Bamboo Tips - Tips Area |
|
< Home < Tips Area < Rod Design < Converting Section Count
Anyone having experience with converting a 2 piece rod into a one piece? Can I just use the numbers as is or should compensate.... (Danny Twang) It depends on what you want. If you absolutely want to preserve the original action, use Hexrod to compensate. If you don't, you will get some extra zip out of a rod that will still be lighter than the original. Personally, I would normally choose that option. If you have a step-down ferrule, that complicates things a bit. I would still use Hexrod to smooth things out in the center of the rod, but I would want to look at the stress curve and dimensions before commenting. (Tom Smithwick)
I have some questions about converting tapers from two to three piece, two to one piece, etc. What are the parameters some of you use when making such a conversion. For quite some time I thought the difference in dimension between similar tapers with different number of pieces was based on the stiffness of the ferrule either being added or removed. The more I read though, I now think that its based more on the weight of the ferrule. By adding in a ferrule you need to add more cane below the ferrule to carry the weight. Or conversely, by removing a ferrule you can remove more material in the butt to compensate. My question though is how do you decide how much to add or subtract. I'll give you an example that most people should be familiar with. Wayne's "Sir D" in his book is given in both two and three piece versions in various line weights and lengths. I'll focus on the 7' 4 wt. (top of page 182 in my copy of his book). The dimensions for both the two and three piece are identical for stations 0-25, which makes sense since there wouldn't be a ferrule encountered until 28 inches. Starting at station 30 though the 3 piece begins to get progressively larger. The dimensions for the two tapers are listed below. station 2 piece 3 piece 30 .152 .154 The difference starts out small and gets bigger until the ferrule point of the two piece. It slows down then (because there is no ferrule at 47 inches in the 3 piece) and picks up again after the final ferrule in the 3 piece. Converting this rod is not a big deal because I have a book that lists the taper. What if I didn't have a book? I tried using hexrod to change the same 2 piece Sir D into a three piece and came up with different numbers. Not vastly different, but still different. What's more, when I told Hexrod to use truncated ferrules I got still different numbers. One of the reasons I even bring this up is that this winter I want to try to make a longer 1 piece rod as well as a rod using a FIBH ferrule (integrated bamboo ferrules). Lets say I want to make a 1 piece Sir D. Should I just run the 2 piece through hexrod? Or are there other factors I should keep in mind? For rods with bamboo ferrules (which are substantially lighter than metal ferrules) what adjustments should I make? Split the difference between a 1 and 2 piece taper? Any help, insights, or discussion would be great. I'd like to learn how to balance the use the a computer program with being able to use my head. (Aaron Gaffney) When comparing Wayne's 3 piece taper with the 3 piece taper you get from Hexrod, make sure that the two are using the same size ferrules. The Hexrod programs will make an assumption as to the proper size ferrules but the builder must be the final judge. The stress calculations that Hexrod performs depend on the weight of all the components (cane, ferrules, line, varnish & guides), so the sizes of the ferrules used will change the stress curve. Going to truncated ferrules will also change things. Going to cane ferrules, well you should try to find out their weight if you are going to use Hexrod to help build the taper. I have no idea if cane ferrules are lighter than a truncated NS ferrule or not. (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive)
I just finished Wayne C's 7042, but made it a 4 piece and impregnated it instead of varnish. I test cast it with a regular 4 weight line (Orvis I believe), and it really didn't feel right (been thinking more about feel after Jerry's recent posts). I then strung up a 5 weight line (Cortland Sylk), and that was much better. The rod loaded more effectively, and I had tighter loops and hauling was a pleasure. My question is - why would my rod, which is slated to handle a 4 weight line just fine, need a 5 weight? Was it the conversion to a 4 piece, or because it was impregnated, or maybe both? Or was it the different line types? I don't know enough about lines to understand how rod design (besides taper manipulation) affect its ability to cast one line better than another (given the same caster of course). Thanks for any thoughts you may have. (Louis DeVos) Adding nickel silver ferrules will stiffen a