Bamboo Tips - Tips Area |
|
< Home < Tips Area < Planing < Final < Accuracy
How close is close enough for your final planing? I finished my butt section earlier this week and was either right on or ± .002" (mostly under toward the thin end). I figured that if I goofed with the strips any more, I was going to do more harm than good. (Scott Turner) Well, as you could only remove further material, it was a good idea to stop. :-) Truth is, accuracy of this phase must be viewed in light of ultimate ramifications. For instance, if that shallow spot is matched by heavier spots on adjacent strips, the station might be glued into a position which makes the section stiff there. Another ramification is that your taper might behave as a faster taper, at closer range. In fact, there's a place for a rod like that. In any case, working with wood to tolerances that close is damn good work by any usual yardstick. But always you are after accuracy, or you aren't building what you want to build. The faster your tapers, the more something else is important however -- and that is where an intersection is manifested, below which bending cannot dramatically increase. Here, although accuracy, and particularly weak spots are highly important (in the latter case, to eliminate), design is far more important. After all, the design of many rods deviates from an ideal far more than two thousandths. (Mike Montagne) Well, check out some of the classic rodmakers rods and I think you will find that within ±.002" is not too bad at all and is certain to cast pretty close to what you modeled the taper after. There are some modern rodmakers who think that ± .001 is the target, and I've gotten that close before all the way up and down the rod (well, maybe not toward the butt section). I think you are doing fine. Don't sweat it. (Rick Crenshaw) Oops! I see that you are talking strips, not completed rod! My bad. ±.002 on each strip means you might be off as much as .005 or .006 by the time you finish glue up. If you are undersized by .002", you need to just go ahead and glue up what you have. You might only be off by .002 or .003" if you are careful in removing the glue after cure. You really ought to be able to get close to .001" on your strips if you set your forms right and scrape carefully. Still ought to be a pretty close rep of a classic taper if you are modeling after one of those. Some of those rods vary quite a bit. (Rick Crenshaw)
I know there will probably be a bunch of opinions on this one. But it seems to me that hitting tapers within .004" works just fine as far as action goes. That being said I bet that only holds true if the taper drop maintains the 0.004". For instance a rod built 0.004" over its entire length would be more likely to resemble the target taper than one that is 0.004" over at one station, then right on at another, then 0.004" over at the next. Is it better to be consistently wrong than occasionally right? (Lee Orr) I'll go for consistently wrong. LOL. The taper at least will mimic what you intended to build with the only possible negative outcome being that the rod may be a touch quicker in action or at worst, perhaps one line weight heavier(being consistently over). I do have to say I have monkeyed with a few tapers by adding or subtracting a few thousandths here and there and have made up a few fairly interesting tapers that way. I averaged a couple Dickersons of different lengths a couple years ago and came up with a real nice 7'9" 5 wt taper. I guess my answer would be: what are you attempting? A new taper or a copy or imitation of the existing one? If a copy then the consistent few thousandths over will do (with the earlier caveat). If a new or different type action then a few thousandths here and there may accomplish that. How's that for a "no answer type answer"? (Dewey Hildebrand) I'm sure you will agree that it is better to be consistently right. :-) Much better than consistently wrong or occasionally right. That said, I think once a person makes a few rods he comes to grips with some combination of techniques that makes hitting the desired numbers consistently a reality. (Harry Boyd) True. I'm just curious as to which accuracy is more important. Target dimensions or maintaining the taper drop. Granted hitting both is the best situation. I can't help but think that taper drop is more important. After all 0.002" over at one station and 0.002" under at the next makes the taper off 0.004" not 0.002" (Lee Orr) You will have to specify where on the rod the differences are. .002 off on the butt section - no difference. .002 off near the tip section - big difference. (Darryl Hayashida)
Well, I am on my first rod and am nearing the final scraping of the splines for the butt section. I have only cut myself once so far. Its been scary but I kept going and things are coming together nicely, so far. Question: What is a reasonable tolerance for planing, scraping, sanding to final dimensions? The Archives contain one email that says .004 was acceptable for Garrison. Is this good enough? (Dave Gerich) Aim for .001. Garrison's book makes that very, very clear. See his section on "Final Planing", page 78 in my edition of A MASTERS GUIDE... (First edition, 1977). See especially the statement on p. 80, 'Take your micrometer in hand and mic the strips at the marks, checking the results against the calculated taper for the rod you have decided to build. You may find that some strips have not been planed to the proper diameter by one or two thousandths, and this is the time these errors should be corrected.' I am sure there are other quotations I could find in his book and report to you and others on this topic, but for now this one will do. I regard this statement of Garrison's as one which should be the rod builder's goal at all times. I have come to disagree with Everett Garrison on many topics from hand planing, node placement, tapers, binding, Super - Z ferrules, wrap colors (just to name a few) but his observations on the subject of planing accuracy and on resorcinol glue are two topics on which he was absolutely correct and with which I will never argue. I have made up a copy of the above statement from Garrison's book and placed it above my planing bench just to remind me. (David Parker) The process I have found which has resulted in the greatest accuracy for me is to (1) plane the strips to 0.030" over, then (2) plane to final dimensions, then (3) mark and measure the strips at each station -I have found that they will be .001-.003" over target. I then set the forms for 0.001" under the final dimension. My last blank was spot on (.001-.002") at each station. (Lee Orr) I'd urge you to strive for the best tolerances you can achieve without resorting to scrapping your efforts. Remember that Garrison was at best a perfectionist, and at worst OCD (obsessive-compulsive disorder). First rods are always a learning experience. I drag my first rod to every show I do as a way to show folks that anyone with reasonable patience, average manual dexterity, and the ability to read directions can build a workable fly rod. To answer your question, keeping one's triangles as close to equilateral as possible is more important in making a good rod than striving to be within "x" thousandths of an inch of your target dimensions. If you keep the triangles within a few thousandths of equilateral, your rod will be just fine. For tips, I measure each station three times, from each flat to each apex, and try to make certain the average of the three measurements at each station measures within .001" of my desired taper. If any of the measurements for tips is out more than .003", I start over. For butts, I shoot for .002" and .004". Of course, I sell a rod now and then and thus am forced to be more anal than some. Incidentally, except to remove a little enamel from the strips I no longer use a scraper -- though many good rod makers swear by them. I find that with a very sharp, well-adjusted plane I can take the strips right down to the forms and don't have to deal with the chatter and fuzzy edges that I always got with my poor technique with a scraper. (Harry Boyd) Must say, Harry, how much I agree with you on the scraper statement. I find that my L-N scraper is a very valuable tool, and I would hate to be without it; but I find it is useful only on the enamel surface of the strips, and VERY occasionally for a bit of resurrecting of a "chipping" node. I think that the irregular surface and furry edges left by even a beautifully sharp scraper is unacceptable, and likely, even, to contribute to visible glue lines. To those who haven't performed the "feel test", just try running your fingers along a surface that you have "finished" with a scraper. I'll bet that your first action after doing this is to take out a properly sharpened plane and use it on a very fine setting to try to fix the surface. Which will probably work! And the reason for the parentheses back when talking about "chipping nodes" is that, IMHO, if you use a properly sharpened and tuned plane, and prepare your strips adequately in the first place, you are quite unlikely to encounter this particular problem in any case. (Peter McKean) My experience is that when ever I try the "feel test" I end up breaking out the Band Aids! (Doug Easton) Indeed, this is key to avoiding gaps between strips, which, at best, are a pain in the butt to correct, and, at worst, will mean remaking one or more strips. Always a good idea to measure the flat-to-apex dimensions before your strip reaches its final position in the form, so you have enough left on the strip to make corrections, if necessary. As Harry said, if you keep your strips equilateral within a couple thousandths, it'll all work out nicely. As far as dimensions go, if you must err, err to the large side. Small corrections in dimension can be made in final sanding, and if you are within +0.004" or thereabout of the desired diameter all the way 'round at each station, you can bring it in with judicious application of the sanding block (measure often! :-) , and not cut too deeply (IMHO) into the power fibers. Also realize that you will gain in diameter due to the glue between the splines, anywhere from 0.002-0.006" or more, depending on the glue and your technique. If you set the form to the exact spline dimensions, you will most likely come out somewhat oversize when you unbind and clean the excess glue off the section. (Todd Enders) Having earned a living making violins for years I have to say that the worst glue joint you can come up with is a sanded glue joint. You will never have clean wood with sand paper, it always leaves fuzzies. After sanding either wood or bamboo wet it with a damp sponge and then let it dry, that's your gluing surface- thousands of short fibers. Your glue joint will never be good gluing short fibers to short fibers. I think that to me the problem is that people are using the wrong angle on their scrapers. A scraper is a mini plane blade and should cleave the wood/bamboo and leave a glass like surface. If you have chatters or fuzzies or anything other that a clean surface you don't have the proper angle on your scraper and you don't have it sharpened correctly. There is no way that sand paper can ever match a scraped surface done correctly, gleams like a freshly planed surface done with a sharp plane blade. Sand paper, rocks glued to paper. (Patrick Coffey) As I stated before, I don't use a scraper to remove material from strips down to the proper dimensions... but I'd like to know more about how to set up a bodied scraper for its most efficient use. Do you think you might offer a few pointers about angles, sharpening, etc.? (Harry Boyd) I am all ears, would like to hear about the proper way to use the 212. I would rather use it than have it sitting on the shelf. (Tony Spezio)
I just finished blank number one, a 7' 6" Martha Marie. While not perfect, I am quite pleased with the lack (mostly) of glue lines for a first effort. Stunned actually. Here are the measurements: Goals and Actual on all three sides: Station Goal Actual 1 .070 .076 .074 .075 Questions. Would this rod be worth finishing out? Would it perform anywhere near what it is supposed to be? I have already proven I cannot grow tomatoes worth a damn. Stations #1 & 3 are way over specs, is it possible to sand them down some to meet specs and still be good? Other stations exhibit a difference from flat to flat of up to 8 thousandths, does this difference render the rod substantially out of sync? Don't worry about hurting my feelings, I will never complete this rod as the cane is from Pier 1 Imports, $8.00 for a culm and a half. This is just for practice. (Steve Shelton) Pretty darn good, I'd say. If you wanted to sand a bit off to bring some of the stations even closer, you're only talking about .003" on a side, so unless you are already into the power fibers you aren't likely to hurt anything. (.003" off each flat = .006" total.) I'd guess that any of the lower end commercial rods from 50 years ago didn't hit the numbers any better than that, and maybe not the high end ones either. (Neil Savage) Actually, even if you WERE already into the power fibers, sanding to bring all flats into conformity with the target dimensions would cause no harm. If the rod is oversized by some small amount, it will be just that much "faster" and heavier than designed. So, while sanding into power fibers is generally a big no-no, doing so on a finished rod that is only barely oversized in a couple areas will only make the rod cast as intended. Not to worry -- the next ones you build will be closer. (Bill Harms) Good job, especially for your first rod. we have all had rods that came out not at the specs we wanted. (Patrick Coffey) Of course finish it! I wouldn't even worry about the stations that are over. The fist one I am assuming is the very tip? It's going to be under the tip top, and the tubes on tip tops are usually about an inch long, so that one won't affect anything. The third one is close enough and since the stations on either side are right on even if you sand down the third station to specs you won't notice any difference. (Darryl Hayashida) I finished a 7’ - 6”, 6 wt. Martha Marie a month or two ago (I used Chris Obuchowski’s submission to Hex Rod). I was "over" on several stations. I'll have to dig up my "after" measurements, but I think you were a lot closer than I ended up being on the taper measurements. Did you make the 5 wt. or 6 wt. version of this rod? Despite being "over" in areas, the rod is very pleasing to cast (OK, better than pleasing - a certified casting instructor friend at a fly show double hauled the entire 109' of WF line out off the rod – the “ping” of the leader’s nail knot against the sign above the concession stand was pretty darn neat!). Chris and I cast his 6 wt. Martha Marie (VERY close to the measurements on Hex rod) alongside of my “over” MM on the Deschutes last month and they cast very similarly. As a marginal caster, I couldn’t tell much if any difference. So sometimes you just get lucky with your mistakes. You are going to love this rod. I have a double taper on it right now, but I’m going to replace that with a weight forward so the close in casting will be slightly easier. The Martha Marie (MM) is a rocket for casting into the wind and/or casting larger flies such as bass flies (Paul and Martha Young used this rod for bass fishing from what I understand). The rod handles larger fish very well, but also protects the tippet well enough. I’d be confident that I could turn a summer Steelhead on this rod if push came to shove. In the late summer, while fishing the Deschutes for trout, it’s not uncommon to attach your fly into the mouth of a “screaming to the ocean” summer Steelhead! (Scott Turner) I think your numbers are what they are, just numbers. Go and finish that rod and go and fish it. It may be a little off, but you will never know unless you go and fish it. Go get some cheap components, finish it and at the very least go and cast it. I think that too often we get hung up by the numbers. A trout on the other end will never know if your tip is off by a few thousandths. I remember seeing a rod once that was made by a pretty famous rodmaker and it was one of his earlier efforts. It was not the prettiest thing, it was made from Calcutta cane, but it still is one of the nicest rods I have ever cast. Beauty is in the eye of the caster. You did it. Celebrate and use the rod, learn from it, your next rod will be much different. (Mark Babiy) A lot better than my first rod which was supposed to be a three weight and turned out a 4 wt. and I am still catching fish on it! Made rod number 2 using the same taper and it came out a lot better, a nice three weight. I have been using Tony’s idea of scraping the final few thousands with a razor blade and so far haven’t come up with a better solution. Keeps the measurements closer for me. (Gary Jones) Go for it. You probably will be very happy and proud of the rod. Although I am far from an expert the numbers look close enough that I think you should finish the rod and fish it. My first rod turned out to be a buggy whip which was unfishable but the experience building it was priceless and led to many years of a fine hobby. (Jack Follweiler) To answer the question others seem to have skipped, you can sand down the station that are oversized to get to the final dimensions. You can probably take off as much as 10 thousandths without compromising the strength of the rod much. A lot of makers take off more than that at the nodes. However, I would never recommend that anyone ever use cane they wouldn't finish out and fish. When Tonkin cane costs ~ $15 per culm, it simply isn't worth the time to practice on cane you would not use. When I started out, about 7 years ago, I bought a bundle of 10 culms from Andy Royer. I picked out the worst one and decided to use that one for practice. First I practiced flaming and splitting, and to my surprise I got quite a few useable strips. Then I practiced straightening nodes, rough planing, and heat treating. Then I made my final forms and practiced final planing, gluing up, straightening. I was somewhat surprised that each step worked out more or less OK and I wound up with a 7' 2/2 4 wt that far exceeded my expectations for a first rod. I finished that rod out, and now I practice fishing with it a couple of times each year. I expect that the rod will outlast me. You might want to reconsider finishing the rod. Before I ever got involved in bamboo rodmaking, I bought a 6' piece of bamboo at a local hardware store for something like $3. It was only about 1.5" in diameter and has pretty short internodes. I still have a chunk of it around, and I pretty sure it's Tonkin cane and it has very dense power fibers. I'm sure it would have made a good rod. (Robert Kope) My first rod (a 5'6" spinning rod), was from a Tiki Yard Torch. It was short, so I thought all I could make was a spinning rod. I was using George Leonard Herter's book. The shortest fly rod taper in the that book was 7 feet. It said to take a fly rod taper and cut off each end to make a spinning rod. What a mess, but I caught fish with it and it didn't break. (David Dziadosz) A hearty thank you to all of you responding to my request for information. All responses were very uplifting to someone who so far has learned the beginning of this process from reading books, reading this board, and reading Clark's site. Everyone says don't worry about the cane, finish it and fish it. Well, the cane is really a problem, but it was intentional. Somewhere I read that you can buy cheap cane from a non-rodmaking source and use it to practice. That is what I did. Pier 1 Imports is a home furnishings store selling imported items, most from China and the Middle East. They had cane, three 6' pieces about 2" in diameter. However, power fibers and pith rarely measured more than .200". All for $8.00. I knew that there would be a really steep learning curve, and that #2 would (should) be measurably better than #1. Therefore, #1 will become some really sexy fly tying bodkins, or maybe even some ferrule plugs. No matter what, I have no regrets for doing it this way. (Steve Shelton)
I have a question, I guess it is a senior moment for me. I got a strip for butt section. At the end I got .160, and .160 and .140 and I want to wind up with .150. What do I do? Do I plane on the .140 side or on the .160 side? (Lew Boyko) You can't add to the .140, it is what it is. All you can-do is plane down the other two sides where they meet to .140. (John Smith) Plane down the two .160 sides and if necessary end up with a hollow lower butt. It will be fine under the handle. (Bob Norwood) Even if you plane the .160 sides down to .150 and don't lean the plane, you will make the .140 smaller. The smaller side also means the 3 angles don’t atch. If the .140 is the enamel side, then the rod will not be the same dimension from flat to flat all around the rod. If the .140 is a pith side, then the strip won't flush up with the other strips when glued and bound. Maybe it doesn't matter but personally, I would save the strips for another rod. (John Smith) If this problem is just at the butt end of the butt section, and the rest of the dimensions are OK, I would cobble it up as best can be done and glue it up. You will be gluing a nice stiff reel seat over it, which will totally dominate the stiffness there no matter what the bamboo dimensions are, correct or off. And of course it will cover it up. Just resolve to be more careful next time. (Mike McGuire)
Working on an FE Thomas 3 weight tips. My individual strip measurements have been good. The tip measurement is supposed to be .50 thousandths. After glue up, I have had the tips measure at .55 to .57. I have used Titebond and Epon. Should I be undersizing the individual strips? Measurements from the butt up are very close to gaol but, tips get oversized. Ideas? If goal at tip is .25 then should I plane each .002 less? (Mike ??) I leave a glue allowance of .004 for TB III and plane a few thou off the pith side apex. The size of the allowance also depends on how thick you put the glue on. TB III seems to get thicker the older it gets. (JW Healy) Is that .004 per strip or from final dimensions? Just had some oversized tips myself. (Henry Mitchell) With regard to use of Epon, I have found planing .002 under on each strip for tip sections has yielded the best results (for me). Most importantly, remember to have fun. Apparently, some lose both hair and sleep over "hitting the numbers." If that counts as a strategy for doing good work, I'll pass! (Bob Brockett) Yes. If the taper calls for a dimension of 0.10. I set the form to 10/2 -.004 = 0.046. I have also increased the planing of the pith apex from 3 passes at approx 1/1000 to 5. For me the biggest variable is how thick the glue is applied. On the rod I am working on now the butt section is .004 over at each of the five bottom stations and .002 at each of the top. (JW Healy) 0.002 - 0.004 over? Don't forget there is precision sandpaper for the 0.002 and precision files for everything over that. If you are trying to hit a published taper that was measured from a rod keep in mind that those numbers are most likely no better than pus or minus 0.005 and probably worse than that from the original. Measure with a micrometer, cut with an axe. (Jerry Drake) Well, Jerry, when you're making them for fun, as I am, part of the challenge is seeing how close you can get to the target numbers. If you're making them for profit that's a different story. Someone making rods as a business couldn't possibly take the time it takes me to make a rod. And yes, precision sand paper is particularly useful once the rod is glued up. (JW Healy) When you say your individual strip measurements have been good, does this mean you are measuring them all three ways to verify they are equilateral triangles? If not that's where some of your problem may be coming from. But assuming you are good that way, do you bind them up dry and measure the assembled rod? Even if the strip measurements have been good, this can show problems easy to fix at this stage, but fixable after gluing only at the expense of surface power fibers. What can also help is running a strip of sandpaper up and town the inner apex of each strip to provide a little clearance. Four hours of heat setting of epon as recommended on the bottle will cook most of the moisture out of the rod and temporarily shrink it a couple or three thousandths which in a few days it will recover. When you measure has an effect. (Mike McGuire) An always interesting question. When you measure, or take the given measurements for a rod, do you know how thick the glue was on the original? When you compute a rod are you including the glue? Do you know what the moe/moi of the glue (either)? Certainly the glue is included in the rod but what effect does it have? When you cast you’re casting bamboo. All of the computations and feel have to do with the amount of bamboo in the rod. If your strips are "on the numbers" then the finished dimensions are almost irrelevant.... If you alter the amount of bamboo in the rod, then you are not making the rod you think you are... Probably doesn't matter, but… (Jerry Foster) That's a good point Jerry. Did the tapers listed in Hexrod and RodDNA etc take glue thickness into account and deduct from the measurements taken on rods? Varnish thickness certainly, but I've never heard mention of a deduction for glue thickness before with listed tapers. Anybody know for sure? (Norm Knieriem) Your points are well taken but I disagree with your last statement: If your strips are "on the numbers" then the finished dimensions are almost irrelevant. The glue IS almost irrelevant as far as its mechanical properties are concerned BUT IF the glue line is so thick that it increases the diameter of the finished rod then you have significantly increased the moment of inertia (stiffness) because you are moving the bamboo components out to a larger diameter further from the neutral axis. At a point on the butt measuring 0.250 dia an increase of 0.004 increases the MOI by 6.5%. At a point on a tip section measuring 0.100 dia an increase of 0.002 increases the MOI by 8.2%. THAT is NOT irrelevant! On most tapers, those kinds of increases represent more than one-line weight increase. (Al Baldauski) How did I know you were going to make that argument... science. However, as a practical matter, I'll call it my void beam theory, most of this moi deals with the same mass equivalency, bamboo. My point is easer to see if you plane .002 of each strip, do you have the same moi when you fill the void with adhesive? My point is, you can chase the numbers or decide that the strip measurements are what the target should be... No matter what you do the stick will usually increase in dimension after you glue it up. When you do run your program and get a set of numbers do you automatically deduct some number to account for the glue? Sam, and Al.. Sam, you asked a question about putting different tip and butt geometry's together. In theory (right Al) if the taper is done correctly for each section it should make no difference at all... But does the glue make a difference? Is there really a difference between a quad and a hex rod? If there is the only difference is the number of glue lines. No matter how you cut it (no pun) this is not a homogeneous instrument. (both in the bamboo and the glue) And Al, the 1/2 theoretical line weight difference is compensated for by two things. If it is true, then you can cast a few more feet of line, and I know you hate, or don't believe this part, but the angler automatically compensates by the use of a little more, or a little less force. Or, the sweet spot moves a little bit... (Jerry Foster) The mass and cross section of the glue is insignificant. The mass of the bamboo is certainly key. If you move the cross section of the bamboo out from the neutral axis you increase the stiffness but not the mass. If you remove 0.002 THEN space the strips to the target diameter with a thick glue line you'd actually reduced the MOI and mass but not by much. If the overall difference is 1/2-line weight, I agree, most casters will automatically correct for it with 5 feet of line more/less outside the rod without realizing it. So practically it may not be important. But if you're trying to reproduce a rod you cast and liked then you should strive to hit the number ------ all the other variables notwithstanding. All of the practical and theoretical considerations aside, my point is: a few thou here or there will make a noticeable difference in a side-by-side test. Maybe not in my hands but to very good casters. (Al Baldauski) Sorry. I meant to say: "those kinds of increases represent more than 1/2-line weight increase." (Al Baldauski) Seems to me there are some many potential variables the best we can hope for is to try and keep our techniques as much the same as possible rod to rod and learn from each one we produce. Possible variables include, density of the bamboo, techniques in flattening nodes or taking them out al together, heat treating schedule, temperature variations with in the oven used for heat treatment, glue used, tension in binder, techniques in finishing the enamel side after glue up, accuracy of the taper and flat to flat measurements, where you decide to cut the blank, varnish used, number of coats of varnish and I am sure many more if you just think about it. I am still amazed that even so, when you copy a rod it feels much like the rod you copied even though I am sure the original maker did many things differently than I do. A Payne feels like a Payne and a Dickerson like a Dickerson. There have of course been some notable exceptions over the years in my rod making but sometime for the better but also for the worse. Those rods are good for the learning experience even so. (Ron Kubica) The reason I occasionally dabble in these conversations is to hopefully interest some of you into looking a little more into rod design than just copying someone else's rods. None of this is absolute science. Sorry Al, the software we use, and the understanding we get from it are just guidelines. As Ron pointed out there are too many variables and unknowns to be absolute. But all of Al's points are completely valid, of course. And as Ron stated the key to making repeatable rods is process. You must have all the craft of making a rod under control. Now as to our small quibble Al. Sorry about my oversight in the OD of the rod when cloning Al. I just don't think about changing someone else's rods. Using the software I use I did a couple of test designs. As a base I used a Dickerson 7012. Some basic design principles I use:
You will notice, of course, that I didn't state any numbers with the exception of the .004 change. That's because I design by deflection only, so the numbers almost don't matter. Of course they do when I cut the rod, but in the design stage they are just a bunch of numbers. (Jerry Foster) I'm not sure what you mean by change in angle, but if a change in line weight is 6 degrees, I am surprised that .004" resulted on only .9 degrees. I would have thought that would cause close to a line weight change. (Bill Lamberson) Yes, it did seem small so I checked it on a Garrison and .004 only makes .7 deg change on the 193. The amount of bamboo you have to add to get a line change is significantly more than I expected at first... But after changing a lot of my rods I began to trust the numbers more. .002 in the tip to .016 in the butts on some rods. The major thing that changing line weights using Stress type math was that it does change the line weight but it does not compensate for Speed. This gives you typically a softer rod and makes it more difficult to generate a rod "family". The rod deflection angle is the angle formed from the butt end of the rod to the tip when fully deflected. (Jerry Foster) There appear to be two major aspects to a rod, or the way we feel them.
This is the way the stress or incremental deflection graph looks. The general shape of what you see. It is the thing that separates rods we like from rods we don't where speed and ferrules and guide spacing and all the other aspects of rod construction are proper and equal. The grip can make or break a rod as can the distance to the stripping guide. Personal preference. The two things a client should have a say in. Does that help Bill? I know you know this already. (Jerry Foster) "The grip can make or break a rod as can the distance to the stripping guide." So the question that should be asked; If one builds a perfect blank c/w perfect cane to perfect measurements and along comes the not so perfect guide placment or strip guide location or handle shape/length. What are the criteria for guide placement, strip guide location or handle shape/length to make the rod "perfect"? Are there not some rules of thumb that can be applied? Like - strip guide is not less than 20 or greater than 26" from the butt. Would those simple "rules of thumb" reduce the chances of building a lemon? (Don Anderson)
I continue to have some problems with getting over-sized rods even though I am ultra careful to assure that each of the hex's are of the right dimension before gluing. This manifests itself in the butt section of the rod, not the tips. And the oversize progresses as I go lower on the rod so that in the grip area, I can be 9 to 13 thousandths too big. I am thinking that my binder does not as easily squeeze the excess glue out of the butts as it does the tips, and thus I attribute the oversize to excess glue. If anyone wants to take issue with that conclusion, I am all ears. But here is my real question: An obvious solution to the over-sized butt (the opening for a bad joke is obvious) is to just taper the strips to a smaller dimension. But do I exalt size over function if I do that (another opening for a bad joke)? In other words, do I give up the power and flex of the bamboo that I plane off to make the right dimension and trade it for glue that adds nothing to the function of the rod (except to hold the strips together)? I conclude that while under-sizing the strips might fix the dimension problem, it is not a correct solution. Instead I have to focus on squeezing out more of the glue as I bind. Comments and thoughts? (Doug Hojem) My question is: Are you dry binding the strips, having relieved the apex as JW suggested, and measuring the result, all three ways of course? Even with strip dimensions apparently close to perfect, I find I am typically a bit oversize and need to take a bit more off the strips to get the desired flat to flat dimension. If you are not checking that, gluing up is a real act of faith and likely to lead to disappointment. A simple one-way hand binding is sufficient to do the check. To adjust the strips, I scrape the two strips with an oversize measurement in the form with a single edged razor blade plus and minus 2 1/2" on either side of an oversize position, proportional to the amount they are oversize. It sometimes takes me two or three cycles of dry hand binding, measuring and scraping to get what I want. I write down the result of the measurements each time so I know how much work I need to do (Mike McGuire) Not to hijack this thread but what Mike mentioned about dry binding hits home. My immediate problem is glue lines or I should say strips not fitting tightly enough in the swell area. Apparently I am not leaving my roughed strips large enough for planing to taper in this aream Learning curve here. My dry binding taught me to check and keep checking until 'it fits', then glue! (Don Smith) You might want to try removing some material from the pith side of your strips at the swell (like a 3/8" scallop as if you were hollowing) and again where the swell levels out, assuming it does. This should help with assembly and prevent the strips from wanting to splay out during glue up. (Chris Moore) Thanks for your suggestion. I narrowed the taper by -.020" (extreme?) and re-planed the strips again. Seems I had more of an issue of the apexes not being sharp. The strips were nesting together nice and tight, but because some of the apexes not being razor sharp, it appeared there were gaps all the way through. I may end up with a slight parabolic action when it is finished. Not the end of the world. (Don Green) You worry far too much, my friend. If the strips are accurate (measured with a calibrated micrometer accurate) and when you put them together with glue there are no gross glue lines to be found; but when you measure the blank and find it to be oversize by a thou or so, WHO CARES? It can only be glue. Same applies later to post-varnish measurements. IF THE CANE IS RIGHT, THE ROD IS RIGHT as far as I am concerned. The action of the rod is all that really matters. I have better things on which to fritter my remaining years than worrying about a thou of glue or varnish here or there. IF THE CANE IS RIGHT, AND THE ACTION IS RIGHT THEN THE ROD IS RIGHT. If you sell a rod to someone who proceeds to measure it twice a day on all three axes, every inch along the shaft, then don't sell him any more rods. Life is too short for that sort of fertilizer! (Peter McKean) You are right (IMHO). In MY case I'm not so concerned with the FINAL #'s as I am about the preponderance of GAPS in the glued up apexes. Whether they are subsequently filled with glue, bamboo sawdust or acrylic paint, as long as they are not showing when the blank is dipped or hand varnished, works for me! What my gaps tell me is my techniques are not right and need correcting. Recognizing what and how to correct my work is what IS important. What I have learned is that with swelled but forms my initial sizing of my strips after splitting need to be larger than +.010" to +.020" over the swell taper! (Don Smith) There are some nasty mathematical facts which will penalize lack of care about dimensions. A rough calculation shows this. Thirty feet of 4, 5, and 6 wt lines weigh 120, 140, and 160 grains respectively. So half a line weight more on a 5 wt would be 150 grains. So a "5.5" wt rod would be 150/140 = 1.07 stiffer that a "5.0" wt rod. The stiffness of a beam varies as the 4th power of its cross section dimension. To be 1.07 stiffer the dimension need to be the 4th root of 1.07 greater or 1.017, that is 1.7% larger. Now consider a typical taper in that line weight range, say 0.070" at the tip, 0.15" at the middle, and 0.300" at the butt. Now 1.7% of those numbers is 0.0012", 0.0026", and 0.0052". It's not real hard to be off that much, and thus end up with rod that's half a line weight heavier than intended. (Mike McGuire) Equally relevant is that no two line manufacturers manage the first 30' of their tapers in the same way, even though those 20-foot segments may weigh the same. And behind that 30' mark, the continuing tapers often differ still more. Such differences can sometimes affect a given rod by a full line weight. Couple this factor with the differences between one caster and the next, and it's still more likely that we could be "off" by a line-weight. So, whether it's the rod's math, the line manufacturer's taper, or the casting stroke, it's usually impossible to predict exactly how a rod designed for such-and-such weight will actually perform for a given fisherman. We come close, but nailing down all three of these factors is a pretty tall order. Regardless, it's nothing that should upset (or surprise) us, and this is why we learn to tweak our tapers. (Bill Harms) Even if a rod is designated for let's say a 5 weight. The rod is going to be able to use a line weight up or down. Case in point, I have an 8'6" Canadian Canoe rod that is designated for a 7 weight line. I did not have a 7 weight set up so I used a 6 weight on it this last weekend @ Lee's Ferry. I had no issues using a line weight under what was designated for the rod. (Bret Reiter) Well, isn't that just great, a Math guy comes along to really spice things up. I guess I would not have thought of things that way. On my last 2 rods I planned, I went over each station 3 times and measured and planing or scraping just a little bit more to get close to the demension. Now I am going to sand down the pith area down slowly and glue up a rod and see how things come out. My first 3 rods were over demension 3 or 5 thousands in some places and it really bothered me, but only I knew about it so I said the heck with everyone else's opinion... hee, hee I felt I was close or under on several of these rods, but I wonder now about the pith area throwing things off. So, Mike I hope you keep investigating stuff like this and pass it on to us other rodmakers. (Lew Boyko) Orvis and Walton Powell among others frequently referred to their rods in multiple line weights. Sensible, unless you want to sell a rod for each line wt. The classic makers had simple solutions for tweaking rods after glue up: scrape and sand. As long as you keep it to a few thou, taking off the power fibers won't matter too much from a practical standpoint. (Chris Moore) I used to be hung up about the right line for a rod. Then i was told to take a rod and a bunch of different lines and try them. So I took a 8ft 4 wt rod and started with a 3wt line. Ended up really liking the 8wt line on that rod commercially marked 4wt. I learned that...
Seems to me the rod is 4 or 5 or 8 or whatever weight with "x" foot of line out for a preference in casting style. No doubt someone else will take that rod and prefer a different weight line with a different casting action and a different length cast. I wonder if you ever use any quantitative (or semiquantitative) measure of your rods line weight like CC system? It is just a static deflection test but I have found it useful eg when comparing hex-quad-penta-triangle tapers. (Tapani Salmi) I have tried the CC system, but not found it very satisfactory for bamboo rods. It was sometimes two line weights under what I found best. On a newly finished rod, I cast lines of different weights to find the one that suits the rod best to my taste. (Mike McGuire) That's absolutely correct, Mike! The function of the rod is to cast a fly line. In different hands, the same rod may well function best with different-weight lines. What a rod owner needs to know is which line his rod casts FOR HIM. I am such a solidly bad caster, I can more or less grab any reel/ line combination to go with a rod; but I acknowledge most are more skillful than I. (Peter McKean) Also, different weight lines work well in different situations. Some times for example if it is windy it can work well to use a line one weight over. (Doug Hall) I think cc is just another static comparison. It does not take the mass of the rod into account. (Scott Grady) I think you nailed it there. It doesn't account for the mass which isn't much of an issue for graphite rods, but is for bamboo. So CC in my experience was reasonably good for graphite rods, but not for bamboo. (Mike McGuire) We had a CC demo at European RM Gathering (Sansepolcro). Measured several fine rods, I asked the builder what he thinks about the line weight of his rod and then measured CC - quite nice correlations, some small surprises. I could recommend that demo to any bamboo gathering. Personally, I like to compare "same" rods built using different techniques (hex-quad-tri etc) using CC. CC assumes the bending of rod to be 30% but most cane rods do bend much more when casting! That gives too small number like Mike said. (Tapani Salmi) So CC in my experience was reasonably good for graphite rods, but not for bamboo. I think so too. A few years back Bill Fink spent a lot of time with Common Cents, measuring a lot of rods, and trying to get the system to work with cane. He gave up after a lot of effort. In addition to the factors already mentioned, I thought that cane rods have more variations in taper types than graphite. You might be able to get the system to work right with fast action tapers, but what happens then if you test a parabolic taper? The taper programs like hexrod and RODdna can be very predictive if you are experienced in using them, and IMHO will get you closer than common cents, however, nothing replaces taking the rod out with several lines and casting it. (Tom Smithwick) I think Thomas Smithwick wrote the right thing, there are many variables that influence a taper and each system can only give a generic indication. (Alberto Poratelli) We're working on a program for SRG 2016 to "tune up" a rod by casting several different lines and line weights. The RIO representative was at the FFF conclave in Arkansas this year doing this program with a bunch of different lines. It would be expensive to line up enough reels to do this kind of tune up. RIO has the reels and lines set up for that purpose. It's not a sure thing yet, but we've made contact with the RIO rep and he's interested. It would be interesting to see how many different lines are the "best" for the same rod for several different casters. (David Bolin) I've mentioned this sort of thing before and people don't like me saying it but I think its worth saying again but there are times when the maths just wont do the whole job in a dynamic system. Until very recently I worked with light aircraft as a draughtsman. I worked in an office with about 40 engineers, very good ones too, some of them. The mob I worked with is developing a new aircraft and they were having problems with what's known as flutter in the tail. Flutter doesn't sound too bad but it's actually death on a stick and has to be resolved if you don't want everybody to die. There are designs and models used to develop wings and fins etc but you have to design these surfaces yourself ultimately. The flutter problem was persistent. The maths could only take things just so far and you then have to put a parachute in what amounts to a cannon on your plane for just in case, go to a remote place and and go suck it and see. They did this a few times and in the end they hired a guy from NASA to help them out, he did his calculations and guess what, still had flutter. They resolved the problem in the end but it was maths and trial and error in the end because in the real world things that are dynamic can almost chaotic as far as calculations go and this is what people don't like me telling them. If you don't have all of the facts or even if you do have all of the facts but do not use them correctly, you will get the wrong answer with complete confidence that you have the right one. A rod in use is dynamic, possibly chaotic. The Garrison model and those derived from it are sufficient to design a rod but in the end you have to try it. (Tony Young) Tony, in the relativistic paradigm, the maths can encompass anything at all; it is the mathematician who is not infallible. (Peter McKean) I had a list member ask me for an update on my quest to figure out what the issue is with my having over-sized blanks especially low in the butt section. The request was timely because just yesterday I finished the first blank that I had completed after having received the many helpful suggestions. The result was good. As a matter of fact, this blank is the first that I have done where I felt that I could put some kind of designation on the blank as to whose taper I used (this is a Garrison 212E) and not feel that I was insulting the rod designer. What I have to say is probably so ingrained to those of you with years of experience that this all sounds sort of "duh", but maybe for those who have only been doing this for a couple of years this may be helpful. I think a lot of factors were involved with my problem. Let me start with Harry Boyd's suggestion of binding dry with tape after tapering, and then measuring all the stations on the blank. I did that and found that I was over-sized in some of the stations (especially the low ones in the butt section). So I put the strips back onto the plane form and took some more bamboo off in accordance with the measurements. The final dry measurement was off a bit as compared to the post-glue measurement such that I have concluded that my glue (Nyatex) adds about .003 to the overall rod dimension in the lower end of the butt, and adds nothing above that. I suppose that the binding string has an easier job of compressing the strips together where they are thinner, thereby squeezing out more of the excess glue in those regions of the blank. Second, I think that Harry's suggestion that a lot of this could be due to measurement error was right. I made an effort to be sure to measure across all three flat-to-apex dimensions to assure that all made measurement. I think that the measurement from the pith apex to the opposite flat is the most suspect because that apex is soft and consequently easily crushed with the caliper jaws. But the two outside apexes are stiffer and will generate a more accurate dimension. I think that improved on the accuracy of my measurements. Third, I increased the amount of sanding I do to remove the pith side apex before gluing (to help the splines better nestle in together). On the butt section I did four passes of 400 grit sandpaper and on the tip sections I did three passes. (Before I had only been doing two). Fourth, it was suggested that I be careful to assure that the outside radius is flat, not rounded. A rounded outside flat does adds to that flat-to-apex measurement, and the rounded flat can cause the spline to rock in the planing form throwing off the 60-degree angle making for inconsistent depth. So with sandpaper and an L-N scraper I made sure that the outside radius was flat. And as to the 60-degree angle, this was the first rod that I did on my new (though purchased used) JW power bevelor (as we always say, I have no relationship with the company). And I have to say the 60-degree angle was right on consistently, so the three measurements per spline were very consistent. Not to mention the additional benefit of cutting beveling time by about 5 times with no pressure on my 65-year-old somewhat arthritic wrists. Great machine! Last, I think that I am getting better at the whole process. I am learning things with each rod, and they add up to better success. This rod is number 10 for me (in two years), and it is far better than anything I have done. So, I think I was dealing with several factors. Thanks for all the help. (Doug Hojem)
Several messages recently discussed the challenges of ending up with sections having exactly the measurements shown in the target taper. I've also recently read about some makers (like Winston) who apparently make up sections with a simple standard (linear?) taper and finish shaping them after they're glued up. I assume they do that with fine sanding blocks or files, carefully removing the same amount from each flat. When you look at the cross section of a strip, it doesn't look to me like it matters very much to remove 10 thous or so from the outer power fibers since they are present in the same density throughout the strip. So why bother working so hard to get exactly the right results on the forms? Why not intentionally shoot for slightly oversized strips and finish dimensioning them after they're glued up? I know it's "tradition" to worry over preservation of every power fiber but that isn't a very convincing argument for me. Anyone else have thoughts on this? (Barry Kling) Those oversizes are so large they strike me as being due to form setting errors. If you aren't already doing it, you need to recheck the setting each time until all are exactly where you want them. Because you are bending steel when setting the form, each adjustment has a minor effect on the others so I recheck each setting until all are correct. Also, try shaving between .003" and .005” off the pith side apex. If the strips are not exactly 60* (and few of mine are) the inside contact point of the 6 strips will interfere with each other. Relieving the pith side apex helps the strips nest together better. It also provides some space for excess glue to squeeze into in addition to the glue that squeezes outside. The tension you put on the blank when binding the strips also has an effect as does the kind of glue you are using. I use TB III and leave a .003 glue allowance when setting the form. This is tapering the strips to a smaller dimension. Personally, I am far more interested in getting as close to the target dimensions as possible than worrying about the effect of glue vs. power fibers and .003" is so small I doubt anyone would notice the effect. (JW Healy) If you are heat treating your strips and going straight to planing, that’s your problem. The bamboo shrinks during heat treating. After it comes out of the oven it can take weeks for it to re-absorb the moisture it lost depending on the humidity in your shop. I have made careful measurement to see how much the bamboo swell as it absorbs moisture. The answer is about 4%. That means a section that measures 0.100 dry will measure 0.104 when humidified. A 0.300 section will measure 0.312 when stabilized. This could be your reason for greater oversize at the butt end. (Al Baldauski) If that is the case that bamboo re-absorbs moisture, then how long after heat treating do you wait till you plane. (Lew Boyko) I tie my strips loosely together and place them in a 1 ½ inch, capped PVC tube that has a small puddle of water in the bottom. I suspend the strips so they DON’T touch the puddle. I leave them in the tube for 5 days then take them out and weigh one strip to within 0.1 grams. Usually there is extra moisture that needs to evaporate so I keep weighing the strip each day until the weight stabilizes. Usually two days. Then it’s time to plane. (Al Baldauski) I chased this problem for some time myself (butt too big). The answer in my case was two things. I found I was consistently planing strips with fat apex's i.e. over 60 degrees. If all your strips are this way they cannot nest together in the center. The glue lines will be tight and all looks ok. Second, I found that my 60-degree point on the depth gauge was off, resulting in form setting errors. This error became more pronounced as you progressed from tip to butt. Just a couple of thoughts for you. (Rick Hodges) There is little doubt that you are trying to make your strips as dimensionally accurate as possible. Let me throw out an idea and see if it sounds familiar. You have split your strips from the culm then you handle the nodes the way you usually do. Plane the pith off the inside of the strip. Now flatten the outside of the strip, remove the enamel. Ralph Moon usually scraped then sanded the strip flat after filing the nodes and straightening the strips. As a rule of thumb he insisted taking off the least amount possible, thereby leaving the greatest amount of power fibers. I could be wrong but I suspect, you have not flattened the outside of the strips sufficiently before you started planing the V. With the natural radius, or a radius on the outside of the strip it is virtually impossible to make accurately dimensioned strips. (Greg Shockley) What Greg says as per Ralph Moon right but from what more than a few people have written to me privately as the result of this thread it really does seem as if provided the splines are accurate the over size issue if that's what you could call it is overstated. One person in particular who I wont name because I'll leave it to him to out himself or not as he pleases has actually done the experiment of using the same taper and culm etc with different thickness of glue and the difference in deflection was found to be close enough to zero to not be concerned with. Peter McKean has made more than a few rods and I know he's accurate when it comes to his planing. If slight oversize was a real problem, Peter would have established it as being one but as he's pretty ambivalent about it within limits I'd be inclined to agree. I made 5 Driggs taper rods one after the other at one stage. The strips were accurate but my binder wasn't so good so they *can't* possibly have all been identical yet they all cast the same, I still have one of them. It was a while back now and there must have been slight differences as you'd expect but they were all definitely Driggs taper rods. Personally, I think you've answered the reason you're getting the butt sections oversize and not the tips yourself and it's down to the binder. The other thing to consider too is something that's been mentioned a lot in the past and will be again and that's that the original rods the tapers are derived from are rarely all that accurate to the point that the three flats are usually measured then averaged. That doesn't sound so accurate to me and I'd suggest that there are many people on this list who are making rods that all three flats are the same within plus or minus 0.003" which is EXTREMELY fine tolerance. That's machining tolerance. If the originals were made so the numbers have to be averaged I have to wonder what kind of variation there was from rod to rod? (Tony Young) Thank you for pointing that out, Greg. You have no idea how difficult it is to get this simple concept across to the "If you so much as sever one xylem or phloem strand lightning will strike you down and all your rods will be noodles" brigade. Rod building certainly seems to be the spiritual home of the urban myth! (Peter McKean) I have avoided contributing on this subject, but… It is NOT impossible to get accurately measured strips with the radius on the outside of the strip. I leave the radius on my strips, measure each strip at each station twice while planing (MHM), and then use a micrometer to measure the completed blank (all three axes) at each station. The results are both consistent, precise, and accurate. Does leaving the radius make my rods better? Haven’t a clue! Would flattening the enamel side make my measurements more accurate? Maybe, but the variations due to cane in rods with identical measurements are probably greater than any miniscule improvement in accuracy of measurement. (Tim Anderson) I love the rod list; it is so easy to get distracted. Tim, I have thought about it, but never enough to figure it out. I have sections of an Edwards, inherited from Ralph Moon, that has slightly radius flats. So, when you are measuring your strips, you are measuring from one of the to be glued flats to the opposing apex, then measuring from the other to be glued flat to the opposing apex? Providing they are equal, when glued up the measurement from apex to apex around the hexagon should be equal? The measurement flat to flat may very a few hundred thousandths unless the arc of radius was identical on each strip? The strips are so small, it would probably hard to measure much of a difference. As to whether or not a rod is better leaving the radius???? That would have been good for another year’s worth of discussions with Ralph, and would have provided at least another chapter in his book. The argument could be made; the more power fiber that are left on a strip, the better the rod will be. (Greg Shockley) I leave the enamel side till I get 40 to 50 thousands off the other 2 sides. Then I start scraping and putting a flat on the enamel side. At some point you have to get the enamel side started being flat to get good results on the other 2 sides. You do not want the enamel side to cause a rocking effect when planing the other 2 sides. But the final on the enamel side is finished when I am down to the final 10 thousandths or so on the strip. (Lew Boyko) You do make another point there that is well worth making - the inherent variation in properties of bamboo is so great that it certainly negates a lot of our finesse. (Peter McKean) I would agree with your comments about the inherent variations in the properties of bamboo. However, a number of years ago Ralph Moon and I built three rods, same taper, out of two culms. The rods were built in an assembly line of sorts. All the strips were split and numbered so opposing strips would come from opposing sides of the culm. We were quite careful to keep track of everything. All the strips were heat treated at the same time. After the ferrules were mounted, Ralph's waggle test was done on all three rods simultaneously. The oscillations were remarkably identical, obviously they could only be evaluated visually, Ralph was amazed at the consistency, I was equally surprised. The rods were for all intent and purpose indistinguishable from each other. I would not go so far as to say another myth is debunked. But I do think it demonstrates the consistency of the material we are using to build these rods and the forgiveness of the tapers, providing you are measuring to 0.001. (Greg Shockley) Our bamboo is surprisingly consistent, but does vary enough from culm to culm to be detectable in a finished rod. For example, I built two rods from two different culms (strips marked to make sure one rod was from one culm and the second rod from the other). Using my MHM, I planed the strips as if for a 12-strip rod. The strips were mixed randomly while planing. Heat treating, glue, etc. were all identical for the two rods. The blanks were essentially identical in dimensions: over the 19 stations external to the grip area (8’6” rods), the average variation in dimensions of the two rods was 0.153%. On completion, the two rods were compared by good casters at the Golden Gate Angling and Casting Club casting ponds. All agreed that one rod was softer than the other. The difference was not great, but was noticeable. The cane from the two culms was different while planing, so the results in casting were not a surprise for me. The people who have the rods say that the differences are not apparent when fishing. (Tim Anderson) That's right. It's pretty well all but impossible to really tell the dif between individual rods of a taper provided that same care is taken in making them. Way too many other things going on when fishing to be able to remember one rod from another or tell anyhow. (Tony Young) Well, my eyes aren't all that good but when I look at the cross section of a strip, the power fibers appear to me to get denser as they approach the enamel. I also find planing a lot easier and more accurate than sanding so I would rather plane to the surface of the form. I do "cheat" and sand oversized stations after I measure the glued up blank. I also feel that .010" is a bigger error than I am willing to live with. I do agree that an obsession with power fibers is a bit over the top. However, if you are satisfied with the results you get stick with your method. (JW Healy) Certainly when you look at a raw strip there is that increase in density toward the enamel. But in the tip and mid section final strips the less-dense material is gone and what is left is the highest density material. I see little or no gradation within that tiny portion of the original strip. In most of the butt and mid section there's plenty of bamboo for strength purposes and a few thous off the top are even less significant there. At least, that has been my experience. It is amazing how many variations there can be in making long bendy sticks for waving around near the water! (Barry Kling) You folks can go right ahead planing and sanding away outer fibers to "tune" your rods if you choose. Not for me. I will either hit the numbers I target or make another blank. And I'll even leave the outer radius on my strips to preserve those precious power fibers. I'm not necessarily right and you are not necessarily wrong. I just have a way of doing things that works for me. (Harry Boyd) In answer to Barry as to why not be oversize and sand or file to size. That scenario does not work well with very hollow walled rod sections. With a wall thickness of say 0.010” to 0.012" you don't have much room left to adjust by sanding without destroying the intended stiffness profile of your rod section. It is best to hit your numbers righ from the git-go. (Jerry Drake) I was given a big bunch of glued-up sections from one of the British makers, Sharps, I think from memory. These had been brought into Tasmania by an entepreneurial guide cum tackle shop proprietor with the intention of working the "blanks" into finished rods for sale. Thing was, the "blanks" arrived all the same size, as rough as guts, and ALL still in the string. It seemed as though the factory regarded it as normal to plane the outside. Those 1950's British rods were not exactly known for their great action, but to give them their due, they were durable enough. Point is, there are things in this craft which I regard as taboo that others take as quite normal practice. (Peter McKean) Thing is, back then men were made of iron and ships of wood and those one size becomes any blanks caught some seriously big fish combined with reels that had no drag.Couldn't do it now but does show what is possible. (Tony Young) No, Tony, he would not have told me anything of the kind. He was a pure mathematician, a Doctor of Science from London University, and a First from Oxford after the war, when such things were a lot rarer and harder to come by - and they ain't easy to come by even now. He was Visiting Fellow at Magdalen College, and Visiting Professorial Fellow at more universities in the US and Europe than you could easily count. All this after a whole war over Germany in either a Lancaster or a Mosquito, depending. Why would he not have told me anything like that? Because he was a real, professional mathematician, and he knew I would not have a bloody clue what he was talking about, any more than he would have understood in depth if Macfarlane Burnett had tried to explain antigenic determinants to him. He was quite tolerant of sort of "Scientific American" sort of expert, up to a point; but there was this kind of look on his face when lay people at social functions decided to impress him with their deep grasp of his subject. He rather liked veterinarians, because not only did we not know anything about anything other than horses, but we actually knew that was all we knew. That and beer, Rugby and playing 500 in the common room. The old Professor greatly admired a bloke in our year vet science, Rick Trivett, not for any academic excellence, but because he was a Wallaby a couple of years in a row. Had we been into rods in those halcyon days, I think it would have been in 64th's of an inch and whether they cast OK. We may have moved too far from what we know, I think. (Peter McKean) Doesn't take an expert at a great level to know there are limits to the maths especially when it comes to things involving feedback. To think otherwise is pure hubris. (Tony Young) This makes me reflect that you can’t have enough rods, if you fish different situations, as I do. And you don’t have to own them forever; focus on what works for you over time. Right now for 7’ rods and up, I’m enamoured of hollow builts, and I’m finding that the top prices are not necessarily the top performers for me. As an occasional rod maker, one can measure the outside taper, but not the inner. So, the hollow brigade has the sort of secret information that the old timers in the USA had in largely hex days.So, more experimentation, and how good is that! It interests me enough to give it a try. Dave Norling tells me he uses a simple shave off the apex approach as he’s satisfied the modern glues like Epon and its successors are quite capable to hold the narrower surfaces together. (there are different cutters available to flute the strips with a view to increase the surfaces for adhesion.) Berislav and I had a post-lunch try of four rods on the terrace today and it was wonderful. The better rods were quite parabolic with the bend into the handle. (Sean McSharry) Sean, are you doing the hollowing on the MHM with one of those fluting jigs Tom provides. I think Hayesie has one tucked away. He gave me that mill to unpack and get set up for him when it followed him back from the US, and I'm certain there was a fluter. I am also pretty sure Nick has some stuff on hollowing that came through Jeff. I made maybe ten rods with varying degrees of "dam-style" hollowing, but couldn't see where it was getting me, so stopped. Do you find a palpable improvement? (Peter McKean) I am of the school that espouses doing whatever you can to preserve the precious power fibers immediately below the enamel. With that said, I also believe it is much easier and faster to get it right before glue up than attempting to correct planning errors afterwards. Furthermore, I cannot see how in the world you can sand an oversized blank and hit the numbers with much accuracy. (Lou Barbaro) I've done it, Lou. Not really tough with a fine file like those sold as ferruling files by outfits like Golden Witch. Are you sure those fibers are so much more precious than the ones just under them? Seems more like tradition than information to me. (Barry Kling) I have read and had a little experience, but not enough to make any definitive statements, that if the sections are sanded too deep, they are more likely to take a set. I suspect there is also some interaction with heat-treating, and it is too complicated to sort out with the few data points with which I have had direct experience, but it would make a good experiment. (Bill Lamberson) I'm with Harry on this. (Hi Harry, been a couple years) Do it right or start over. I do believe every power fiber is needed and the outer one's the most. Sanding power fibers to hit numbers seems counter intuitive to me. I'd rather be over a couple thousandths. (Tom Kurtis) Yes, I agree, sanding and/or planing to hit numbers seems pointless.However, I flame my bamboo (moderate flaming) and have no hesitation in planing off the charred layer which is nothing but charcoal. This also achieves the desirable final smoothing of the nodal ridges so the strips sit accurately in the forms. In the interests of removing as little crust as possible, I do this as late in the strip planing process as possible. I have just repaired a fracture at the front (female) ferrule in a three-piece 5-weight - the third such fracture in about 250 rods, nearly all fished hard. This particular rod has been used hard in the Snowy Mountains for 6 or 7 years now. Point being that I do not think planing/sanding does NOT contribute to increased fragility. (Peter McKean) Makes sense. And we're only talking about the last few thous -- not even the thickness of the outer layer of fibers. Really I don't disagree with preserving all possible fibers, just wanting to put out there that there is a reasonable option when we miss a little. (Barry Kling) These questions have been covered in considerable detail in Wolfram Schott's papers, Bamboo under the Microscope and Bamboo in the Laboratory. On reading you may not be so comfortable with removing very much from the surface. (Mike McGuire) Bamboo behaves a lot like a composite rod. Surface fiber contribution is significant. Continuous fibers at the surface of a graphite rod blank usually range from 10% to 20% stiffer than a sanded blank. A center-ground or centerless-ground graphite blank will usually be designed with a slightly larger diameter, but will be lighter and cast faster due to lower wind drag. If we know we are sanding off the ridges left from the shrink wrap, we use a different taper and wall thickness schedule in the first place. Those "precious" outside power fibers are more important if the fiber density drops off down inside the triangular sections making up the hexagon. Good bamboo selection - thick walls with even fiber density - reduces this effect. Larger diameter butt sections are less affected by a little sanding than are thin tip sections. With as much work as goes into the blank alone, then to consider the whole rod, why would we settle for something different than we designed? I want an 11 foot, 9 weight, fast taper, and I'm going to invest a bunch of time and effort into it, I don't want to end up with a 10 foot 8 inch, 7 1/2 weight, medium action rod. I admit that is an exaggeration, but exaggeration illustrates the point. Harry's point makes a lot of sense. Mike points out that Schott's book leaves you with the same impression. Face it - we're fanatic flyfishers using cane rods anyways, so try to build a taper to blueprint instead of sanding it into a "kind of, sort of, almost" rod. These are our pride and joy, not a schileleigh. (Carey ??) I assure you that I can be as accurate in my work as the next man, and if the taper I choose calls for a dimension of 0.237", then it GETS a dimension of 0.237”! But having done the obsessive thing on bamboo measurements, as far as I am concerned that is it for the micrometer. From that point on, I am building a working fly rod and a couple of thou of varnish or glue worries me not at all. I see accuracy as a means to an end, not as an end in itself...... (Peter McKean) I agree. It's hard to imagine that if things are done carefully and as repeatably as possible it will matter very much. (Tony Young) You say shaping a section after gluing makes it a "kind of, sort of, almost" rod. I was wanting to suggest that small post-gluing adjustments (just a few thou on each flat) are an option -- in response to postings about sections that came out a bit off spec. Taking a few thous off a glued section doesn't make it a "kind of sort of" rod in my book. Precision is sometimes important, but in this case there are lots of factors along with dimension affecting how a section will work. Culms vary in fiber density, glues vary, etc etc. So this idea that precise adherence to a taper is critical, and that the only acceptable way to achieve it is with planes on a form, sounds great and scienterrific but it's based on an illusion. These are grass sticks, guys, not precision tools. I work in a field where precision really is important. But there are times when precision is an illusion in the sense that the things you can measure precisely aren't the only important factors. People make mistakes when they focus too much on the measurements in situations like that. And to denigrate the work of people who don't share the illusion is mistaken. I'm with the folks who know that tapers are a guideline but that excellent results don't depend only on taper dimensions. (Barry Kling) I don't see that the solution to the question as being that difficult. The right amount of glue to use is the minimum amount that will work. That's not difficult to achieve in a rod because it's bound and that causes squeeze out but this will vary between rods and users to some degree. If you plane the strips accurately they are measurably correct. That much is clear and straight forward. If you glue the strips to make the blank and the blank comes out as expected because the glue line is thin all is well. If you glue the blank and the blank is not as expected it has to be the glue. Now, does this matter? I don't really know but it's easy to work out if it bothers you. Take strips from the same section of a culm. Plane them identically and deliberately glue them into sections of a blank with different glue lines. Measure the deflection of the sections and see what you get.If the deflection is the same what's the problem? If they differ it's the glue and it makes a measurable difference in practice so use thinner glue lines. (Tony Young) EXACTLY, TONY, EXACTLY! Good on you! (Peter McKean) Do we believe there is any difference in rods with different geometry's? 3....12 sided. (Jerry Foster) As far as glue lines go? No. I would think that what applies for one geometry must apply for all. I couldn't even guess as to if a thick or thin glue line makes that much difference within the limits of a properly bound rod section. My gut feeling is that a thick glue line would be weaker because it's the cane that has the power fibers and even stiff glue is pretty flexible over a distance but I think you'd only know by experimenting. As far as different cross sections of different rod geometry go absolutely they're different. (Tony Young) I love a 12-sided blank! The nodes contribute so much less to weaken a section. Keeping them from lining up is the only headache, other than getting 12 sections accurately planed and tapered. Tony - I wonder if two identical blanks are made from "perfect" triangular sections, and one has a fatter glue line, was it the glue or was it the binding not giving even tension? (Casey ??) I would imagine it would be the binding. Glue has different viscosity at different temps and that may have an effect in extremes but the binding would be my first point of investigation. (Tony Young) Two questions:
And I'm with Harry - if it's over 0.002 - it's off to the trash. (Don Anderson) I agree that +-.002" is acceptable on a glued up blank but I do admit to cheating. If I am off up to +.004" I'll sand the offending flats to get to +.002". If I am under I check the stress curve of the actual dimensions and, if it looks interesting, I'll finish the blank and see if a "new" taper has evolved. My favorite 2 wt. was "developed" that way. I plane just the pith side flats but, after planing to final, I do scrape the enamel side in the form. This seems to correct very minor errors in the 60* angles and flattens the enamel side a bit. (JW Healy) Another case where you _may_ want to sand or scrape to final dimensions: where you have important changes going on between the 5-inch stations. Otherwise us hand planers are limited by what the planing form will let us do. (Frank Stetzer, Hexrod, Taper Archive, Rodmakers Archive) Actually it is possible to adjust a planing form between 5" stations. I have found with a C clamp, I can move my form in 3 or 4 thousandths, or be capturing the right size drill shank between the forms (below the apex of the groove) I can move it out a similar amount. It's fiddly, but it can be done if the need arises. (Mike McGuire) Is it possible that the cane, although hardened by heat treating, is 'rehydrating' by absorbing some of the glue or it's less viscous components? Could that account for the 'swelling' of the dimensions (Matt Woods)
Several weeks ago, I sent a message about my problem with my butt sections were routinely coming out large down near the stations where the grip and reel seat would be - as much as 10 or 11 thou too big for the first three or so stations. Then as the blank goes toward the ferrule things get more reasonable, and the tip sections have been pretty much OK. I thought I would give an update of my current rod after following all the suggestions. The suggestions included that I was probably not getting a good measurement of the strips (because the calipers would crush the apex's a bit) so I was actually going into binding too big to start with, that I should scrape the enamel side so that it was flat instead of naturally rounded, that my 60 degree angles were off, that I might try to bind a little tighter to squeeze out more glue...I think that was principally it. I was thinking that perhaps it was glue adding to the dimension and hypothesized that as the blank got smaller in diameter my binder did a better job of squeezing out the glue and that was why the tips were fine but the fat end of the butts exhibited the problem. Harry Boyd offered that if it is the glue that is the problem, I should dry bind the strips with tape and measure the blank, and then if I found disparities I could plane some more before binding and gluing. If (as Harry's thought goes), the dry measurement was good, and then if the post-glue measurement was over-sized maybe I could conclude that glue is the problem. So here is what I did. First, let me say my glue is Nyatex, and I really like the workability of that stuff. In terms of process, I planed and scraped to finished taper, scraped the enamel side flat, measured across all three flats, found them to be one or two thou off at the most when not right on, taped the blank tightly on both sides of the station marks, and measured dry. The results were very acceptable (some right on, some 1 to 3 thou off, and one 5 thou off at a troublesome node). I dressed up the tough node and did a little scraping at the stations that were over-sized. So, in theory, gluing and binding at that point should result in a rod that was pretty much right on unless the glue adds width. So as suggested, I tightened up the tension on my binder, glued, bound, 24 hours later removed the thread, cleaned up the blank, corrected a couple of minor twists and bends near the tips, re-bound and heat set. The rebinding was done with the binder tension still cranked up. Results: dimension wise the tip sections were right on with variances no greater than .002 except for one station .003 over. The butt? Very acceptable until the last four stations closest to the butt where my blank went from .003 over, to .005 over, to .010 over, to .011 over (the last three stations should have been the same). I can live having my rods over-sized under the grip and reel seat. Heck a lot of the old tapers have swelled butts under the grip and reel seat. So, I still guess that glue is the problem and my binder just does not squeeze out the excess at the butt end (but a flaw in that conclusion is that I do not have glue lines to suggest anything like that is happening). So, it is still a mystery to me. But, the tightened binder caused the tips to come out horribly twisted. If you lay the tip sections down on the work bench, the flat that starts on the top at the ferrule is about 90 degrees off at the tip. The butt did not twist. I either missed this big twist before rebinding, or the twist occurred when I re-bound. I am trying to salvage the tips with heating and corrective twisting, and when I go through the drill it works until the next morning when the twist has returned. I am going to give the heating and twisting one more go, and if unsuccessful I will scrap the tips (unless anyone has any other ideas). Aggravating, but I still love it..... (Doug Hojem) Very baffling about your butt measurements being off so much. I sand my enamel side a bit right before final planing to make sure I get 60 deg. I don't know (remember) what type of glue binder you have but (not butt) you should always use a lighter tension for your tips than either butts or sometimes mid sections. Myself, I do not vary the string tension on my Garrison-style glue binder, but do on my feed cord. When I forgot to swap weights out, I got nasty tips. I also do not cater for my glue (Titebond III) and take a whisker extra off when final sanding. So far, do good...... (Tom Lucas) I know your frustration with binding and twists. I built a 4 string binder just by looking at pictures of other rodmakers binders. I take a trigger pull gauge and measure the tension on each string site. I have mine down to 1 pound or a smidge less per tension tightener. You do not want to set the tension that you choke the hell out of the strips. This is especially true with the tip section. I also start binding each section butt first, no matter if it is the butt section or a tip section. I want the thick (butt of the tip section) going in the binder first. So, if the butt section is really bugging you, take .010 off those last couple station and see what happens then. (Lew Boyko) Here is one more suggestion that might help if you are heat setting the Nyatex. After the glue has set, but before heat setting, strip of the string and scrape the glue off the outside. Rebind with D size nylon rod wrapping thread with a fairly close wrap over those butt sections that are coming up oversized. Since the sections are not sticky anymore, it's not hard to do this by hand. Now heat set it. The heat will shrink the nylon, pulling those strips in tighter. If this will work for you, you may be able to lighten up on your binder tension and avoid the problems that creates. I use epon for gluing and do this as my general practice. I have closed up any occasional glue line that turns up using this technique. (Mike McGuire)
|
