leveraged by our arm motion.  So our "system" allows us to adapt to the conditions we're given, that being the line, type of cast, what we're casting, length of rod, height of person, depth of wading, etc etc etc.  And given these constraints, we adapt our casting to best achieve our goal(s) - which could be a long cast, really tight loops, minimal arm movement, etc etc., or any of these in combination or even all of them combined.  And in that adaption, we, being the creatures of organization that we are, call it Skagit, or Scandinavian, or traditional, or etc. etc., or in my case sometimes, El Stinko Crappo - LOL.

(I think in the last case the system will act like a trebuchet - but only if the fly is lit on fire before it's launched Grin)
« Last Edit: March 08, 2013, 03:40:25 PM by middlecalf » Logged

riveraddict
Sr. Member
****
Offline Offline

Posts: 418


View Profile
« Reply #3 on: March 08, 2013, 04:31:07 PM »

   I agree with both you guys in that it is a bit of both... rod bends and stores energy, then releases that energy by unbending... a spring action. However, the rod is physically manipulated for casting by "us" with a levering action (speaking of doublehanded casting). At least that's my laymen take on the process. So, are either of you guys accredited Physicists or Mechanical Engineers? Anyway, if you've got a lot of spare time, check out the sexyloops site and read the thread having to do with sustained anchor. It might raise some questions about how different folks interpret casting, will certainly bolster the notion that some factions of European culture stick very closely with what's traditional and are very, very prejudiced to "new stuff", and at the very least it should provide some entertainment value! 

Middlecalf,
   An interesting concept that, lighting the fly on fire gig. Might have to give that a try!!!

OK, more questions.

   Fly rod, with 30' of line laid out on the water inert. Perform one backcast and then lay the line back out front onto the water.

   Fly rod, with 30' of line laid out inert on a dry, shortly trimmed lawn. Perform one backcast and then lay the line back out front onto the grass.

   Was there a difference in the amount of resistance felt in pulling the line out/off of either "medium" for the backcast?

   If so, did that "difference" affect in any way the accomplishment of the forward cast?

   
Logged

riveraddict
Sr. Member
****
Offline Offline

Posts: 418


View Profile
« Reply #4 on: March 08, 2013, 04:43:36 PM »

   Sorry, I put up some bad info! Going to sexyloops and doing a search is not the route... doesn't seem to work out. Instead, do a Google search using "sustained anchor". Then a whole plethora of hits come up, just look for the one referencing sexyloops and that will be the one... 5 pages of interesting comments.
Logged

yuhina
Full Member
***
Offline Offline

Posts: 156


View Profile
« Reply #5 on: March 08, 2013, 05:41:00 PM »

Apparently the Snakie did not like you!!  Grin 
I wonder if you scooped  his fish after his run or what?!

Sexyloop is a very interesting place...lot's of mechanic guys and willing to do experiments just to test out ideas... I actually quiet admire their scientific spirit! But the average people there are no different than other websites. few has mechanic engineering backgrounds and keening in casting mechanic. A funny story I would like to tell...  a guy posted a topic about two handed casting and how the leverage related to rotational center... it just happened that I am very familiar to that subject, it was fun to watch the discussion/ debating going... up to 33 pages!.  a guy already mentioned the answer when it reached the page 8. A lot of certified instructors fail to answer the question... so I guess 5 pages is not too bad!! Tongue   If I have time I will dig out that thread and post them here...
Logged


middlecalf
Jr. Member
**
Offline Offline

Posts: 95


View Profile Email
« Reply #6 on: March 08, 2013, 06:05:38 PM »

Will definitely hit the sexyloops link during cocktail hour tonight!  In engineering, there are "Professional Engineer" certifications for some disciplines, usually civil and mechanical, and it's necessity for getting/having a job varies state-by-state.  The PE exam is a multi-day serious brain dump, but being an Aerospace Engineer (now retired), I didn't need to take it or have a "PE" certification to get a job in the aerospace industry.  Being an AE, I had a lot of classes that dealt with mechanics of motion, but I have to tell you, casting (fly) and understanding it's mechanics is very complex, and even harder to adequately define and describe in mathematical terms or engineering terms.  In many ways your explanations are very sound and I've enjoyed the cause-and-effect explanations.

