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What's the best procedure for changing the line weight of a taper using Hexrod? What I did was input the original line weight and dimensions of a rod (say a 6' #4) to get the stresses. Then I changed the line weight (to #2) and started tweaking the dimensions until the stresses were roughly the same as the original rod. Could I reasonably expect the new taper to have a similar action got with the lighter line? (Bill Benham) Use the Online Interface to Hexrod that is under the Software section of the Rodmakers home page, it will do all that for you, just input the changes you want to make and, presto, new taper. It also has a great taper archives and lots of other features, not to mention a search engine to search the List archives. (John Channer) If you enter the original as you said and then hit the button that says something like "change rod fundamentals," change the line weight and make sure it says "keep stress curve same" at the bottom, it will recalculate the dimensions and the stresses should be identical to the original. When it says that the stresses are identical, if you go down in line or longer in length - expect the action to be slower than the original. At least, that's what I have observed. (Jerry Madigan)
I am intrigued with using Hexrod to determine line weight as you describe. However, when I check certain rods, like Gary Lohkamp's Dickerson 8014 posted to the online archives, I have to bump the line weight up to 9 or 10 to get that upper range at or near 200,000. When do you know when to stop? Like in the above 8014 example, the 6 wt stresses are this: Point Dimension Stress 0 0.076 - As a 9 weight the stresses are this: Point Dimension Stress 0 0.076 - Are there some rods it works better on? Am I completely misreading what you are posting? Hexrod is a useful tool in many ways, but I am stuck on this one and would like your expertise. (Bob Maulucci) Amount of line fished is an important part of the calculations. You can keep the same line weight and increase the amount of line fished to increase the stress values. The stress curve for a 4 weight at 55’ is about the same as a 5 weight at 45’ with the same dimensions. (David Dziadosz) The other factor to take into account is the length of the line that you feel is a normal cast. I generally put in 40 feet, but if you know you are going to be casting 65 feet most of the time, then there is a lot more weight involved. Also take into account the weight forward lines go into a thin running line at about 40 feet, so the weight increase will not be that much past 40 feet for WF lines. DT lines will have an increase in weight all the way to the backing. Some rods are just stiff, and the were designed that way. The Lee Wulff 6 footer - I forget what it was called - is another one that has a very low stress curve. Didn't he make it to catch salmon? (Darryl Hayashida) I am assuming the online Hexrod is using DT as the default line type since I get no choice, but I guess it doesn't matter because in testing it is not changeable.... So I earlier determined that the Lohkamp taper of the Dickerson 8014 is more of a 9/10 weight than a 6 weight at 40' using the default line type, but it is a good 6 weight when using 70' of line because then my high point maxes out at around 200,000? (Bob Maulucci) It's a matter of your preference. If you like the way it casts at 70' with a 6 wt. and the stress curve is saying the peak is at 200,000, then for future reference use that value. I've found that for dry fly fishing a maximum point closer to 250,000 is better for me. If I make a nymphing tip for a rod I make it with a more rounded peak on the stress curve and closer to 220,000 (usually a little below). A stress curve by itself is meaningless. You have to relate it to the way the rod casts for you, and what you like. Graph up all the rods you can, go out and actually cast the rods, look at the stress curve. Soon you will be able to relate the stress curve to the way the rod casts. You will find that similar rod actions have similar stress curves. Then you will be able to design a rod by using just a stress curve. (Darryl Hayashida) Okay, let me ask this again. You don't need to explain any other facet of Hexrod to me, just explain the way you use it for to determine line weight to me. This is my understanding of your method... You have said on the List that when Hexrod finds the stress curve for a given taper that ranges within the 120,000 to 200,000 range that is the approximate line weight for that rod. For example, when a lister asks what line weight the rod should cast, you have answered that they can run it through Hexrod and see a stress curve that peaks out near 200,000 and that means that would be a good starting point. I just want to know if that