rod, so that is a possible reason for the better casting with a 5-weight line. The added weight further toward the tip also will change the casting characteristics. Impregnating might have produced some swelling of the cane. That, too, could change the casting properties. I know what my solution would be: just use a 5 weight line with the rod! (Tim Anderson) You could have used RodDNA to convert the rod to a 4 piece and it would have recalculated the new dimensions while holding the stresses the same. (Larry Tusoni) The Cattanach 7042 is a 'tippy rod'. The line weight designation relies to a large extent on that tippiness. I'd say the line weight change is almost certainly the result of adding the top ferrule. The stiffness of this ferrule would buttress, and thus reduce, the high stress point in the tip making the tip stiffer. (Steve Dugmore) I’ve recently done some calculations that show that adding a ferrule increases the stiffness 3X over what it would be without any. BUT that’s over only about 2” of rod length. My deflection program shows that extra stiffness to be the equivalent of a little less than 1/2 line wt increase. Adding the weight of 3 ferrules instead of one has the effect of reducing the stiffness by a little less than 1/2 line wt, so they about cancel out. I don’t have any information on the effect of impregnation on stiffness. Intuitively, you would say that adding material to the rod (impregnant) would stiffen it, but the added weight of the impregnant would tend to counteract the stiffness. Non-reinforced plastic-like materials don’t have anywhere near the mechanical properties that bamboo has so the impregnant is unlikely to increase the stiffness much. I’ve measured enough difference in bamboo Modulus of Elasticity to say that you could easily find 1/2 line wt difference from one culm to another. Don’t be insulted: Did you hit your numbers? If you wound up oversized, that could make the difference. (Al Baldauski) The answer... butt over tip, bamboo ferrules... simple and smooth, very slight increase in weight and moderate increase in stiffness. Makes the rod react closer to a one-piece and the sensitivity is amazing. Well, OK, just my humble opinion, but I am really sold on them. (Mike St. Clair) Has anyone weighed the Cortland Sylk lines? Just in terms of feel, I have always thought they were light for their line weight designation. Again, only going by feel, I think of a 5 weight Sylk line as being a 4 1/2 weight. (Dan Zimmerlin) Agreed. I have a 5DT Sylk and does seem a tad light. Definitely thinner diameter than usual modern lines. I've not weighed it, only judging by feel. Do like the way it shoots, good lack of memory right out of the box, and works well through smaller guides. just my opinion. Have no idea about durability yet, as the line is fairly new. I'd also be interested in hearing from anyone who has actually weighed any of these lines. (Bob Brockett)
How should one approach modifying the taper of a 2-piece rod when converting it to a 3 piece? Assuming nickel silver ferrules. (Steve Dugmore) It's pretty straight forward:
I am aware of the Hexrod option but am curious to know how those who design rods approach it in principle. Personally I increase the midsection a bit (in order to propel the second ferrule) and then also increase the butt slightly (to propel the larger ferrule at the butt as well as the second ferrule). but I am not always happy with the result. I still generally prefer the feel of the 2 piece so was wondering what other approaches there might be. (Steve Dugmore) Hexrod or any rod program should first take out the bamboo needed for the ferrule on the two-piece rod making the rod a one piece, then they add the bamboo necessary for the top ferrule, this starts at the top ferrule and continues to the end of the butt. Next it should add in the bamboo necessary to compensate for the second ferrule starting at the second ferrule to the end of the butt. A lot of folks use truncated ferrules when converting. I'm not sure what you mean when you say you add a little bit for each ferrule, how much is a little bit? Also what is it you don't like about the feel when you convert to the 3-piece? Last you should be aware that all rod programs will not give you exactly the same results, but for conversion to three piece, they should be close enough. I don't make many three piece rods but, maybe those who do will comment on their experiences. (Bob Norwood) I should have added that care should be taken when changing or adding ferrules to insure that they don't interfere with the designed rod action. If this happens a small modification of the taper around the new ferrules may help to keep the rod at or near the original design. Just a thought. (Bob Norwood)