With that said, wrt your new questions, I'd venture that pulling the line off the water will be a bit "trickier" because the tension and release on the line will be a bit more "random" than with the dry short grass (I'm assuming you aren't using a grass leader with a lot of knots, etc).  But once the line is released from the surface and is moving rearward into the backcast, if the rod is bent the same distance at the point it reaches its maximum bend for both cases (and both lines have stopped moving rearward), and everything else being equal (line position, wind, rod orientation, forward cast stroke, etc etc), both lines will cast the same and achieve the same distance.  But in reality, because of that more random release pattern of the waterborne case, most likely the backcast won't be the same (line will be move faster or slower, won't flex the rod as much or will flex the rod more, horizontal postion will be different, etc etc) one would have to compensate in the forward stroke (timing, acceleration, tip travel, etc etc) to get the lines to cast the same and achieve the same distance.  (Note all of the "etc etc" - that equals 'complex' - LOL).  And I guess that's what makes this all fun!!
« Last Edit: March 08, 2013, 06:08:19 PM by middlecalf » Logged

yuhina
Full Member
***
Offline Offline

Posts: 156


View Profile
« Reply #7 on: March 08, 2013, 06:15:24 PM »

   I agree with both you guys in that it is a bit of both... rod bends and stores energy, then releases that energy by unbending... a spring action. However, the rod is physically manipulated for casting by "us" with a levering action (speaking of doublehanded casting). At least that's my laymen take on the process. So, are either of you guys accredited Physicists or Mechanical Engineers? Anyway, if you've got a lot of spare time, check out the sexyloops site and read the thread having to do with sustained anchor. It might raise some questions about how different folks interpret casting, will certainly bolster the notion that some factions of European culture stick very closely with what's traditional and are very, very prejudiced to "new stuff", and at the very least it should provide some entertainment value! 

Middlecalf,
   An interesting concept that, lighting the fly on fire gig. Might have to give that a try!!!

OK, more questions.

   Fly rod, with 30' of line laid out on the water inert. Perform one backcast and then lay the line back out front onto the water.

   Fly rod, with 30' of line laid out inert on a dry, shortly trimmed lawn. Perform one backcast and then lay the line back out front onto the grass.

   Was there a difference in the amount of resistance felt in pulling the line out/off of either "medium" for the backcast?

   If so, did that "difference" affect in any way the accomplishment of the forward cast?

   

Ed, your open minded approach is always admiring! very cool thread!

I like the question! I guess the water friction will make a big difference in terms of feel... I also agree middlecalf said that our body will adjust for the difference... As I sensed that the water friction probably will make the lift much easier for caster to load, compare to the "slippery" grass...
Logged


riveraddict
Sr. Member
****
Offline Offline

Posts: 418


View Profile
« Reply #8 on: March 08, 2013, 10:50:50 PM »

   I have heard the same basic thoughts, by other peoples educated in mechanics or physics, that fly casting is so multi-faceted in its mechanics, as to be very difficult to "quantify" in any singular aspect of explanation. However, I do believe that the functions of flycasting can be effectively explained to most "regular folks" by using simpler descriptive means, that though not necessarily absolutely "correct" from a true/pure mechanics/physics context, do convey an imagery that is successful. I guess what I'm getting at, is that I don't understand gripes about referring to a flyrod as a "spring" for teaching purposes. It's a simple description that seems to get the right point across and does so far better than saying "a flyrod is a quantum Newtonian momentum displacing lever hybridized with a Gallilean incrementally angularly, centrifugally deflective, energy transferring synthetic tube device! Note: the aforementioned device is a totally made up by me, string of words.