is what you are saying to do? Yes or No? (Bob Maulucci) Yes. (Darryl Hayashida) If you are using the Garrison stress curves to compare rods then I think you must fix the length of line or the comparisons will not have a common basis, i.e. if you want to compare the shape of the stress curve for a 7' 2/2 4 wt to that of a 8'-6" 3/2 6 wt then you must keep the length of line the same... JMO. (Kyle Druey) The overall shape of the stress curve doesn't change much with different line lengths, or even different line weights. You will have proportionally higher peaks with greater weight, and of course the stress values are higher, but the over look or general shape of the stress curve doesn't change much. (Darryl Hayashida) The shape and location of the curve are relevant... i.e. I can have a straight lined stress "curve" at 200,000 and it feels like a real noodle or have the same straight line at 100,000 and it is much stiffer... so I think shape and stress levels are important for comparisons. (Kyle Druey) Okay. What I am saying is in trying to determine the line weight of a rod that you do not know the line weight, plug in a line weight in Hexrod and look at the stress curve. Use a line weight with the length of line that you feel is reasonable. With a weight forward line I use 40 feet. Most WF lines turn into a thin running line around 40 feet and will not add a lot of weight past 40 feet. adjust the line weight until the top of the curve reaches around 200,000. Go out and cast the rod using that line weight and your length (whatever it is - 40 feet for a WF) as a starting point. Determine if you like the way the rod casts. If not, use a heavier or lighter line. Find the weight of line that feels best to you. Go back and plug that line weight into Hexrod. Note where the curve is - lowest point, and highest point. Use those values in the future to estimate a line weight for a rod that you are trying to find the line weight for. (Darryl Hayashida) It is my understanding that the stress curve can do about 3 things for you. 1. Give you a "fingerprint" of the taper which gives you a clue to what Wayne calls the rod's character. 2. Allows you to estimate the position and magnitude of the maximum bending stress. 3. Allows you to duplicate the stress curve (general character of a rod) using different fundamentals (action length, line weight). None of these is exact. Function 1 requires that you know what casting characteristics correspond to which stress curves. This requires that you cast rods with various stress curves and remember how they cast. Function 3 allows you to re calculate the stresses using different lengths and line weights (what you see is not always what you get, particularly when you make radical changes in rod fundamentals). Function 2 (the one being discussed here) is estimation of maximum bending stress which Garrison only used to determine the load limit for a rod- Not the appropriate line weight and length cast. Bottom line: The rod does not cast best with the maximum stress in a particular range of magnitudes. The rod casts best with the line weight you determine as best by casting it. (Doug Easton) I agree with what you are saying. I just posted a message, and I have said it before, that a stress curve is meaningless unless you relate it to the way a rod casts for you. By "you" I mean you personally. Not the way it casts for me, not the way it casts for your buddy, the way it casts for YOU. Cast a rod yourself, look at the stress curve. After you have done this many times for many different rods you can start designing rods by using a stress curve by itself. As a function of a lot of experience with a stress curve you can get a real close approximation on the line size. Not exact, but close - personal preference again. (Darryl Hayashida) Regarding your question. I would be very careful trying to determine the line size just using Hex Rod. You do not know what the maker had in mind when he was making the rod. As for the 200 thousands point, I have made many fast rods that, using the right line size and line length, peak at over 250 and they are fine rods. From what I can see, the 8014 is a very stiff rod having an average taper difference of 15.3 thousands between stations, (13.4 is a good average for most rods.) It is very stiff from 5 to 30 inches, then will flex some to 50 inches although the ferrule will stiffen it up at 48 inches. The butt is also very stiff except for one point at 70 inches where it will flex a little. Over all it is a stiff rod that will handle a 6 to a 8 or maybe 9 wt line. It is not one I would like. Have you tried it or built it, would be interested in your comments. (Bob Norwood)