I am interested in any thoughts or approaches used when making a 4-piece rod from a 2-piece taper. I made a Dickerson 7613 in a 4-piece format last year by adjusting the taper at the 1st and 3rd ferrules in (smaller) a bit to compensate for the stiffness of the extra ferrules, and I used the lighter Japanese Hariki short ferrules to save weight. I've used the rod a fair amount and am happy with it (though it may be a touch fuller acting than a previous 7613 I made, but still on the faster side. Not a bad thing), but would now like to try the Cattanach Sir D in a 4-piece format, and was wondering if anyone had any thoughts, or if the above approach makes sense when run through Hexrod, etc? Fortunately, it looks like the 3rd ferrule will be just after the hinge. (Tom Park) I might get shot down for this but my advice is just run the taper through hexrod and make it a 4 pce (or just recalculate section lengths for the additional ferrules). At the most flatten out the hinges first as these will probably be negated by the additional ferrules anyway. The reason I say so is that whatever you do to a 2pce taper to make it a 4pce it is exceedingly unlikely it will have the same feel as the 2 pce. So you are dealing with a new rod regardless. Without really knowing what the new rod will feel like until you make it and try it, you might as well go ahead and make it to find out. THEN tweak/design it on the next rod using your understanding of the feel and how this relates to the stress curves, etc. (Stephen Dugmore) I have built seven 4-piece Sir D's modified using Hexrod. Four of them 7 ft. 4 wt. and three 7 1/2 ft. 5 wt. I can't say they feel the same as the corresponding 2-piece Sir D's, but very similar. I am happy with the results. Try it and let us know what you think. (Dan Zimmerlin) I have been out of pocket of late. In the process of retiring at the end of this academic year. Haven't even been in my shop other than to clean it up. The last two rod I made were both Dickerson 7613 7'6" rods that I simply cut into 4 equal section and got the needed ferrules from CSE.I fished both rods 2 summers ago in Montana. They were fast, or relatively so and I was pleased with their performance. I believe I will continue to make 4 piece rods again, once I get back to work. The muses are fast asleep and I am having a difficult time waking the up. (Phil Crangi I will try to crank up my Hexrod skills, but did Hexrod show any variation in the taper at the 1st and 3rd ferrules on the Sir D? Or is it more complicated than that? I greatly appreciate all the input, and will try a few rods on this format to get a feel for what is happening as suggested. (Tom Park) I started making 4 piece rods a number of years ago. I juts took what I considered fast tapers and cut them into 4 pieces. A number of people who cast them liked them so much I ended up giving them away or selling them even though they were my travel fishing rods.The ones I liked the most were the 7613 and a fast version of the Perfectionist. I am about to cut a 9 footer into 4 species as well. Make things so easy to transport.I have not changed the tapers and it does make them slower and in many cases smoother to my feel. (Gordon Koppin) I made a 4-piece Para 13 a while back & I was amazed at how well it cast after the conversion. Maybe a little slower than the 2 piece but still an awesome rod to cast. What line weight are you trying to achieve? Will you hollow the joints? (Gary Young) I am looking @ both 5 & 6 weight rods. I am going to try both hollw built & solid shaft blanks & see what I think. (Bret Reiter) I built half a dozen hollow rods, four of them scalloped from side to side with dams left; and the other two fluted courtesy of a MHM fluting tool.I was happy with the work and with the structural soundness of the rods, but to be perfectly frank I couldn't really see that all the fiddling about it was worth it.People make a lot of the weight, but I am a 71-year-old with ankylosing spondylitis and arthritis, and the weight of a solid rod just doesn't bother me.I get good crisp action with solid designs. Building some hollow was interesting, but I won't be doing any more. (Peter McKean)
I have built a 9016 9' 8wt as a two-piece rod. Been challenging but looks good. Two handed handle and have wrapped the guides with a couple coats of helmsman. Now I am wondering if I should change to 3 pc? What does the group suggest? Can I just cut the tip and the butt off and make a new mid section? Or do you think it is ok to leave as two piece? (Jim Miller) Don’t fix what aint broken! Rather make a 3 piece next time if you feel you might prefer it as a 3 piece. If you feel you absolutely have to modify it, I would suggest you rather make it a 4 piece by cutting the tip and butt midway and adding ferrules there. (Stephen Dugmore) I agree - make a second as a 3 piece and compare them. But, do that next winter and fish the one you have all summer :) (Greg Dawson)
|