The cast from water, from grass bit... what I'm looking for there is: does the increased resistance to line movement provided by water amplify the bend of the rod and thus contribute to loading the rod for the backcast? Does not the same cast on grass require increased acceleration of the rod into the backcast or the addition of a haul on the backcast in order to achieve the same degree of initial rod bend? If so, is this not an indication that a significant portion of rod loading can be produced via water resistance and that this could in fact be thought of as "waterloading". I ask this because I get an inference from that sexyloops thread that waterloading isn't a valid process?          
« Last Edit: March 08, 2013, 10:54:30 PM by riveraddict » Logged

yuhina
Full Member
***
Offline Offline

Posts: 156


View Profile
« Reply #9 on: March 09, 2013, 09:23:18 AM »

 I guess what I'm getting at, is that I don't understand gripes about referring to a flyrod as a "spring" for teaching purposes. It's a simple description that seems to get the right point across and does so far better than saying "a flyrod is a quantum Newtonian momentum displacing lever hybridized with a Gallilean incrementally angularly, centrifugally deflective, energy transferring synthetic tube device! Note: the aforementioned device is a totally made up by me, string of words.

Ha... too funny Ed...

In my mind, there is no doubt that a good analogy will reach a better understanding. I was baffled why some of the people didn't like the "spring" analogy? I like the spring analogy a lot, probably because I did a lot "bow-and-arrow cast" when fish for trout in the NE.  

re-read the sexyloops thread, some people seems don't like the idea of "anchor load the rod" ... however, people all agree roll cast only can be taught on the water...    
Logged


riveraddict
Sr. Member
****
Offline Offline

Posts: 418


View Profile
« Reply #10 on: March 09, 2013, 11:04:39 AM »

   OK, here's another "interesting for discussion" subject... "the upper leg of the D-loop is what loads the rod". A youtube example of this line of reasoning is around somewhere, but I can't remember the link. Anyways, it is basically a length of bead chain laying straight on a table, one end - end A - hanging slightly over the edge, the other end - end B - stretched towards the middle of the table. Next, the length of bead chain is "folded" at about a 45 degree angle so that end B just touches the edge of the table. At that point, the length of chain going to end A is analogous to the upper leg of a D-loop, while the section going to end B is analogous to the bottom leg. Next, when the handler takes their fingers from off of the bead chain section after manipulating it into that folded configuration, end A starts to fall off the table and subsequently pulls the entire remaining length of chain off the table. I could not get the audio on this when I watched it, but I'm assuming that the inference is that since the bottom leg of the chain is offering no resistance to the pull of the upper leg that it therefore cannot be contributing to rod loading. It's an interesting illustration for sure, but my common layperson mind wonders about the absence of backward momentum that seems like would be present in an actual D-loop mechanism and also has to ask that if the bottom leg has no part in rod loading, then why does the shape of a D-loop have such a great influence on the resulting performance of the forward cast? Anyone care to comment?   
Logged

yuhina
Full Member
***
Offline Offline

Posts: 156


View Profile
« Reply #11 on: March 09, 2013, 01:18:09 PM »

https://vimeo.com/39907238

Ed, is this video you are talking about? this guy is from sexyloops...
Logged


middlecalf
Jr. Member
**
Offline Offline

Posts: 95


View Profile Email
« Reply #12 on: March 09, 2013, 06:34:50 PM »