If I want to modify a taper to make a 4 wt a 5 wt, should I simply bump each station up .006 or should I tweak the rod until the stress curve for the 5 wt is exactly the same as the stress curve for the 4 wt? It seems to me that I'd want the stress curves to be the same but I've been told it's the other way around, simply bump it up by .006. I've done both and the design with the identical stress curve gets up to .014 larger than the original rod in the butt and .011 in the tip. Presumably this would make it a 6 wt? (Jim Lowe) If you use Hexrod to change the line weight, it increases the diameter to keep the stress curve the same, in other words, it increases by a proportion, rather than a fixed dimension. If you just add .006 to all dimensions, you have made the tip drastically larger and hardly changed the butt diameter at all. I believe in the Hexrod method, even though stress curves leave me cold and I never look at them, I look at the actual taper graphs. (John Channer) Good point John, thanks. I think I'll go with the stress curve approach. (Jim Lowe) Surprisingly, Mr. Milward suggested adding a fixed amount to each taper to increase or decrease it by a line size. To be fair he only suggested it for one line size, but such technical sloppiness is worrying in a architect! As you say,you should modify rods by using the "Stretch stress curve" option, not the other one, which I don't understand. I do understand stress curves, and do go along with Milward's suggestion that they might be misleading. However, since they are not especially useful for taper designing, proving as they do that all tips are too thick but not much else, we may safely consign them to history. What IS useful, as a once only exercise, is to equalize all the stresses using the Hexrod "modify stresses" option, and see what shape you get........ I might add that we suffer the same problem with hollow building, the wall thickness should be a constant proportion of the overall diameter. (Robin Haywood) I think Ray Gould in his first book also suggested adding a constant to change line size? (Steve Dugmore)
If I take the numbers for a 4 wt rod and feed them through Hexrod and change them to a 5 wt, is there any tweaking I need to do to get the action as close as possible? Both would be the same length and its not a complex taper. (Bill Walters) I think that Hexrod gives a much better conversion than the old "change by .006" every station". I've made about 2 dozen rods with the original tapers changed by using Hexrod and I have liked the results every time. (John Channer)
I want to convert a taper from a 4 weight to a 5. I did this with Hexrod by increasing the line size to a 5 and holding the stresses constant. What's the rule of thumb regarding the length of line cast in Hexrod? Should I increase it from the 40 ft. for the 4 weight to 45 or 50 for the 5? Do I have to leave it the same as the 4 weight version for the 5 weight rod to have the same feel? How about if I wanted to take it from a 4 to a 6? I think I've read that, in Hexrod, as the line weight goes up the line cast should too, but I couldn't find anything in the archives that says by how much. (Bill Benham) The line size of a rod is all about weight of the line in the cast, so it's the length of your average cast with a DT line or level line if you use a level line. But consider this - if you use a WF line once you get into the running line very little weight is added no matter how long the cast. Most people shoot the line once they get past the belly anyway. So, the basic questions are: What type of line are you going to use, and what is the average length of your cast? I have a short rod that where I usually use it I don't cast more than 15 feet. The average cast is under ten feet. To load the rod in that short a distance I use a 5 weight line. If I think I'm going to cast more than 20 feet I use a 4 weight line. I sometimes use a 3 wt DT on it, but I usually don't go lighter than a 4 wt if I use a WF line. (Darryl Hayashida)
Got a friend who really likes a rod taper and wishes the 5 wt. 7' 2-piece action to be translated to a 3 wt. 6'6" 3 pc. Any ideas how this could be done. I've plotted out several tapers and am still not convinced I got it right. (Don Anderson) I must be getting old and difficult to get on with, but I just fail to see how someone who REALLY likes a rod can conceivably want EVERY parameter changed. I would tell my friend to find a rod with the 3-piece etc specs that he likes, and then I'd build him one of those. Easy-peasy! (Peter McKean) This guy has a large collection and the rod he likes is a 2 pc. 5 wt. He travels all over the place and wants a shorter luggage friendly rod. So, I'll try to build it. Such is life. (Don Anderson) Hmmm. I gotta agree with Peter on this one, or at least ask the question why those specs? 3pc, I get. Travel is generally easier with a shorter tube length. Why 6'6"? He has a specific carry case in mind? I'd go with tube length and make a rod to fit if that is the case. More importantly, why a 3wt? No easier to pack than a 5wt of the same length and section count far as I can tell. Is he looking merely to increase diversity in his collection? And prioritizing that over replicating the satisfaction he gets from the 2pc 5wt? OK, I guess, but I'd advise against it. Different type of fishing, maybe? That would make more sense. Or maybe a rod that he will use on small streams at home AND be able to bring with on travel? Could also be sensible. But a 3wt will not, in theory, cast the flies and handle the wind and other conditions that a 5wt will. Much more specialized. Back to the helping part (I hope), there are a couple of things you could do. You could use the Bokstrom 10-60 method in BOTPF. You could use Hexrod or similar computer program and change the numbers that way. You could kind of wing it and fudge 6 inches here and there to adjust the length and then shrink by 4% once to get it to a 4wt and then again to a 3wt. Or a different percentage, or constant thousandths if you prefer, but think about the tip v. butt % change in that case! Use some graph paper with an exaggerated scale a la Harms & Whittle to smooth things out. Just a guess, but the extra ferrule might help load the shorter rod, which could be helpful. (Chris Moore) Try Larry Tusoni's RodDNA......free to makers. You can translate and compare a LOT of tapers. (Tom Lucas) From time to time we have discussions about how, and to what extent, we ought to attribute a taper to the original designer (e.g. Payne 101 or similar). Further to our dimension discussion, I have to admit that I do NO attribution at all. This is partly because I do modify most (all, in fact) tapers according to my own peculiarities, and because even if i tried to build a copy of a Payne using planing forms on 5" centres and hand planes, I am sure my product would vary quite a lot from the Payne original. If someone asks me to build a Payne 101, I decline; however, I point out that I have in my stable a nice 7'6" five-weight that will probably suit, and loan it for a trial. My models are named after local streams and in this case the rod would be "The Macquarie". One of the most, to me, irritating things is to have a rod (mine or other makers’) judged on the 5" dimension in thousandths of an inch rather than on the casting characteristics of the rod. By not building copies, I feel my integrity is kept intact, and I am depriving the "measure it with a micrometer" brigade of their yardstick. I must confess that I tend to get a little terse with the "wrap counters". I have an acquaintance whose first (and only, really) reaction if you give him a fly, a spinner, say, is to count the turns of hackle and the number of wraps of ribbing material just because some fly dresser back in the 1930's said that was how it should be back when the determinant factor was likely to be the patchy length and quality of hackle feathers available rather than more arcane parameters of fly design. As I have said, I believe that we ought to be working as precisely as we can possibly manage, but ought not feel compelled to make every station match the designer's figures exactly - even if that designer is our self. I guess I am getting old and cranky! (Peter McKean) Bravo, Peter! Sometimes we get hung up on the "rocket science" of rod making. We can "paint by numbers" or use a blank canvas. As a famous rod maker on this site once shared with me..."at the end of the day, we're just making fishing poles". (Cliff Nigh) You know Pete, it's funny what you say about wrap counters and flies. I personally think a fly works best once it's been mauled a couple of times and really resist changing one that's working even when the the thing is literally falling apart. I mean, how do I know the trout doesn't like sick looking insects? Agree with the rod comments too. Like I wrote recently, with very few exceptions I doubt there is that much accuracy between individual rods by the original makes to get so hung up over. The main thing is assuming that what you're doing is working for you do what you do as accurately and repeatably as possible and it'll all be OK. (Tony Young) Peter, I think you've hit on something that many of us feel. If you are using your own taper, claim it. Sign your rod, date it, line size if you want. You never know who the future owner may be, and his or her appreciation for your work. That being said, when ever I have used Ralph Moon's tapers, I sign and date the rod, but credit him, as I would any other taper designer. I don't have an extensive collection of rods, but I thoroughly enjoy the rods I have, and I enjoy knowing the builders as well. I enjoy fishing the rods I have built myself as well, and if somebody else enjoys them that is fine also. Generally, I am going to fish the rod that I have in my hand, it may not be the best rod for the query, but it is the rod that I have, and I am going to make the best of it. I remember a fish some years ago, fishing an Eastern Sierra creek, best estimate was 14 lbs. I was fishing a 9 wt. because that was what was required to cast the fly. I also recall being disappointed that the fish was a Rainbow instead of a Brown, the audacity of some people. My ultimate disappointment was in myself for not using a lighter rod. None the less the fish gave all it had, I appreciated the give and take, but because I used such a heavy rod, the fish was released in a matter of minutes. With a lighter rod that would not have been the case, and the fish may not have survived. Now, I am going to upset a bunch of people and start another "grits" argument. I see little value in 0, 1, 2, and 3 wt rods. Sure they are fun to cast, particularly if there is no wind. But it is my opinion and only my opinion, that these rods border on cruel and unusual treatment to the fish we are pursuing. Landing a large fish with such a rod, means that it has to be played to exhaustion, there by greatly reducing its long term chance of survival. A small fish is being played to exhaustion for our own amusement. It is kind of like going after a deer with a .22. Some of these rods we build may last longer than we expected, and be enjoyed and appreciated by future owners, lets not make it impossible for them figure out the origin. (Greg Shockley) Come down to the East and West Forks of the San Gabriel River where "lunkers" are 10" and you will appreciate the value of ultra light fly rods. I agree that it is wrong to overplay a fish but it strikes me that this has more to do with the attitude of the fisherman and the size of the tippet than the girth of the rod or the weight of the line. (JW Healy) Not intended as a criticism of anyone...Maybe instead of emphasis on line weight, we ought to let "don't overplay the fish" be our guide and "too light" becomes obvious. Anywhere, every time. Designing rods to land fish quickly has been a stated goal of exactly one rodmaker I know of so far, and I have spent (happily) way too much time reading list serves, forums, and websites. He aims for 3 minutes or less. If there are more out there, hats off. Maybe mentioning it more explicitly to customers in our marketing efforts will help protect the resource? +1 on heavier tippet. (Chris Moore) John Juracek, who is well known fly fishing circles in the West Yellowstone area, has a 4-weight rod I made to match his request for a “butt yielding, tip resistant” rod (not parabolic). The rod flexes strongly down into the butt in much the same way a 3 or 2-weight would. John can land a large, strong fish with that rod so fast that it is unbelievable. My point? In most cases, it is the fisherman and not the rod that determines how quickly a fish is landed and released. (Tim Anderson) Good point, Tim. I could certainly use plenty of practice on big fish myself--an excuse to fish more perhaps? What I was trying to say, maybe a little too obliquely, was that if rodmakers *say* that their rods are designed to help land fish quickly, perhaps customers will be more inclined to believe that they have the capability and be more likely to do so. Jedi mind trick, see? All in good fun, but maybe help out the resource? The rod sounds great. John is a terrific caster, so that is high praise if he is enjoying your rod. The specs sound very Powell C taper-ish? I had to bow out of the HF trip this year due to a move. Perhaps I will have a chance to cast it in 2016. Have enjoyed your rods in previous years. (Chris Moore) I was & Lee's Ferry a couple weeks ago and had a 4 PC 5 wgt 7'6" rod that I just finished. I wanted to see how long after hookup I could land a trout. Now this is pretty heavy water, strong current. This was a 16-inch fish on 5x. From hookup to release less than 3 minutes. I think we underestimate our rods and leaders. (Bret Reiter) Bret, I couldn't agree more. I am damned sure we underestimate what they are capable of doing when used competently, and not treated as though they were made of balsawood. Another pet hate of mine is that large group of anglers who are trying for "cool" and who high-stick all their fish, and who wonder why they break their rods - graphite as well as cane and glass. It just puts all the stresses in all the wrong places! I fight my fish hard and fast, keeping the tip low and doing the heavy work with the butt, and using a lot of side-strain. I do not break rods. Well, not for that reason, nor very often. The last one I broke was a well-known brand of green graphite, and it busted out at the spigot ferrule. (Peter McKean)
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