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If we ignore the occasional urge to recreate so-called classic designs are there any other reasons that we might design a rod with a step down ferrule? You may not cheat by looking in my taper library in Hexrod! (Robin Haywood) OK, here's some food for thought! What if the rods in question were really not made with step down ferrules by design, instead it was like........."well we have a bunch of tip sections that we milled and a bunch of butt sections but they don't really match, hey how about if we use step down ferrules? That would work" ............Nah, that couldn't happen, certainly not at the Dickerson plant. Or could it? (Joe Arguello) I'm having a very bad influence on you Joe. You really must put all these wicked and heretical ideas out of your head and return to worshipping the great classic rodmakers as the living representatives of God on earth. If you don't you will start believing that their tapers can nearly all be dramatically improved and the rest merely significantly. You will then discover that compound tapers produce rods which are both lighter and nicer to fish with and that faster tapers do not mean that the thing will break the third time its used.That will be terrible. You will then be outlawed from all rodmakers gatherings and customers will see you as a maverick. When you have been dead for at least a decade people will be out there wondering whether to buy a new Caddy or try and find one of your least popular rods cheap. Don't come stomping down to Hell trying to find me just to tell me I was right! (Robin Haywood) Might have happened at some of the other plants, but I doubt very much it happened at Dickerson's shop. (Mark Wendt) It might happen at almost any other production operation, but the last place for that attitude would be Lyle Dickerson's shop. You don't know Dickerson. (Bill Harms) Ummm, would Dickerson actually have had any alternative ferrule choice? I'm not justifying step downs in tapers though. If you only have a step down ferrule you build up the butt section, its very easy. (Robin Haywood) Sure, he could have used Super Z ferrules. But his tapers were designed for using step-down ferrules, and were designed with the action that a step-down in sectional dimensions would give. It were no accident. (Mark Wendt) I wonder why. (Robin Haywood) Probably because that was the prevalent ferrule in those days? (Mark Wendt) Yeah, and Super Z's weren't invented till later in Dickerson's career. (Harry Boyd) I suspected as much but did'nt have the chronology handy, only vague recollections of relevent dates. So, Dickersons designs were based on the need to use a step down ferrule and a reluctance to build up the butt sections to fit................were they? (Robin Haywood) Dickerson designed and built all his rods alone in his little shop, and he designed and machined his own ferrules as well. Most makers of his era regarded Dickerson's ferrules as second to none. Super-Z's were developed by Lou Feirabend in conjunction with Nat Uslan's shop, but these did not become available until the late 1940's. Dickerson knew of them, did not like their "bulk," and always believed he needed to make his own step-downs for his own rod designs. (Bill Harms) My instinct is that rodmakers should stick to making rods and machinists should machine what the rodmakers draw. My good friend Luke, who may not be reading this, is more of the polymath persuasion. Its not that I have any objection to diversity but if Dickerson had not made ferrules he would have made more rods, which may, to some, have been a more useful use of his time. (Robin Haywood) Dickerson was a machinist before he got into rod making. I'm sure he had plenty of ways to ensure his machining time was productive. All his tapers were cut on a machine he designed. Had he not been a machinist, or had the bent, he probably wouldn't have been as prolific in rod making as he was, nor would he probably have made the impression on the bamboo rod world as he did. (Mark Wendt) The impression he made on the rodmaking world was solely because of his tapers. These may have been better than most that were then available, but do not compete with what can be achieved today. (Robin Haywood) I'd say it just wasn't the tapers, but the overall design and cosmetics of his rods. Really? Then it seems pretty amazing considering that his tapers seem to be some of the most copied of all the tapers today. (Mark Wendt) I would say that Garrisons tapers are the same or more often copied that any. Even W Cattenach has a Garrison type taper now. Since Garrisons are so distinctive and they all have the same format it may be that they are easier to pick out for me. How would you characterize the Dickerson tapers? (Bob Norwood) Dickerson tapers tend to be a little faster than the norm. Let me paraphrase that - they tend to be more "powerful" than the norm. They also tend to work very nicely for close in work, and they still have the power in reserve to boom out the cast when you need to. They're also great fish fighting rods. I've cast plenty of rods that were either or, but damn few that did both so well. (Mark Wendt) The popular ones like the 8013/4 have a stiff butt with most of the action in the lower 2/3rds of the tip, the top third or so of which spends depressingly little of its life bending. You can predict this just from the taper curves if you know how to compare and contrast different rates of taper. It was a popular way of cobbling up tapers right into the carbon and boron era, and popular because it works better than it looks and better than the even more half baked designs which preceded it. In fact, it even produces a type of taper that would, in a very crude sense, perform the tasks Ritz said he required of his parabolics much better than any of the things that Plantet produced under that name. As a taper form you can improve it no end by leaving the butt alone, increasing the rate of taper of the lower third or a bit less of the tip so that the need for a step down ferrule is eliminated and increasing the rate of taper of the top quarter of the tip so it bends. You don't have to believe me, try it for yourselves before you disagree. (Robin Haywood) The rod works because it has a soft tip for short casts and a strong butt for long casts and look sort of similar to the sir D. But,to me it looks like a strong 5 wt or a weaker 6 wt, what line size do you use? (Bob Norwood) The 8013 is a 5 wt and the 8014 is a 6 wt. (Mark Wendt) In planning to build the 8014, I went ahead and ordered the 14/64th ferrules from Rush River Rods. Now after all of this talk about using step downs and how Dickerson’s tapers were designed for the step downs, what are the consequences of using the Super Swiss style ferrules using the interpolated taper dimensions from RodDNA for the 8014? Does anyone have a set of step downs they would be willing to trade me for the 14/64th ferrules I have from Rush River Rods? (Greg Reeves) I used the similar interpretations in the Hexrod library to no apparent ill effect. You can probably slightly improve on this bit of acceptable bodgery by spreading the swell in the lower part of the tip over about 18''. Heresy, apparently. Dickerson was a God, mere mortals may not argue, just follow mindlessly the works of The great Rodmaker. Round things that hang from the back of, for instance, dogs. (Robin Haywood) It will work. You will have a fine rod unless you do not like Dickersons; it won't be a Payne. (Timothy Troester) Not sure about that, but it will certainly be a very useable rod, and if you look at the curve when casting and playing a fish you will learn how to, improve upon it. (Robin Haywood) I made a Dickerson 7613 with SS ferrules from Rush River & I think it's great. It's really happy with a WF #6, to the point I haven't even tried anything else. It depends on where you fish though. I don't think it would be too good on a small stream though, it's more for big water. (Neil Savage) If you are using the taper from Hexrod online I think a regular 14/64 will work fine. I can't see how a step ferrule would work, there is no step in this taper. Now maybe there is a Dickerson 8014 that is for a step but this one is not it. Maybe someone could give us the correct taper. BTW the 8014 is a Strong 7 wt not a 6 wt, it would probably handle an 8 WF very well (should get some comments on this one). (Bob Norwood) I have 2 different tapers for the 8014 Guide, both mic'ed from original Dickersons. The one was from a rod that list member Jeff Fultz did some work on. He said he couldn't let it get away without lawncasting it. The other taper came from Banjo's (Sante Guillane sp?) Dickerson which he said would throw the entire DT6 or the entire WTF 7. Neither of those were a 7 wt/8 wt but did differ a little in their numbers. (Will Price)
The discussion of ferrule design has still left open the basic question about why most of the old makers built in a taper discontinuity at the ferrules? (Some call this a "taper drop"). In any event it's there -- all you have to do is look at the tapers in Jack Howell's books, which are measured so there is a dimension at each section's ferrule location. (Rich Margiotta) Well I don't think there is as much "discontinuity" in the taper as everybody seems to think. Just look closely at Robert Norwood’s recent mail on Straight Line Tapers having to be "beefed up" below the ferrule to account for the extra weight of the ferrule and still maintain the true nature of a SLT. A 1/64" (16 thousandth) "step" in the taper isn't that much. Think of the taper going smoothly from the tip top toward the butt. Suddenly you stick a 1/4 oz. ferrule onto the taper. And 1/4 oz. is not an exaggeration for some ferrules. Of course you will need "Extra" bamboo to account for the "extra" weight of the ferrule, and all the way down to the butt not just close to the ferrule. I just went down to the shop and weighed a couple of ferrules. #13 Golden Witch field grade = 0.2 oz. #17 Bellinger = 0.4 oz. It seems to me that this supposed "discontinuity" just makes up for the ferrule by beefing up the butt a little. (Larry Swearingen) What you say makes intuitive sense to me. On a slightly different tack, I think stepdowns should really be called ‘step-ups’. I am no engineer, so the following may be a load of codswhollop, but is how I think about stepdowns. It makes sense that one piece rods must be the most versatile, and therefore the ‘best’, in design terms, because the ferrule is not a limiting factor. (Unless the ferrule can be considered to add something positive to the design which could not be added purely in the taper itself. I somehow doubt this.) Consider then starting with a wonderful, smoothly transitioned, one piece, ‘perfect’ rod and imagine having to add a lump of weight (the ferrule) to the middle of it. For the sake of the argument imagine this being quite a hefty lump. Given that the rod’s fulcrum is in the hand, and additional weight has been applied to the rod at a distance from the fulcrum , the rod will necessarily bend more than previously. This change in the bending will necessarily change the action and feel of the rod away from the previous ‘ideal’ design. So how do you get back to that ‘ideal’? I imagine you have to consider where the change in the bending will actually be. It surely has to be only in the section of rod leading from the hand to the added weight – i.e. in the butt. The butt acts like a cantilever from the hand but now has weight added to the end of it and will thus bend more. There will on the other hand be no change in the bending of the tip, because although it also acts like a cantilever, it effectively cantilevers ‘from’ the added weight not ‘to’ it. With no added weight at the end of the tip there is no change in the bending of the tip. (Considered statically, the tip will obviously ‘point’ in a slightly different direction due to the increased bending in the butt, but the actual bending in the tip itself will not differ). I am not sure if this is true dynamically, but I would imagine so? In order to get back to the ‘ideal’ design of the original one piece rod, the additional bending in the butt therefore has to be ‘removed’. The only way to do this is to stiffen the butt. This is best done by adding thickness. The tip must remain the same as there is no change in the bending of the tip. Thus the desirability, in design terms, of introducing a ‘step-up’ in taper from the tip to the butt, when a ferrule is required. ‘Step down’ implies keeping the butt dimensions and thinning down the tip. Whilst the action of the rod could theoretically be preserved in this way, it would result in a change of line weight. (Stephen Dugmore) Agreed, but actually just another way of looking at it. {:>) (Larry Swearingen) Do you need to add cane to compensate for the weight of the ferrule or subtract it to compensate for the stiffness of the ferrule? (Henry Mitchell) Good question, Henry. I think it depends on the type of taper you are designing. If you are making a fast action step down type taper, as others have suggested, the weight is already neutralized by the taper increase, and you want the stiffness, because that's the whole point of the step down. You want the tip to flex, and the butt to be stiff, so you get the fast action. With a parabolic taper, you want the middle of the rod to be stiff, so the taper is swelled through the middle, a super Z type ferrule is used, and the stiffness of the ferrule is no detriment. Most of these tapers are a full 64th thicker than normal at the ferrule, so the weight is carried well. Your question becomes very interesting when considering straight line, progressive tapers, particularly slower action progressives. The idea here is for the bend of the rod to increase uniformly as load is increased, so that the caster can develop a feel for exactly how much power to apply for a given cast. Here the weight and stiffness of the ferrule are detrimental, and should be somehow addressed. Most of us cut our teeth on the Garrison stress curve method, which is in fact, pretty good. However it is based on static weight, and does not take into account the momentum developed by moving the ferrule when casting. I noticed a long time ago that a Garrison taper built with lightweight ferrules seems to have a noticeably improved action. If I were going to build one today with a standard super Z, I would add another .002 or thereabouts to the butt dimensions. The Garrison method does not address the stiffness of the ferrules, in fact, by adding material right at the ferrule, it may increase the stiff spot. Some time ago, before I became an admitted nut case on the topic of ferrule weight, I built a Garrison taper with an oversized ferrule. It caused the rod butt to flex excessively. The apex of the excess bend, however, was not at the ferrule, but rather 6" to a foot from the ferrule. So if I wanted to compensate for the weight with taper, that is where the extra material should go. I think the best approach to the problem is that advocated by Vincent Marinaro. His method of the strategic placement of very subtle swells and valleys along the taper is the only method I have seen that addresses both the weight and stiffness of the ferrule. As always, the devil is in the details. Where do you put the swells exactly, and how big should they be? More questions than answers, I'm afraid, but I do think Marinaro was on the right track, and his rods cast much like one piece rods. (Tom Smithwick) The reason for the neither is...Stress programs that estimate the ferrule size generally draw a line across the rod at the cut point of the rod. Let's say a rod has is .218 at this point, calling for a 14 ferrule. If the female is 2 in. long, +- the insert offset, the rod may be .226 at the ferrule opening. You decide which ferrule would fit better. As far as defining a step downs, I have no clue. To do a step down properly requires an entirely different paradigm. You had a good question about mass vs. stiffness. Tom, believes that mass is the larger factor, as did Garrison. After looking at deflection for a couple of years now, I may be of the opinion that it is the stiffness that matters more. Tom, anyone, Have you ever taped a piece of soft lead the weight of an appropriate ferrule at the proper point on a one piece rod and cast it looking for differences. I know its not exactly the same, but... (Jerry Foster) I have one direct experience of the "what difference does a ferrule make" issue. I built a one piece 6’t Paul Young Smidgeon taper that cast quite nicely but did not sell so I decided to convert it to a two piece. Before doing so I taped a nickel silver ferrule to the rod and cast it. The slight extra weight could be felt but the rod still cast fine so I undertook the conversion. I used a truncated titanium ferrule so the actual weight that was introduced was minute. When the converted rod was cast it felt different again, the weight could not be felt but the stiffening effect made the rod feel stronger and I actually preferred it to the original. The taper is one that has a stiffer section through the center of the rod and I think this was emphasized by the ferrule. I think that weight is never a good thing as far as ferrules are concerned and that the effect of stiffness should be recognized in the design rather more than the available programs do at present. (Gary Marshall) Tom, anyone, Have you ever taped a piece of soft lead the weight of an appropriate ferrule at the proper point on a one piece rod and cast it looking for differences. No, but I have built the same taper from the same cane with and without the ferrule. Anyone who cast the rods could feel the difference. For me, and some others, it was not a contest, the one piece rod being superior in both feel and casting ability. However, there were some, including some good casters, who preferred the feel of the two piece rod. The original rod from which the taper was taken was a three piece rod which had a very slow action. The biggest jump in feel was between the three piece version and the two piece. The change from the two piece to the one piece was more subtle. I have experimented with taping more weight to an already existing ferrule. The results varied a bit, and led me to the conclusion I expressed earlier, that the weight matters more on some types of tapers than others, as does the stiffness. Ferrule weight does not show much on static deflection, but does show up in casting. Stiff spots are a factor, but the caster can compensate, although the feel of the rod may be compromised in some cases. Weight is weight, however, and degrades performance in most cases, and even if the designer carefully compensates for it, it's still there and can be felt by the caster. (Tom Smithwick) I think we all agree about 3 piecers. The problem is isolating the weight from the moe (tensile strength?) of the ferrule for testing. Once a rod has been made with a ferrule it is what it does. I wish I had a one piece available, I'd go test it right now. I think I'll give Chris a call, maybe I can club him into testing it for us. (Jerry Foster) Funny thing gravity. As G's increase, such as due to acceleration, things get heavier. One G during static deflection, 2 - 14 G's during acceleration and deceleration. Something that weighs 1 oz at rest will effectively weigh 5 oz at 5 G's acceleration. (Mark Wendt) The dummy that I am, I'm too stupid to make rods...I kept looking at your numbers and where you have a % sign, I was seeing degrees. That's the way I'm used to looking at it now. It's an interesting way of looking at a change. Again, a different way. neat. Both you and Al have alluded to some deceleration during some phase of the cast? If the rod ever decelerates during the cast the line will try to overtake the tip (like a mistimed haul). The least problem that would cause would be waves in the line, if not an entirely bungled cast. In a proper cast (of which I am incapable) the line is under constant acceleration from the beginning of the cast until the loop forms after the rod unfurled past vertical. This is way after the stop. But when we stop the rod begins it's spring action, so the rod is actually continuing to accelerate the line. So we do half the cast and the rod does half. (Jerry Foster) As others have replied and/or implied, the rod is accelerated at a changing rate and then decelerated at a changing rate and it all depends on whose casting it. A "pop and stop" approach tries to accomplish the acceleration and deceleration as quickly as possible but I believe in most bamboo casting situations it's not so abrupt, especially on the "stop" portion. A very abrupt stop leads to rod oscillation and line waves. I think most guys develop a technique which more slowly decelerates the rod, allowing it to give up its energy to the line in a smooth, wave-free fashion. I agree that the caster does some (most) of the work in accelerating the rod (loading it) and then the rod gives up its stored enery during the deceleration. There is a time during the deceleration phase (of the caster's arm) where the rod continues to supply energy to the line, therefore still accelerating the line. If the deceleration of the caster's arm is in sync with the unloading of the rod energy you get a bounce-free, wiggle-free cast. The proportion of line acceleration done by the caster versus the rod is dependent on the action of a rod. In a fast action, the caster inputs more energy that the rod. In a slow action, the proportion is closer to 50/50. The total energy is a balance of the two. I think you are the one who, earlier this year, asked how to determine the optimum rod design to maximize total energy. I think it is with a fast action but that doesn't necessarily result in a "comfortable" rod. (Al Baldauski) What am I reading? You mean this casting stuff is subjective? How unscientific! I'm starting to think it's like playing a musical instrument. Now I'm getting a suspicion that all you bamboo-rodmaking engineer mathematician physicists are not soulless robots after all. (Steve Weiss) Was that a compliment or an insult??:) I've always said, "It DEPENDS". That's why it hard to describe the perfect rod with a computer. And lord knows I'm not the best of mathematicians or engineers to be trying to do this, but I'm trying. I don't believe I'll ever get to rodmaking nirvana, but closer than I am today. (Al Baldauski) But how can we be sure its really not down to the effects of the ferrule distorting the action of the rod. And really has very little to do with the weight .I totally agree one piece rods do cast better.And also bamboo ferrule rods cast better providing the female ferrule is constructed as short as possible otherwise you just have a nasty flat spot. (Gary Nicholson) But how can we be sure its really not down to the effects of the ferrule distorting the action of the rod. No argument from me that stiffness is a factor, it's just that I think that weight is the bigger problem. If you recall my earlier post in this thread, I was suggesting that we take a further look at Marinaro's method as a way of compensating for both. As long as we are on the topic, let me relate the following: A couple years ago I spent a weekend on Spruce creek with a few other makers. On Sunday morning, I was fishing, alternating between the one piece and two piece twins to explore the differences. Chris Bogart came over to say goodbye, and as luck would have it, I stuck a pretty decent trout right at that moment. Anyone that knows Chris, knows that he ain't leaving while the fish are biting. What followed was a very interesting two hours comparing various soft hackle flys, and the characteristics of the rods being fished, both his and mine. I was roll casting to the far bank, trying to drop the fly between overhanging branches, and noticed that the one piece rod was more accurate. Chris said OK, lets do an oscillation test. So we got the rods bouncing up and down side by side. As I recall it, there was little difference in frequency and amplitude, but what we did notice was that the one piece rod bounced cleanly up and down in a unified motion, while the two piece version seemed to have harmonic vibrations along it's length. I doubt that we would have noticed them if we did not have the one piece rod for comparison. The next time I saw Chris, he had a hollow built, bamboo ferruled version of the taper, that I thought was another step up, both in feel and performance. I suppose you could go too far with this, and ultimately lose the "bamboo feel." I sure don't want to do that, but there's plenty of room for improvement in what we are doing. (Tom Smithwick) Yes Tom, I can see how that would work. Maybe we could run a test on this. One piece rod oscillation test first with weight fixed to mid section then without. (Gary Nicholson) Regarding the oscillation of the two piece rod, did you "synchronize" or line up both pieces spines ? I know some guys say they ignore any spine on the butt section but it seems to me that if you find a spine on the tip there's probably one on the butt too. It is a lot harder to find the spine on the butts I've made but not very hard on my tips, usually. It would seem to me that misaligned spines would affect the oscillation characteristics of the rod. Probably not in a good way. (Larry Swearingen) Your observations are correct if the rod is not synchronized when the rod deflected it will make the rod twist and jump sending vibrations down the section which is not correctly wrapped. (Gary Nicholson) I think both the weight, and the stiffness, of the ferrules do some amount of distortion in the action of the rod. Lets face it, the action really can't be determined until the rod has gone from some static position to a dynamic movement. That rod is being accelerated, and the weight of the ferrule has to increase due to the acceleration's imposing more G's on it. Take that weight (mass) away, and the rod has a different action. Take the weight of the ferrules, make a one piece rod of the same length, and tape a piece of lead onto the rod shaft at exactly the same position as the ferrule would have been, and I betcha you notice a difference in the action of the rod from not having that weight there. If the weight of the didn't account for something, why would we include them in the calculations of stress curves? (Not that a stress curve is the be all to end all, but that's a different discussion.) Every bit of hardware, thread, varnish or bit of whatever that is part of the rod's action length is going to do something to the stress curve. And acceleration forces, which make those components effectively weigh more, are going to affect the rod and it's action. I flew fighter aircraft for a number of years, and lemme tell ya, when you load that aircraft up with 6 - 8 G's during a hard turn, moving your hand, your head, or any other part of your body is considerably more difficult that it was in straight and level flight. The human head weighs, if I remember some of the schooling I got back in flight school, around 8 lbs. Multiply that times 6 G's, and your head now weighs 48 lbs. Little different load on your shoulders now, no? (Mark Wendt) Interesting.. There was a small gathering yesterday on the upper Rogue. This meeting is organized by Dave Roberts for the "State of Jefferson" fly fishing group. I was not able to attend but of significance was a test done by Bruce Howell. Chris O', Dave, Bruce, and a couple of others partook in the testing. A one piece rod was cast (8' #5) until they got the feel of the rod and then an appropriate amount of weight was added to simulate ferrules. Fuse wire of the proper ferrule weight was wound on the rod approximating the ferrule location and length of ferrule. The results were as follows: "Went to the gathering yesterday. Nice day and a good group of people. I had Dave try the one piece with the additional weight. (8- 5 wt.) Used fuse wire (8 grams) to represent a 14 ferrule and then again 10 grams for a 16 butt and 5.5 grams for an 11 tip of a 3 piece design. I could not tell the difference nor could I see the difference in the line performance. With the additional 1 oz of weight on the 3 piece I could "feel" the difference in the weight of the rod. Bruce " The interesting part to me is that there was no noticeable difference in line performance. While this is certainly not conclusive it has merit because the people involved were all outstanding casters. So if it is really not the weight, what is it that we feel on ferruled rods? It could be the stiffness or, as Bogart believes, it may be the interruption of the flow of energy through different materials. The guys are out fishing today but when they return home maybe they will chime in with their impressions. This does nothing to effect the Garrison paradigm, but it perhaps does show that ferrule weight is not the major factor in what we feel. Where is Baldauski when you need him :-). How could this kind of test be conducted in a more scientific format? I think Will just provided an answer. Oh, and Will.. that's .006 of bamboo, varnish has a different MOE. But I think a .006 layer of varnish really a lot of varnish. And that .006 / line wt. is just a heuristic, not a hard rule, as you know yourself. (Jerry Foster) You know me. I'm a firm believer in mass is mass is mass. And when it's effectively increased due to acceleration, it can't but help contribute (in ways both positive and negative) to the feel of the when it's in dynamic motion Vs in some static position. (Mark Wendt) I certainly agree with that, but maybe we have been overstating the influence of that small about of mass as compared to the matrix that it is embedded in. How much acceleration is really taking place at the ferrule stations? Also, I think G distributed the mass accumulation through the entire rod length. Perhaps if the ferrule weight were confined to its location on the rod the stresses would look different. Still, there seems to be a disconnect between what we (myself included) believe and the reality of what those guys did, or didn't feel. It may be that the ferrule mass has influence but is beneath our feel threshold. But I know ferrules influence the feel of a rod. I'm not trying to change anyone’s belief system here. (Jerry Foster) I think it kinda depends on the acceleration developed by the casting stroke, and how far away from the moment arm the ferrule is. The faster something is accelerated, the more G's are applied. And since the rod itself doesn't move on a straight line, the G's due to acceleration will not be identical at different points of the rod. The force that the G's put on the rod will eventually be distributed over the rod depending on how the taper is designed, but the instantaneous G is only felt at that moment arm. I think we're in agreement mostly. I too, think that a ferrule will influence the feel of the rod. It has to. The ferrule is made of heavier, denser and stronger material than bamboo. You stick something that's heavier, denser and stronger material between two sections of a beam, and you've altered the characteristics of the beam. That's just simple physics, and is dealt with in statics and strengths of materials sections. That's why we pay them durn injuneers so much to get this stuff right. Wouldn't want that bridge to collapse, now would we? (Mark Wendt) I think no matter how a ferrule is applied to the rod,or even which type is used it most produce a flat spot in the action of the blank. (Gary Nicholson) It DOES, but the effect is so small that it's not noticeable. The mass of a ferrule contributes to (detracts from) the action much more. (Al Baldauski) Yeah, but I think there's more too it than just that. (Mark Wendt) From my understanding you need to swell the butt of the tip to allow for the wall thickness. (Pete Van Schaack) The ferrule on a two piece rod typically contributes 7-8% of the total moment (torque) felt at your wrist. I suspect that is a difference you can feel. As for the stiffening effect: Sure, you've altered the beam with a ferrule but that stiffening is so localized that it doesn't make a noticeable difference in the feel. If you put a stronger link in chain, you haven't changed its maximum capacity. On the other hand, if you put in a weaker link, you will. (Al Baldauski) It may be localized in a static bend position, but as I posited in a previous email, perhaps we need to look a little more closely at the dynamic bend, and the effects of acceleration on the stresses to get a true picture of what's really happening with a rod taper during a cast. As to your analogy, I think we're delving into an apples/oranges thing there. A chain doesn't see the same types of loads that a deflected beam does, especially a dynamically deflected beam. It's seeing it's stress in a linear fashion, pretty much a straight line through the middle of the links. And in that case, the old adage proves true: It's only as strong as it's weakest link. But with rod action, we're not really looking at the total strength of the rod. We're looking at how dynamic forces are distributed down the action length of the rod shaft, and thinner or more supple sections distribute those forces differently than a thicker or more stiffer sections do. Add to that the effects of acceleration on the beam, and the resulting increase of effective mass in the heavier moments of that beam, and I'd suggest that to get a more truer reading of what a rod is actually doing during the cast, or for that matter, fighting the fish, we really do need to add dynamic forces to our calculations. A static bend in a rod is not a true representation of what that rod is going to do when it's in motion. (Mark Wendt) The chain analogy was not the best for visualization of the concept but it still holds. The affect of a ferrule's stiffness is localized whether static or dynamic. It's length and position on the rod determine how much it affects the overall rod. Statically (Garrison), the rod is assumed not to bend and the acceleration assumed is typically 4 G's. This imposes an incremental force along the length proportional to the mass of an incremental length. The bending moment, then, accumulates starting low at the tip and increasing toward the butt. The incremental moment of the tiptop is it's mass time acceleration time the distance from the grip. The incremental moment at the butt is, say, the mass of a one inch section times acceleration times the distance from the grip. This section may be more massive than a tip section but it is close to the grip so it's overall contribution to total moment isn't so great. Statically, all these moments add up to a total moment. This all assumes the rod is moved in a linear fashion during acceleration (and that's what we're taught is the "right" why to cast). Of course there is some degree of rotation but most of it occurs during the deceleration portion of the backcast and the forecast. Under this scenario, a change in acceleration changes the incremental force proportionally along the length and therefore the incremental moment as well. Since Garrison assumes NO deflection, the only thing you see from his curves is that the Stress increases or decreases as the acceleration goes up or down. In a Dynamic Situation: All of the above occurs but the rod BENDS. When it does the tip bends more than the butt and tries to point toward the load (the line and/or the fish) If the tip bends 90 degrees the force acting on it is parallel to the rod at that point and can no longer cause a bending moment. Therefore the force of the accelerated line (or the fish) is transferred down the rod to sections that are not bent so much. A dynamic deflection program takes all this into account by calculating the changes in moment along the rod length due to the changing angles of deflection at each increment and predicts a bent shape accordingly. This is what my program does and when you change acceleration, you can see the shape of the rod change. As the acceleration increases, the tip gets straighter "distributing" more of the force down the rod, and the mid and butt sections bend proportionally more. So the ferrule (its mass) acts to bend the rod more than if it didn't exist but its contribution is still proportional to acceleration in either scenario. The overall shape of the dynamic deflection curve changes due to its presence (mostly mass), the localized stiffness makes little difference. (Al Baldauski) The 4 G's that Garrison used is still a static figure though. As both you and I well know, a rod is not in constant acceleration. The initial moment of acceleration the rod could actually see much higher G forces, and then it slows down as the rod meets it's peak speed in the cast. It eventually goes to zero G's at the stop, then there are instantaneous G's applied to the rod as the rod bends past the point where the butt is held stationary, which then will go to zero as the rod tip finally stops. The butt has, for all intents and purposes, come to a resting force of zero G's, but the rod, as you get further down towards the tip is losing it's acceleration, though not at a steady rate. The things like the guides, the varnish, the wraps, and especially the ferrules (since they tend to have the most mass of any single component on the rod section for a given moment) will be affected by the dynamic G force increment, both on the way up as the rod is accelerating, and on the way down, as the rod is decelerating. All I'm saying, is that it's tough to apply a static amount of force for the casting stroke, and expect to come up with truly meaningful numbers as to what the rod is actually doing, especially during the casting stroke. It's a whole 'nother ball game when we try to determine what the rod taper is doing when we're fighting a fish. We've been looking at this problem for years and years based on Garrison's math (which is actually typical engineering statics and strengths of materials) which is nothing more than a snapshot of what the rod is doing at any given moment. I think to truly get a complete picture of the rods performance, we need more inputs to the math, and necessarily because of that, more outputs either in some kind of graph form or some other results tabulation that covers the entire casting stroke. Realizing that this increases the complexity at least a hundredfold of the data collection and the number crunching to come up with the results (which back in Garrison's day would have been a project of huge proportions since it was done longhand and with a slide rule) computers of today should be able to crunch those numbers a whole lot easier and quicker than back then. (Mark Wendt) The dummy that I am, I'm to stupid to make rods. I kept looking at your numbers and where you have a % sign, I was seeing degrees. That's the way I'm used to looking at it now. It's an interesting way of looking at a change. Again, a different way. neat. Both you and Mark have alluded to some deceleration during some phase of the cast? If the rod ever decelerates during the cast the line will try to overtake the tip (like a mistimed haul). The least problem that would cause would be waves in the line, if not an entirely bungled cast. In a proper cast (of which I am incapable) the line is under constant acceleration from the beginning of the cast until the loop forms after the rod unfurled past vertical. This is way after the stop. But when we stop the rod begins it's spring action, so the rod is actually continuing to accelerate the line. So we do half the cast and the rod does half. (Jerry Foster) In a proper cast (of which I am incapable) the line is under constant acceleration from the beginning of the cast until the loop forms after the rod unfurled past vertical. This is way after the stop. But when we stop the rod begins it's spring action, so the rod is actually continuing to accelerate the line. Don't buy this at all! No, No, No! Acceleration stops the instant you stop applying power at the grip. As soon as you start to stop the rod, forward acceleration stops. You can't stop the rod instantly. You have to decelerate the rod over time to a stop. The loaded rod adds nothing more to the cast at this point as it unloads. You have at this point all the line speed you are going to get. The line keeps moving as a result if inertia in the line and indeed overtakes the rod tip thus forming the loop. (Jerry Drake) Simple physics says that deceleration has to occur to go from a moving state to a stopped state. In this case, it's a rather rapid deceleration, compared to the acceleration which happens slightly less than the length of the casting stroke. The G's go to zero at the stop. Then the line weight causes G's to accumulate in the opposite vector because it's pulling the rod, rather than you, the caster, pushing the rod. (Mark Wendt) In order for a back cast to become a forward cast (or vice versa), all energy in one direction needs to be dissipated, and the line speed must decelerate to zero. But, during "false casting," the energy is not spent at the end of a cast because the line's weight and momentum remain considerable -- quickly loading the rod for a cast in the opposite direction. Only in the final, forward delivery is the loaded energy meant to be spent. As to acceleration or deceleration, there's the line itself to consider, but also the loading (and unloading) movement of the rod's tip. These affect one another, but do not behave in the same ways. At the beginning of a cast (in either direction), and when the line is fully extended and its motion stopped, the caster exerts pressure to move the rod in an opposite direction. From the rod's stopped position to its position of maximum tip-speed, there is only acceleration of line-speed and increased loading on the rod. Each caster manages that stroke differently, but the period of line acceleration does not stop at "slightly less than the length of the casting stroke." In fact, although the rod itself begins unloading its accumulated energy from (maybe) mid-stroke onward, and its tip-speed begins its deceleration, the line continues to accelerate until the rod reaches the end of its own movement, has spent all its energy, and the first inch of the line begins to form a loop. These final, mili-seconds of the line's motion before loop-formation might be described as an acceleration at a reducing rate of increase -- with actual deceleration from loop-formation onward. (Bill Harms) You're making my point, much more eloquently than I can. My whole point behind what I've been saying so far in this discussion, if we're to have a taper design piece of software that really does work correctly and figures out all the variables, we can't depend on static numbers to make it work. Garrison was the leg man in this whole thing, coming up with a good starting point to figuring out how the rod taper actually works, but it's well short of what we really need to correctly design a taper. Static numbers only work in a snapshot situation, and they're only good for that snapshot. 4 G's as a tip impact factor is only good for one singular moment in time - that time where the 4 G's are actually being "felt" by the rod. The rod is accelerating or decelerating throughout the entire casting stroke, and trying to make a static guesstimate is only good for that one moment in time. I think it was Frank Paul who wrote something not too awful long ago about he and his students doing some experimenting in gathering the mountainous amount of variables throughout the casting stroke. Maybe he can bring us up to date on what their experiment really covered. Frank? (Mark Wendt) Yes, there's no difference between your point and mine. I only wanted to explain that the line and the rod accelerate and decelerate somewhat differently, and that load on the rod is in constant flux -- exerted, first, at the butt by the motion of the casting hand, and then, in consequence, by the line itself. But you're surely right in suggesting that a static test of any sort will fall short of describing what the rod actually experiences. Static tests can show what the entire rod may be experiencing under some given circumstances, and within a given "flash" of light. But a fly rod loads and unloads (as well as accelerates and decelerates) sequentially along its length, and no single moment in time can describe the play of these dynamics. (Bill Harms) You did wake me up this afternoon Mark since you raised an issue that I fooled with sometime ago at the university before retirement. I don't have all my stuff here at the PA cottage to look at the detail, but let me suggest that the problem of dynamics is more complex than static rod behavior. I think you both have captured the issue with acceleration and deceleration of the casting process. As I think I have pointed out in the past, our research experience clearly showed to me that the rod, line, and caster are a system, and if one wants to come up with the ideal rod based on a systems approach, the problem is quite complex and requires a lot of detailed work - if it can be done at all. I do have quite a bit of experimental data back in South Carolina from data taken on a carbon rod - measurements of velocities and accelerations ( I don't recall the specific details) of a caster with rod and line. We also did some measurements for just a rod in terms of modal frequencies that showed the first two modes are the most important in rod design from a dynamics viewpoint. One thing we noted in our work was that while a rod can be designed to have a fundamental modal frequency, that modal frequency becomes smaller when a line (could be the line length or the line weight change) is added to it. This fundamental modal frequency also changes again when a caster is added to the rod and line combination, again reducing the apparent fundamental rod modal frequency. So, the long and short of the problem in my opinion is that there is no ideal way to design the "perfect rod". Just as the taper design influences the rod behavior, the addition of a line and caster further changes the equation. I am sure that is why different ferrule types also influence how a bamboo rod behaves. I guess that is why one fisher person likes one rod and not another and vice versa. (Frank Paul) Yousens can parse this any way you want to make your own point. For the purpose of clarification I will reclarify and rephrase mine, one more time. AT THE POINT YOU WANT TO DESCRIBE AS DECELERATION, WHERE IS THE ROD TIP. Does the rod continue to accelerate the line? I understand that if you are decelerating the rod it is no longer accelerating. I also somehow grasp the concept of slow stop, soft stop, hard stop, pop stop, and pop tart. (Jerry Foster) Go outside and begin softly flicking the line back and forth. Don't try for any distance, just enough to let you easily keep the line in the air without working at it - 20' or so should do. Cast with one hand, trap the line with a finger and leave your second hand free. Once you have an easy rhythm established, bring up your off arm and hold it in front of and perpendicular to your casting arm. Let the second arm act as a stop, bringing your casting arm to a sudden, abrupt and complete stop. Observe the line... Now, I realize that most of us cannot stop a rod this abruptly, but you are going to have to work hard to convince me that the stop introduces waves in the cast, or that the rod is not accelerating the line. (Larry Blan) I wish to amend my clarification, but I don't think I will. Just practicing to enter the primary. Ooops I guess I'm a day too late. (Jerry Foster) Have you been watching Lefty Krehs' video again? I've seen him do this many times during his casting demos and the loop that forms when he did that was so small and tight that the cast probably would've kept on track going into a gale force headwind. But then again, not many people can handle a fly rod like Lefty. (Will Price) It depends. Let’s assume a forward cast. Deceleration (of your arm and hence rod) begins the instant your hand is NO LONGER APPLYING FORCE in the forward direction. Also at that instant, your hand is still gripping the rod and opposing the moment created by the loaded rod allowing it to continue to accelerate the line. When the rod is unloaded, wind resistance on the rod and line as well as your grip begin to act to slow the forward motion of the rod. All of these things happen in a complex way DEPENDING on the particular taper and caster. Where is the rod tip, you ask. I’m guessing it is nearly straight and slightly forward of the caster. (Al Baldauski) At the point where the rod decelerates to zero G's, the rod tip may still be following the rod, due to the friction and mass of the line in the air, as well as the way the taper moves energy up and down the rod shaft. At a singular point in time though, that rod tip will reach the point of zero G until it transitions to a slight forward acceleration, because of the line pulling the tip forward. Due to the taper, and the design of said taper, different parts of the rod will be decelerating at different velocities. (Mark Wendt) How about taking one taper and have everyone give their version of what it should look like. All the talk just confuses folks, and me. I'm willing to give one of my tapers and you can chop it up and show what all these differences amount to. It's a 2 piece 7'6" rod, I use 50 ft of line outside the TT You need to calculate line size and action 1 69 I'd say it is a progressive #4. (Hal Manas) It's a 4 wt tip on a 5 wt butt. The concave tip would probably be too soft for a 5 wt and a 4 wt probably isn't going to maximize the power of the butt. Said another way, this would be a heavy 4 wt. Not the best strength to weight ratio. I'm not sure how to describe the action in commonly understood terms. That's what the deflection charts are for as Al has described them. Download FlexRod from my blog, load the taper and compare it to a few tapers that you're familiar with on the water. Use the summary sheet to compare the straight and bent stress curves to the bent rod chart. Also, the detail sheet clearly illustrates the concave tip. Like they say, a picture is worth a thousand words. (David Bolin) Without graphing it it looks like a fastish straight taper, its Gould rating of about 300 gives that and most increments are therefore about 15 thousandths. You could make the tip a fair bit finer with advantage (Didn't you just know I'd say that!) and if you're really going to push out 50' of line or the fish are big then increasing the rate of taper in the butt 30'' wouldn't do any harm. It will feel like a crispish actioned, fairly powerful and surprisingly rather short rod, I've got one a bit like it. Should handle a #6. There you are, all on first impressions without calculator, graphs, stress calculations, anything. So you can all now thoroughly enjoy telling me I'm right up the wall! (Robin Haywood) This looks to me like a strong progressive 4 wt. I like the look of the taper but think the tip looks a bit thin at the 10" and 15" stations. It might feel a bit too weak for the rod with more line out - especially with the strong butt. I would change the tip figures to something like the following. This would have a very similar feel but I think would offer slightly finer control for the very short casts and smoother loops for longer lines. 1 55 OK, I'll play Interpretation of stress, or raw numbers, is a personal thing. Each of has to decide where in the stress range we like our rods. In the case of makers we also get to decide for someone else. To me, this is a solid 4 wt maybe even a little better at 40' but fast (stiff). (Jerry Foster) Really, what I should have asked was what does this taper look like IN YOUR PROGRAM. You know plug in the numbers and see exactly what it looks like to you. Specifics not just generalities. What would be interesting to me is how your particular program sees it and how it could or should be modified. A lot of folks have talked about their program and how it calculates rod tapers, It would be nice to have the same taper looked at by all. If you don't like this taper just choose another that we can all look at, I have no problem with that. I would suggest that we all use 50 feet of line and at least for this, use weights 3 times the AFTMA values for the 90 foot line. So is it a 3 wt or a 5 wt or what ? I'm just interested in how others view tapers. I have a rod that is similar to this and was thinking of modifying the tip to this taper. I will give my impression of it after others have commented. There are no tricks or hidden factors, It just a plane simple taper. (Bob Norwood) Changed, or modified for what? It's your rod do what you want with it. I disagree with you holding to 50' no matter what, I use the distance-to-cast to design the rod tuned to the distance I foresee it being fished at. And 3 times the AFTMA value for the fist 30 ft. doesn't mean anything. (Jerry Foster) You probably didn't mean it that way but I'd be very skeptical about programs that actually generate tapers, but they can certainly be useful for analyzing them. I'm afraid I've gone back to good old graph paper for origination, and Hexrod for quick comparisons, its a speed thing mainly, but Hexrod would be much improved if we could have a "Modify tapers" facility like the "modify stress curve" one but smoother and quicker. Since Frank isn't paid for maintaining Hexrod I'm not even going to consider asking him to do it. He may get round to it for personal amusement one day, perhaps. (Robin Haywood) In my book it is a fast actioned 4 weight that may handle a 5 if required. Looks close to a straight line taper with a nice steepening 20" to 10" to give a softer tip but then backs off over the last 10" for safety. No compromise given to roll casting but will generate good line speed in a conventional cast and likely to be able to form tight loops without difficulty. (Gary Marshall) I'm still in the process of developing a technique for evaluating a deflection curve in order to be able to define an action and a line weight. That's why I said yesterday I have arbitrarily assigned a % deflection to try to be able to evaluated one rod against another. My thinking is that overall deflection is a measure of the energy a rod holds, therefore line weight and line out. The shape of the curve defines the action. So, with the numbers you proffered this is what I think: The rod is a medium action because it bends rather uniformly throughout its length. I would say the taper as designed could be considered a 5 to 7 wt, depending on who is casting it and how much line is out. I would say that it is a 5 wt designed to handle about 45 to 50 feet of line If you wanted it to perform better in a closer fishing situation, you'd either have to go with a greater line weight or change the tip dimensions. I would change the tip dimension as follows: 0 0.055 This would allow you to fish closer without compromising your distance using 5 wt line. (Al Baldauski) Interesting take on this. I guess this really highlights the need to know what the rod will be used for. It also begs the question as to when changes made to a taper results in the creation of a totally different animal. I like Bob's taper for the most part and my approach was therefore to tweak it a bit. Your approach in some senses represents a greater departure from the original. I think you are totally correct in saying that your tip would probably fish better in close (than Bobs' or mine). It appears that the tip will deflect just over an inch more with 15’ of line out) I think all 3 rods would be reasonably similar at 45-50’, I think yours would not comfortably handle a longer line than 55’ whereas Bobs' and mine would. For an all round rod I would personally compromise that little bit on the close-up aspect in order to accommodate the ability to also cast a longer line. If the rod is only going to be used for fishing short I would probably also thin the tip but would then also consider removing some unnecessary material from the rest of the rod as well. (Stephen Dugmore) Someone else said it this morning, "I design my rods for the distance fished and line weight". I couldn't agree more. The two can't be separated. Then you have to consider the individual caster. Does he like a laid back style or an aggressive, graphite style, or something in between? Now put it all together as best you can. If I compare your rod mod against mine, the total tip deflection with 15 feet of line out is virtually identical but the shape of deflection is different. My tip is more flexible and makes it look more like a faster action, hence more tip flexing, but since I've removed more mass with a thinner tip there is less bending moment transferred into the butt so the total deflection stays about the same. (Al Baldauski) Okay, for those of you that use static stress values to develop and evaluate tapers, what values do you consider to be within acceptable range to turn the amount of line cast? What is too little to get the rod to flex and what is too much? (Ralph Tuttle) That's a hard question to answer. From what I've studied, it depends on the action of the rod you have. A fast action rod will have high stresses in the tip section (200k - 250k), drop rapidly toward the mid and stay relatively constant toward the butt. A slow action rod will have a nearly level stress curve (sometimes lower at the tip than the butt) with values in the 120k to 140k range. Then there's everything in between. (Al Baldauski) It's that range of functional designs that I was researching last year. I finished the research up with a set of five tapers that represent the general design characteristics of 444 hex tapers from RodDNA. That research is documented on the blog in the Tapers category. Scroll down to Taper Research #1 and read the four posts in sequential order if you're interested. Download FlexRod from the blog and you can play around with the five standard tapers. FlexRod includes deflection analytics similar to Al's. (David Bolin) For what it worth I am with you I think there is a difference in action in feel and vibration. How many rod makers have cast a spliced rod? If you take salmon rod 15’ with two ferrules compared to a 15’ spliced salmon rod. I think you will find a difference. But its only my opinion. (Gary Nicholson) Where is Baldauski when you need him :-). How could this kind of test be conducted in a more scientific format? Thanks for thinking of me, I think. I’ve just come back from a week of fishing so I’m trying to get back into the LIST. When it comes to “feel”, I don’t know if there is a better way to test these ideas. If it were a blind test it may be less subjective. My deflection program comes as close to being objective as I can think of. I can change line weight, number and type of ferrules, line out, acceleration, and dimensions to see the effects in deflection. Here are some results on a Garrison 212E.
These data suggest: About ½ line wt difference for one ferrule + or – Adding 0.006” along the whole length (it actually should be somewhat proportional to diameter) equals about one line weight As far as the “feel” changing due to increased stiffness cause by ferrule, I’m not convinced. I did some calculations on the added stiffness due to the presence of a ferrule and it is about 10% but only for the approx 2.25 inches of a truncated set. In order to see a deflection change based on a change over a 5 inch length of rod equal to a one line weight change you have to a subtract 0.050 inches at the mid-section (0.214 diameter), creating a huge hinge. If you add 0.050 inches, the added stiffness (more than double) changes the total deflection almost a negligible amount although the shape of the deflection curve is changed, albeit little. The effects of the above changes are less on a stout rod and more on a softer rod. The weight of the varnish can be ignored. On the 212E it amounts to 0.22 oz , most of which is distributed over the butt end where it has least effect on bending. Its stiffness is less than 1/10 that of bamboo, so that’s irrelavent, too. Some fact and some opinion. (Al Baldauski) When you are talking about tip deflection are you talking about the tip angle, or the entire rod (butt to tip) angle? Seems strange that adding .006 to a rod and keeping all other variables constant, the rod would deflect more? Makes me think all of my assumptions are in error, error, error. More bamboo, and more ferrules, make the rod softer? I'm sure I'm missing something here. (Jerry Foster) So sorry, I use the list to proof read my data!:). I meant to type " with 0.006" REMOVED along the length". That probably makes more sense to you. Me too! (Al Baldauski) Sorry again, I didn't answer all your questions. In my deflection program I have arbitrarily assigned a percentage of deflection by plotting the deflection curve and determining the coordinates of the tip. I have oriented the graph so the rod is vertical when not bent. As you bend (deflect) the rod it effectively gets shorter on the Y axis as it bends away from it in the X direction. I divide the X coordinate by the Y coordinate and multiply by 100 to get percentage of deflection. This percentage gives me an idea of how "strong" the rod is (what line weight it needs) and the shape of the curve give me an idea of how, where, the rod bends (fast, medium, slow action). I'm still in the process of trying to accurately relate deflection data to actual rod performance. (Al Baldauski) Maybe this is something to think about as a possible addition to a taper analyzation program - the effects of acceleration on the deflection (stress?) curve. I know it's adding a dynamic to the mix, where we're actually working static stresses and such, but in this conversation we've been having about ferrules and varnish and guides and such, the increasing/decreasing effects of acceleration (read G's) on the moments has got to have some kind of impact on what constitutes the "feel" of the rod while casting it. We've looked at taper design for oh so many years from a static bending moment, without really taking into account the dynamic bending moments. I just wonder if that's something that can be added to a software program that would give us even greater insight into how a given taper design is really working. (Mark Wendt) In fact my program can take into account different accelerations. As you would expect, more G's constitutes a greater moment and consequently greater deflection That's why one rod "feels" good to some but not others. One caster uses greater acceleration than another. Give a graphite guy a bamboo 5 wt rod with a 3 wt line on it and he'll think it's great. The bamboo guy will think it's a crowbar. (Al Baldauski)
Is the weight of the ferrule enough to go on and on about and I never hear what that has to do with casting the rod. The only impact the weight of the ferrule can have is after the stop point in the cast. Maybe some slight localized increase in momentum. Immeasurable. The point about the stiffness is that during the bending and unbending part of the cast any material that is not bamboo will deflect differently (than Bamboo). I was not making the case of an unyielding ferrule. Merely that it will have a different MOE, MOI, than bamboo. So tell me how the weight of any normal ferrule impacts the deflection of the rod. (Jerry Foster) I think both factors of ferrule weight and stiffness affect the performance of the rod. Significantly? Depends... Extra parasitic mass would rob energy that could be used to airialize (not sure if this is even a word) and propel the line...or maybe tune the rod vibration to a better/worse behavior. Localized stiff spots in the elastic curve would interrupt the stored strain energy. Detrimental or features? The deflection caused by the extra weight of the ferrule is offset by the decreased deflection caused by the stiffness of the short length of the ferrule and in the end it is most likely a wash. All this worrying about rod joints is a discussion for those that enjoy the wringing of hands and the gnashing of teeth. Get rid of the ferrules and go with a one-piece rod. If you want to thoroughly screw up a rods action go with a scarf/splice joint. Gnaw on that for awhile. Thats my story and I'm stickin to it. (Jerry Drake) Why does a splice joint screw up the action? I have made several and find them to be most similar to the several one piece that I have built. (Bill Lamberson) The action is screwed up because at every splice/scarf the stiffness is asymmetrical. This changes the bending characteristics of the rod shaft under load. You do not have this change with ferrules. (Jerry Drake) This is brief but I am sure you will have no trouble with it. Having followed your posts for a number of years, I suspect you are already aware of the following. The splice/scarf joint facts:
The flexural rigidity of the joint is the sum of the flexural rigidity of each half of the joint. Flexural rigidity is the product of the Modulus of Elasticity multiplied by the Second Moment of Area of the beam or E * I Since E is the same for both halves of the joint one needs only to consider I. The Second Moment of Area about the x axis decreases by approximately 74% at the center of the splice. The Second Moment of Area about the y axis remains the same through the length of the splice. Because of the difference in the Second Moment of Area about the x and y axis any force applied that does not pass through the sheer center of the equivalent section will cause rotation. The experiment A three-piece splice joint rod was mounted and the deflection under load was measured. The flats were numbered 1 thru 6 with number 1 being the flat with the guides. There was a strong tendency to rotate when the rod was turned to any flat except flats 1 and 4. The splices were then glued together with resorcinol glue and the above deflection measurements were repeated. The rod with the glued splices did not exhibit tendencies to rotate when loaded and the deflection was reduced. The glued rod required an approximately 15% heavier line to properly load the rod during casting. My challenge to anyone is to repeat my experiment and post their results. I will be happy to supply detailed instructions of how to proceed. (Jerry Drake) I was assuming that you were assuming that a taped splice did not move enough to matter, although a small amount of fretting would, I suppose occur. Its called micro-fretting and occurs on any joint relying on friction and causes minor local fatigue on metal to metal joints. Your experiments seem to prove that it causes more movement than I thought. I don't like spliced joints, mainly because they look so awful,but,many years ago someone gave me a greenheart salmon rod to look at because he could never get the butt to middle splice to stay tight during a days fishing.In this case the splice was too short,less than the six times its diameter that is normally considered to be a minimum.I put a couple of brass sleeves at each end of the splice which seemed to cure it,although for how long I don't know,but he was happy with the result.Fortunately greenheart is a very dense wood,so compressibility was hopefully delayed until the day his increasing age meant that he was unable to wield this 18' greenheart telegraph pole any longer! Properly fitted ferrules really shouldn't twist, either, although the old brass ones used in ancient times were very prone to wear and deformation under stress.Many thanks for your excellent work and most informative and instructive post, I have apparently been right for the wrong reasons, and I welcome your correction. (Robin Haywood) Draw a diagram of a splice joint during bending and then add the force vectors resulting from the bending moment. You will notice that the tension force on the outside of the bent joint tends to separate the faces of the splice reducing friction between the faces. It is a pretty tall order to come up with a tape that can apply enough pressure to create enough friction to resist those forces. I use metal ferrules on my spey rods up to size 32. One of these rods is 15' long casting an 800 grain long belly line. I have not had any trouble with any of these big ferrules. (Jerry Drake) I did some calculations this morning. One ferrule in the middle of an 8-foot rod has the following effects:
The net deflection difference is 0.3 inches out of a total deflection of 31 inches at the tip. The ferrule produces a flat spot in the rod (a reverse hinge). Does this make a noticeable difference in feel? Can anyone feel a difference of 1% in total deflection? I don’t know! Keep debating :>) (Al Baldauski) Pretty much what I expected. I am guessing you used the weight of a NS ferrule? (Jerry Drake) To what exactly do you attribute the increase in weight causing the rod to slow down. Is this based on A Garrison model? I know it's your own deflection code. The whole thing seems to be a little counter intuitive. The stiffness part is easy to see. but if i add more mass (cross sectional area) to a rod it stiffens the rod and speeds it up... True? The whole feely thing is very individual. Attempts to compensate for the ferrule (Dickerson, Marinaro, Payne) result in different deflections, (when compared to a non-compensated rod). This simply results in a slightly different rod action (deflection). Is this good yes/no, it results in more diversity, which is good. Is it a better rod, no. It is just a different rod...good... the druthers of likes and dislikes are up the each of us who cast that rod. I'm glad too see someone else relating rod speed to total tip deflection. After-all the more a rod bends the longer it takes to straighten. Slower. I believe most of us internally relate rod speed to the time it takes the rod to deflect to the stop point. Where in fact the rods action also should include the time it takes to straighten. I haven't really seen anyone model the rebound (straightening part of the cast, SPRING) after the stop. Max made an attempt but I believe he made one assumption I don't agree with. He used the total rod deflection as the value of the overthrow portion of the cast. Where in a perfect world the force applied would be totally transmitted to the line and there would be little energy left to cause this much overthrow. One of the things that confuses the issue is using old marketing terms to describe a rods action. Typically, people refer to a "Dry fly action" as a "fast tip", where in truth those rods have a fast butt and a slow tip. (Jerry Foster) Thanks for the data Al. Seems that it would take a very precise casting stroke to notice a 1% difference in rod deflection..... Would it be easy to re-run your analytical model moving the hypothetical ferrule up from the mid point by 15 inches? Reduce the weight and length appropriately for a top ferrule of a 3 piece? Wouldn't it reason that the mass fractional effect would increase as you move the ferrule toward the tip and decrease as you move it toward the butt? So it seems that the only significant benefit of different ferrules (regular, truncated, maybe micro) would be appearances, overall weight (this is being generous), and the increased difficulty in fitting the smaller sizes? (Gary Young) I cannot easily model incremental moves of a single ferrule in a multi-piece rod. My rod program is designed to adjust for different ferrules, standard and truncated, but uniformly positions them based on the number of pieces selected. I can get deflection curves based on a chosen taper holding all aspects constant except the number of ferrules. This would show total tip deflection of the rod with differing numbers of ferrules. I can then run a conversion of the given taper which produces a NEW taper compensating for the presence of the ferrules chosen. The program calculates new dimensions so that the new taper has the same total deflection as the original. This results in a new rod that bends the same when using the same line weight and the same hypothetical casting stroke (a fixed acceleration which implies a maximum deflection). The resulting rod will FEEL different because of the different weights and placement of ferrules as well as the increased mass of bamboo necessary to keep the deflection fixed. My assumption is that the same deflection will result in the same performance with the chosen line weight. Using lighter ferrules at any given location should keep the FEEL closer to the original. (Al Baldauski)
Is there a general rule of thumb for how one adjusts the specs of a taper taken from an older rod with stepped down ferrules so that the rod being made properly accommodates a Super Z ferrule? Thanks in advance for your replies. (Doug Hojem) Just average the numbers. No one will ever pick it. (Peter McKean) I'd average the drop at the ferrule to thin the butt/beef the tip. But why don'tcha just use the step-down? (Steve Yasgur)
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