Wow, love this discussion.  Ed, I completely missed your point on the earlier question wrt the backcast, I thought you were looking at the influence to the forward cast.  Definitely line tension caused by water contact (or let's just say water load) occurs for the backcast in your example.  There is also line and rod inertia loading the rod.  Have you seen Blue Charm with Ian Gordon?  He has a great example of a roll cast that shows most of the rod loading coming from the water.  But this is all for the backcast.  Applies to the sweep "cast" of the double spey, the snap-t/c/....  Not so much for the poke depending on where the poke is and how the line is pulled off the water.  What I think the sexyloop contributors are misunderstanding (I hope I'm not also!!) in your casting descriptions is that you are attempting to carry some amount of the load that's occuring during the sweep into the forward stroke by continuous motion and sweeping circularly through a plane that is from a somewhat horizontal orientation to somewhat vertical.  And that load is due to varying amounts rod and line inertia, water load, and line momentum.  Timing is critical as you know and it is arguable as to how much of this load carries through (and its benefit vs. a normal sweep back - pause- fire motion) and what contributors to that load are still contributing up to the start of the forward cast motion.  Aitor Coteron on sexyloops has some very good videos that show the unloading for traditional spey casts but he doesn't have one for a spey cast involving a circular sweep with continous motion into the forward cast.  His videos do show that in those traditional casts the rod unloads after the set cast and then reloads during the forward cast from rod and line inertia principally, but also from deacceleration of the line moving into the d-loop if the forward cast is initiated before the line stops moving (Ian has a great stop motion look at a single spey and this additional loading is very evident).  There is no water loading in those cases, the water contact at the tip keeps the tip part of the line from being pulled from the water too soon which would rapidly extract energy from the cast.  Once the line is stopped being pulled from the water in any part of any cast "water load" goes away.

On that d-loop thing, the only way to get water tension on the line during the forward cast would be to bascially make it in itself a backcast (a waterborne overhead cast I guess where the backcast starts on the water).  And I actually think I've seen a video of this, can't remember if it was Tom Larimar, might even be Dana on his speypages videos.  Anyway, Aitor has several videos that show that the forward stroke is completed even before the bottom part of the loop in contact with the water begins to move.  I have to think some more on the impacts of d-loop shape (v vs. d), but my initial thought is that it's an indicator of how much line speed is going into the d (or v)-loop, "v" being more.
« Last Edit: March 09, 2013, 06:38:47 PM by middlecalf » Logged

middlecalf
Jr. Member
**
Offline Offline

Posts: 95


View Profile Email
« Reply #13 on: March 09, 2013, 07:05:06 PM »

Did some frame grabs from this video that Mark posted on another thread
http://www.youtube.com/watch?v=efTRwbpiYt8

Frame 1 @ 2:32 - start of sweep.  You can see the initial loading is coming from rod and line inertia (line isn't being picked up yet)

Frame 2 @ 2:33 - well into the sweep, and rod lod is probably mostly due to water load because Ed talks about sweeping at a constant rate (speed), so that would mean acceleration is zero, which means no resultant force due to inertia (but is he really sweeping at a constant rate? Tongue)

Frame 3 @ 2:33 and change - almost done with the sweep, still loading the rod with the water

Frame 4 @ 2:34 - just before forward cast fire, d-loop is fully formed.  The rod is still bent, which means there is still load.  Not much but some.  Hard to grab frames from a moderately slow mo video, better if super slow mo, but this is about the least amount of load during the sweep I can find.  Note the "direction" of the load wrt the rod, it's now in the direction that is necessary for the forward cast.  And yes, "load" is a result of force, which is a vector, which therefore has direction and magnitude.  Since the direction of the load has obviously changed, the load has changed in a strict sense.  But the heck with that, we like to look at bent rods, especially towards fish!  I digress...
« Last Edit: March 09, 2013, 07:14:17 PM by middlecalf » Logged

middlecalf
Jr. Member
**
Offline Offline

Posts: 95


View Profile Email
« Reply #14 on: March 09, 2013, 07:08:54 PM »

And one more frame:

Frame 5 @ 2:34 and change - beginning forward stroke.  Notice increase rod load due to rod and line inertia.  Can't tell from the video if the line is still moving into the d-loop before this, if it is, then there is also some load due to deacceleration of the line.  Deacceleration could also be causing the remnant sweep load in frame 4, as the line is being swept out and around and is carrying momentum from that motion.
Logged

Pages: [1] 2 3 4
Print
 
Jump to: